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83ede847e8
2012-12-11 Richard Biener <rguenther@suse.de> PR tree-optimization/55079 * tree-vrp.c (extract_range_from_binary_expr_1): Handle MAX/MIN_EXPR for more cases. (register_edge_assert_for_2): Register asserts for post-in/decrement tests. (check_array_ref): Dump what expression we emit array bound warnings for. (search_for_addr_array): Likewise. * gcc.dg/Warray-bounds-9.c: New testcase. * gcc.dg/Warray-bounds-10.c: Likewise. * gcc.dg/tree-ssa/ssa-pre-1.c: Adjust. From-SVN: r194388
9336 lines
269 KiB
C
9336 lines
269 KiB
C
/* Support routines for Value Range Propagation (VRP).
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Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012
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Free Software Foundation, Inc.
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Contributed by Diego Novillo <dnovillo@redhat.com>.
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This file is part of GCC.
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GCC is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3, or (at your option)
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any later version.
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GCC is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with GCC; see the file COPYING3. If not see
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<http://www.gnu.org/licenses/>. */
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#include "config.h"
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#include "system.h"
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#include "coretypes.h"
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#include "tm.h"
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#include "ggc.h"
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#include "flags.h"
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#include "tree.h"
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#include "basic-block.h"
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#include "tree-flow.h"
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#include "tree-pass.h"
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#include "tree-dump.h"
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#include "gimple-pretty-print.h"
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#include "diagnostic-core.h"
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#include "intl.h"
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#include "cfgloop.h"
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#include "tree-scalar-evolution.h"
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#include "tree-ssa-propagate.h"
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#include "tree-chrec.h"
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#include "gimple-fold.h"
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#include "expr.h"
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#include "optabs.h"
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/* Type of value ranges. See value_range_d for a description of these
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types. */
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enum value_range_type { VR_UNDEFINED, VR_RANGE, VR_ANTI_RANGE, VR_VARYING };
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/* Range of values that can be associated with an SSA_NAME after VRP
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has executed. */
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struct value_range_d
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{
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/* Lattice value represented by this range. */
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enum value_range_type type;
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/* Minimum and maximum values represented by this range. These
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values should be interpreted as follows:
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- If TYPE is VR_UNDEFINED or VR_VARYING then MIN and MAX must
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be NULL.
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- If TYPE == VR_RANGE then MIN holds the minimum value and
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MAX holds the maximum value of the range [MIN, MAX].
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- If TYPE == ANTI_RANGE the variable is known to NOT
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take any values in the range [MIN, MAX]. */
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tree min;
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tree max;
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/* Set of SSA names whose value ranges are equivalent to this one.
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This set is only valid when TYPE is VR_RANGE or VR_ANTI_RANGE. */
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bitmap equiv;
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};
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typedef struct value_range_d value_range_t;
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#define VR_INITIALIZER { VR_UNDEFINED, NULL_TREE, NULL_TREE, NULL }
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/* Set of SSA names found live during the RPO traversal of the function
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for still active basic-blocks. */
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static sbitmap *live;
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/* Return true if the SSA name NAME is live on the edge E. */
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static bool
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live_on_edge (edge e, tree name)
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{
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return (live[e->dest->index]
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&& bitmap_bit_p (live[e->dest->index], SSA_NAME_VERSION (name)));
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}
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/* Local functions. */
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static int compare_values (tree val1, tree val2);
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static int compare_values_warnv (tree val1, tree val2, bool *);
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static void vrp_meet (value_range_t *, value_range_t *);
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static void vrp_intersect_ranges (value_range_t *, value_range_t *);
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static tree vrp_evaluate_conditional_warnv_with_ops (enum tree_code,
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tree, tree, bool, bool *,
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bool *);
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/* Location information for ASSERT_EXPRs. Each instance of this
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structure describes an ASSERT_EXPR for an SSA name. Since a single
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SSA name may have more than one assertion associated with it, these
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locations are kept in a linked list attached to the corresponding
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SSA name. */
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struct assert_locus_d
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{
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/* Basic block where the assertion would be inserted. */
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basic_block bb;
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/* Some assertions need to be inserted on an edge (e.g., assertions
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generated by COND_EXPRs). In those cases, BB will be NULL. */
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edge e;
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/* Pointer to the statement that generated this assertion. */
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gimple_stmt_iterator si;
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/* Predicate code for the ASSERT_EXPR. Must be COMPARISON_CLASS_P. */
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enum tree_code comp_code;
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/* Value being compared against. */
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tree val;
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/* Expression to compare. */
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tree expr;
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/* Next node in the linked list. */
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struct assert_locus_d *next;
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};
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typedef struct assert_locus_d *assert_locus_t;
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/* If bit I is present, it means that SSA name N_i has a list of
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assertions that should be inserted in the IL. */
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static bitmap need_assert_for;
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/* Array of locations lists where to insert assertions. ASSERTS_FOR[I]
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holds a list of ASSERT_LOCUS_T nodes that describe where
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ASSERT_EXPRs for SSA name N_I should be inserted. */
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static assert_locus_t *asserts_for;
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/* Value range array. After propagation, VR_VALUE[I] holds the range
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of values that SSA name N_I may take. */
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static unsigned num_vr_values;
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static value_range_t **vr_value;
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static bool values_propagated;
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/* For a PHI node which sets SSA name N_I, VR_COUNTS[I] holds the
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number of executable edges we saw the last time we visited the
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node. */
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static int *vr_phi_edge_counts;
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typedef struct {
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gimple stmt;
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tree vec;
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} switch_update;
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static vec<edge> to_remove_edges;
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static vec<switch_update> to_update_switch_stmts;
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/* Return the maximum value for TYPE. */
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static inline tree
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vrp_val_max (const_tree type)
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{
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if (!INTEGRAL_TYPE_P (type))
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return NULL_TREE;
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return TYPE_MAX_VALUE (type);
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}
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/* Return the minimum value for TYPE. */
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static inline tree
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vrp_val_min (const_tree type)
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{
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if (!INTEGRAL_TYPE_P (type))
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return NULL_TREE;
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return TYPE_MIN_VALUE (type);
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}
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/* Return whether VAL is equal to the maximum value of its type. This
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will be true for a positive overflow infinity. We can't do a
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simple equality comparison with TYPE_MAX_VALUE because C typedefs
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and Ada subtypes can produce types whose TYPE_MAX_VALUE is not ==
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to the integer constant with the same value in the type. */
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static inline bool
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vrp_val_is_max (const_tree val)
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{
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tree type_max = vrp_val_max (TREE_TYPE (val));
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return (val == type_max
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|| (type_max != NULL_TREE
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&& operand_equal_p (val, type_max, 0)));
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}
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/* Return whether VAL is equal to the minimum value of its type. This
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will be true for a negative overflow infinity. */
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static inline bool
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vrp_val_is_min (const_tree val)
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{
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tree type_min = vrp_val_min (TREE_TYPE (val));
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return (val == type_min
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|| (type_min != NULL_TREE
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&& operand_equal_p (val, type_min, 0)));
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}
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/* Return whether TYPE should use an overflow infinity distinct from
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TYPE_{MIN,MAX}_VALUE. We use an overflow infinity value to
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represent a signed overflow during VRP computations. An infinity
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is distinct from a half-range, which will go from some number to
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TYPE_{MIN,MAX}_VALUE. */
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static inline bool
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needs_overflow_infinity (const_tree type)
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{
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return INTEGRAL_TYPE_P (type) && !TYPE_OVERFLOW_WRAPS (type);
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}
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/* Return whether TYPE can support our overflow infinity
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representation: we use the TREE_OVERFLOW flag, which only exists
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for constants. If TYPE doesn't support this, we don't optimize
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cases which would require signed overflow--we drop them to
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VARYING. */
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static inline bool
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supports_overflow_infinity (const_tree type)
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{
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tree min = vrp_val_min (type), max = vrp_val_max (type);
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#ifdef ENABLE_CHECKING
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gcc_assert (needs_overflow_infinity (type));
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#endif
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return (min != NULL_TREE
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&& CONSTANT_CLASS_P (min)
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&& max != NULL_TREE
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&& CONSTANT_CLASS_P (max));
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}
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/* VAL is the maximum or minimum value of a type. Return a
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corresponding overflow infinity. */
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static inline tree
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make_overflow_infinity (tree val)
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{
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gcc_checking_assert (val != NULL_TREE && CONSTANT_CLASS_P (val));
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val = copy_node (val);
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TREE_OVERFLOW (val) = 1;
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return val;
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}
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/* Return a negative overflow infinity for TYPE. */
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static inline tree
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negative_overflow_infinity (tree type)
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{
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gcc_checking_assert (supports_overflow_infinity (type));
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return make_overflow_infinity (vrp_val_min (type));
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}
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/* Return a positive overflow infinity for TYPE. */
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static inline tree
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positive_overflow_infinity (tree type)
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{
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gcc_checking_assert (supports_overflow_infinity (type));
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return make_overflow_infinity (vrp_val_max (type));
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}
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/* Return whether VAL is a negative overflow infinity. */
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static inline bool
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is_negative_overflow_infinity (const_tree val)
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{
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return (needs_overflow_infinity (TREE_TYPE (val))
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&& CONSTANT_CLASS_P (val)
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&& TREE_OVERFLOW (val)
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&& vrp_val_is_min (val));
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}
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/* Return whether VAL is a positive overflow infinity. */
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static inline bool
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is_positive_overflow_infinity (const_tree val)
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{
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return (needs_overflow_infinity (TREE_TYPE (val))
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&& CONSTANT_CLASS_P (val)
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&& TREE_OVERFLOW (val)
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&& vrp_val_is_max (val));
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}
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/* Return whether VAL is a positive or negative overflow infinity. */
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static inline bool
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is_overflow_infinity (const_tree val)
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{
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return (needs_overflow_infinity (TREE_TYPE (val))
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&& CONSTANT_CLASS_P (val)
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&& TREE_OVERFLOW (val)
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&& (vrp_val_is_min (val) || vrp_val_is_max (val)));
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}
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/* Return whether STMT has a constant rhs that is_overflow_infinity. */
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static inline bool
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stmt_overflow_infinity (gimple stmt)
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{
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if (is_gimple_assign (stmt)
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&& get_gimple_rhs_class (gimple_assign_rhs_code (stmt)) ==
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GIMPLE_SINGLE_RHS)
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return is_overflow_infinity (gimple_assign_rhs1 (stmt));
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return false;
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}
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/* If VAL is now an overflow infinity, return VAL. Otherwise, return
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the same value with TREE_OVERFLOW clear. This can be used to avoid
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confusing a regular value with an overflow value. */
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static inline tree
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avoid_overflow_infinity (tree val)
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{
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if (!is_overflow_infinity (val))
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return val;
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if (vrp_val_is_max (val))
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return vrp_val_max (TREE_TYPE (val));
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else
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{
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gcc_checking_assert (vrp_val_is_min (val));
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return vrp_val_min (TREE_TYPE (val));
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}
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}
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/* Return true if ARG is marked with the nonnull attribute in the
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current function signature. */
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static bool
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nonnull_arg_p (const_tree arg)
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{
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tree t, attrs, fntype;
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unsigned HOST_WIDE_INT arg_num;
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gcc_assert (TREE_CODE (arg) == PARM_DECL && POINTER_TYPE_P (TREE_TYPE (arg)));
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/* The static chain decl is always non null. */
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if (arg == cfun->static_chain_decl)
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return true;
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fntype = TREE_TYPE (current_function_decl);
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for (attrs = TYPE_ATTRIBUTES (fntype); attrs; attrs = TREE_CHAIN (attrs))
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{
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attrs = lookup_attribute ("nonnull", attrs);
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/* If "nonnull" wasn't specified, we know nothing about the argument. */
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if (attrs == NULL_TREE)
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return false;
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/* If "nonnull" applies to all the arguments, then ARG is non-null. */
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if (TREE_VALUE (attrs) == NULL_TREE)
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return true;
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/* Get the position number for ARG in the function signature. */
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for (arg_num = 1, t = DECL_ARGUMENTS (current_function_decl);
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t;
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t = DECL_CHAIN (t), arg_num++)
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{
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if (t == arg)
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break;
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}
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gcc_assert (t == arg);
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/* Now see if ARG_NUM is mentioned in the nonnull list. */
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for (t = TREE_VALUE (attrs); t; t = TREE_CHAIN (t))
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{
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if (compare_tree_int (TREE_VALUE (t), arg_num) == 0)
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return true;
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}
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}
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return false;
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}
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/* Set value range VR to VR_UNDEFINED. */
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static inline void
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set_value_range_to_undefined (value_range_t *vr)
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{
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vr->type = VR_UNDEFINED;
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vr->min = vr->max = NULL_TREE;
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if (vr->equiv)
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bitmap_clear (vr->equiv);
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}
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/* Set value range VR to VR_VARYING. */
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static inline void
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set_value_range_to_varying (value_range_t *vr)
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{
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vr->type = VR_VARYING;
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vr->min = vr->max = NULL_TREE;
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if (vr->equiv)
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bitmap_clear (vr->equiv);
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}
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/* Set value range VR to {T, MIN, MAX, EQUIV}. */
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static void
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set_value_range (value_range_t *vr, enum value_range_type t, tree min,
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tree max, bitmap equiv)
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{
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#if defined ENABLE_CHECKING
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/* Check the validity of the range. */
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if (t == VR_RANGE || t == VR_ANTI_RANGE)
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{
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int cmp;
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gcc_assert (min && max);
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if (INTEGRAL_TYPE_P (TREE_TYPE (min)) && t == VR_ANTI_RANGE)
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gcc_assert (!vrp_val_is_min (min) || !vrp_val_is_max (max));
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cmp = compare_values (min, max);
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gcc_assert (cmp == 0 || cmp == -1 || cmp == -2);
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if (needs_overflow_infinity (TREE_TYPE (min)))
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gcc_assert (!is_overflow_infinity (min)
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|| !is_overflow_infinity (max));
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}
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if (t == VR_UNDEFINED || t == VR_VARYING)
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gcc_assert (min == NULL_TREE && max == NULL_TREE);
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if (t == VR_UNDEFINED || t == VR_VARYING)
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gcc_assert (equiv == NULL || bitmap_empty_p (equiv));
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#endif
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vr->type = t;
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vr->min = min;
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vr->max = max;
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/* Since updating the equivalence set involves deep copying the
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bitmaps, only do it if absolutely necessary. */
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if (vr->equiv == NULL
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&& equiv != NULL)
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vr->equiv = BITMAP_ALLOC (NULL);
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if (equiv != vr->equiv)
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{
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if (equiv && !bitmap_empty_p (equiv))
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bitmap_copy (vr->equiv, equiv);
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else
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bitmap_clear (vr->equiv);
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}
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}
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/* Set value range VR to the canonical form of {T, MIN, MAX, EQUIV}.
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This means adjusting T, MIN and MAX representing the case of a
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wrapping range with MAX < MIN covering [MIN, type_max] U [type_min, MAX]
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as anti-rage ~[MAX+1, MIN-1]. Likewise for wrapping anti-ranges.
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In corner cases where MAX+1 or MIN-1 wraps this will fall back
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to varying.
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This routine exists to ease canonicalization in the case where we
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extract ranges from var + CST op limit. */
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static void
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set_and_canonicalize_value_range (value_range_t *vr, enum value_range_type t,
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tree min, tree max, bitmap equiv)
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{
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/* Use the canonical setters for VR_UNDEFINED and VR_VARYING. */
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if (t == VR_UNDEFINED)
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{
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set_value_range_to_undefined (vr);
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return;
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}
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else if (t == VR_VARYING)
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{
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set_value_range_to_varying (vr);
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return;
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}
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/* Nothing to canonicalize for symbolic ranges. */
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if (TREE_CODE (min) != INTEGER_CST
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|| TREE_CODE (max) != INTEGER_CST)
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{
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set_value_range (vr, t, min, max, equiv);
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return;
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}
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/* Wrong order for min and max, to swap them and the VR type we need
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to adjust them. */
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if (tree_int_cst_lt (max, min))
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{
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tree one, tmp;
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/* For one bit precision if max < min, then the swapped
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range covers all values, so for VR_RANGE it is varying and
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for VR_ANTI_RANGE empty range, so drop to varying as well. */
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if (TYPE_PRECISION (TREE_TYPE (min)) == 1)
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{
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set_value_range_to_varying (vr);
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return;
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}
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one = build_int_cst (TREE_TYPE (min), 1);
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tmp = int_const_binop (PLUS_EXPR, max, one);
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max = int_const_binop (MINUS_EXPR, min, one);
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|
min = tmp;
|
|
|
|
/* There's one corner case, if we had [C+1, C] before we now have
|
|
that again. But this represents an empty value range, so drop
|
|
to varying in this case. */
|
|
if (tree_int_cst_lt (max, min))
|
|
{
|
|
set_value_range_to_varying (vr);
|
|
return;
|
|
}
|
|
|
|
t = t == VR_RANGE ? VR_ANTI_RANGE : VR_RANGE;
|
|
}
|
|
|
|
/* Anti-ranges that can be represented as ranges should be so. */
|
|
if (t == VR_ANTI_RANGE)
|
|
{
|
|
bool is_min = vrp_val_is_min (min);
|
|
bool is_max = vrp_val_is_max (max);
|
|
|
|
if (is_min && is_max)
|
|
{
|
|
/* We cannot deal with empty ranges, drop to varying.
|
|
??? This could be VR_UNDEFINED instead. */
|
|
set_value_range_to_varying (vr);
|
|
return;
|
|
}
|
|
else if (TYPE_PRECISION (TREE_TYPE (min)) == 1
|
|
&& (is_min || is_max))
|
|
{
|
|
/* Non-empty boolean ranges can always be represented
|
|
as a singleton range. */
|
|
if (is_min)
|
|
min = max = vrp_val_max (TREE_TYPE (min));
|
|
else
|
|
min = max = vrp_val_min (TREE_TYPE (min));
|
|
t = VR_RANGE;
|
|
}
|
|
else if (is_min
|
|
/* As a special exception preserve non-null ranges. */
|
|
&& !(TYPE_UNSIGNED (TREE_TYPE (min))
|
|
&& integer_zerop (max)))
|
|
{
|
|
tree one = build_int_cst (TREE_TYPE (max), 1);
|
|
min = int_const_binop (PLUS_EXPR, max, one);
|
|
max = vrp_val_max (TREE_TYPE (max));
|
|
t = VR_RANGE;
|
|
}
|
|
else if (is_max)
|
|
{
|
|
tree one = build_int_cst (TREE_TYPE (min), 1);
|
|
max = int_const_binop (MINUS_EXPR, min, one);
|
|
min = vrp_val_min (TREE_TYPE (min));
|
|
t = VR_RANGE;
|
|
}
|
|
}
|
|
|
|
/* Drop [-INF(OVF), +INF(OVF)] to varying. */
|
|
if (needs_overflow_infinity (TREE_TYPE (min))
|
|
&& is_overflow_infinity (min)
|
|
&& is_overflow_infinity (max))
|
|
{
|
|
set_value_range_to_varying (vr);
|
|
return;
|
|
}
|
|
|
|
set_value_range (vr, t, min, max, equiv);
|
|
}
|
|
|
|
/* Copy value range FROM into value range TO. */
|
|
|
|
static inline void
|
|
copy_value_range (value_range_t *to, value_range_t *from)
|
|
{
|
|
set_value_range (to, from->type, from->min, from->max, from->equiv);
|
|
}
|
|
|
|
/* Set value range VR to a single value. This function is only called
|
|
with values we get from statements, and exists to clear the
|
|
TREE_OVERFLOW flag so that we don't think we have an overflow
|
|
infinity when we shouldn't. */
|
|
|
|
static inline void
|
|
set_value_range_to_value (value_range_t *vr, tree val, bitmap equiv)
|
|
{
|
|
gcc_assert (is_gimple_min_invariant (val));
|
|
val = avoid_overflow_infinity (val);
|
|
set_value_range (vr, VR_RANGE, val, val, equiv);
|
|
}
|
|
|
|
/* Set value range VR to a non-negative range of type TYPE.
|
|
OVERFLOW_INFINITY indicates whether to use an overflow infinity
|
|
rather than TYPE_MAX_VALUE; this should be true if we determine
|
|
that the range is nonnegative based on the assumption that signed
|
|
overflow does not occur. */
|
|
|
|
static inline void
|
|
set_value_range_to_nonnegative (value_range_t *vr, tree type,
|
|
bool overflow_infinity)
|
|
{
|
|
tree zero;
|
|
|
|
if (overflow_infinity && !supports_overflow_infinity (type))
|
|
{
|
|
set_value_range_to_varying (vr);
|
|
return;
|
|
}
|
|
|
|
zero = build_int_cst (type, 0);
|
|
set_value_range (vr, VR_RANGE, zero,
|
|
(overflow_infinity
|
|
? positive_overflow_infinity (type)
|
|
: TYPE_MAX_VALUE (type)),
|
|
vr->equiv);
|
|
}
|
|
|
|
/* Set value range VR to a non-NULL range of type TYPE. */
|
|
|
|
static inline void
|
|
set_value_range_to_nonnull (value_range_t *vr, tree type)
|
|
{
|
|
tree zero = build_int_cst (type, 0);
|
|
set_value_range (vr, VR_ANTI_RANGE, zero, zero, vr->equiv);
|
|
}
|
|
|
|
|
|
/* Set value range VR to a NULL range of type TYPE. */
|
|
|
|
static inline void
|
|
set_value_range_to_null (value_range_t *vr, tree type)
|
|
{
|
|
set_value_range_to_value (vr, build_int_cst (type, 0), vr->equiv);
|
|
}
|
|
|
|
|
|
/* Set value range VR to a range of a truthvalue of type TYPE. */
|
|
|
|
static inline void
|
|
set_value_range_to_truthvalue (value_range_t *vr, tree type)
|
|
{
|
|
if (TYPE_PRECISION (type) == 1)
|
|
set_value_range_to_varying (vr);
|
|
else
|
|
set_value_range (vr, VR_RANGE,
|
|
build_int_cst (type, 0), build_int_cst (type, 1),
|
|
vr->equiv);
|
|
}
|
|
|
|
|
|
/* If abs (min) < abs (max), set VR to [-max, max], if
|
|
abs (min) >= abs (max), set VR to [-min, min]. */
|
|
|
|
static void
|
|
abs_extent_range (value_range_t *vr, tree min, tree max)
|
|
{
|
|
int cmp;
|
|
|
|
gcc_assert (TREE_CODE (min) == INTEGER_CST);
|
|
gcc_assert (TREE_CODE (max) == INTEGER_CST);
|
|
gcc_assert (INTEGRAL_TYPE_P (TREE_TYPE (min)));
|
|
gcc_assert (!TYPE_UNSIGNED (TREE_TYPE (min)));
|
|
min = fold_unary (ABS_EXPR, TREE_TYPE (min), min);
|
|
max = fold_unary (ABS_EXPR, TREE_TYPE (max), max);
|
|
if (TREE_OVERFLOW (min) || TREE_OVERFLOW (max))
|
|
{
|
|
set_value_range_to_varying (vr);
|
|
return;
|
|
}
|
|
cmp = compare_values (min, max);
|
|
if (cmp == -1)
|
|
min = fold_unary (NEGATE_EXPR, TREE_TYPE (min), max);
|
|
else if (cmp == 0 || cmp == 1)
|
|
{
|
|
max = min;
|
|
min = fold_unary (NEGATE_EXPR, TREE_TYPE (min), min);
|
|
}
|
|
else
|
|
{
|
|
set_value_range_to_varying (vr);
|
|
return;
|
|
}
|
|
set_and_canonicalize_value_range (vr, VR_RANGE, min, max, NULL);
|
|
}
|
|
|
|
|
|
/* Return value range information for VAR.
|
|
|
|
If we have no values ranges recorded (ie, VRP is not running), then
|
|
return NULL. Otherwise create an empty range if none existed for VAR. */
|
|
|
|
static value_range_t *
|
|
get_value_range (const_tree var)
|
|
{
|
|
static const struct value_range_d vr_const_varying
|
|
= { VR_VARYING, NULL_TREE, NULL_TREE, NULL };
|
|
value_range_t *vr;
|
|
tree sym;
|
|
unsigned ver = SSA_NAME_VERSION (var);
|
|
|
|
/* If we have no recorded ranges, then return NULL. */
|
|
if (! vr_value)
|
|
return NULL;
|
|
|
|
/* If we query the range for a new SSA name return an unmodifiable VARYING.
|
|
We should get here at most from the substitute-and-fold stage which
|
|
will never try to change values. */
|
|
if (ver >= num_vr_values)
|
|
return CONST_CAST (value_range_t *, &vr_const_varying);
|
|
|
|
vr = vr_value[ver];
|
|
if (vr)
|
|
return vr;
|
|
|
|
/* After propagation finished do not allocate new value-ranges. */
|
|
if (values_propagated)
|
|
return CONST_CAST (value_range_t *, &vr_const_varying);
|
|
|
|
/* Create a default value range. */
|
|
vr_value[ver] = vr = XCNEW (value_range_t);
|
|
|
|
/* Defer allocating the equivalence set. */
|
|
vr->equiv = NULL;
|
|
|
|
/* If VAR is a default definition of a parameter, the variable can
|
|
take any value in VAR's type. */
|
|
if (SSA_NAME_IS_DEFAULT_DEF (var))
|
|
{
|
|
sym = SSA_NAME_VAR (var);
|
|
if (TREE_CODE (sym) == PARM_DECL)
|
|
{
|
|
/* Try to use the "nonnull" attribute to create ~[0, 0]
|
|
anti-ranges for pointers. Note that this is only valid with
|
|
default definitions of PARM_DECLs. */
|
|
if (POINTER_TYPE_P (TREE_TYPE (sym))
|
|
&& nonnull_arg_p (sym))
|
|
set_value_range_to_nonnull (vr, TREE_TYPE (sym));
|
|
else
|
|
set_value_range_to_varying (vr);
|
|
}
|
|
else if (TREE_CODE (sym) == RESULT_DECL
|
|
&& DECL_BY_REFERENCE (sym))
|
|
set_value_range_to_nonnull (vr, TREE_TYPE (sym));
|
|
}
|
|
|
|
return vr;
|
|
}
|
|
|
|
/* Return true, if VAL1 and VAL2 are equal values for VRP purposes. */
|
|
|
|
static inline bool
|
|
vrp_operand_equal_p (const_tree val1, const_tree val2)
|
|
{
|
|
if (val1 == val2)
|
|
return true;
|
|
if (!val1 || !val2 || !operand_equal_p (val1, val2, 0))
|
|
return false;
|
|
if (is_overflow_infinity (val1))
|
|
return is_overflow_infinity (val2);
|
|
return true;
|
|
}
|
|
|
|
/* Return true, if the bitmaps B1 and B2 are equal. */
|
|
|
|
static inline bool
|
|
vrp_bitmap_equal_p (const_bitmap b1, const_bitmap b2)
|
|
{
|
|
return (b1 == b2
|
|
|| ((!b1 || bitmap_empty_p (b1))
|
|
&& (!b2 || bitmap_empty_p (b2)))
|
|
|| (b1 && b2
|
|
&& bitmap_equal_p (b1, b2)));
|
|
}
|
|
|
|
/* Update the value range and equivalence set for variable VAR to
|
|
NEW_VR. Return true if NEW_VR is different from VAR's previous
|
|
value.
|
|
|
|
NOTE: This function assumes that NEW_VR is a temporary value range
|
|
object created for the sole purpose of updating VAR's range. The
|
|
storage used by the equivalence set from NEW_VR will be freed by
|
|
this function. Do not call update_value_range when NEW_VR
|
|
is the range object associated with another SSA name. */
|
|
|
|
static inline bool
|
|
update_value_range (const_tree var, value_range_t *new_vr)
|
|
{
|
|
value_range_t *old_vr;
|
|
bool is_new;
|
|
|
|
/* Update the value range, if necessary. */
|
|
old_vr = get_value_range (var);
|
|
is_new = old_vr->type != new_vr->type
|
|
|| !vrp_operand_equal_p (old_vr->min, new_vr->min)
|
|
|| !vrp_operand_equal_p (old_vr->max, new_vr->max)
|
|
|| !vrp_bitmap_equal_p (old_vr->equiv, new_vr->equiv);
|
|
|
|
if (is_new)
|
|
{
|
|
/* Do not allow transitions up the lattice. The following
|
|
is slightly more awkward than just new_vr->type < old_vr->type
|
|
because VR_RANGE and VR_ANTI_RANGE need to be considered
|
|
the same. We may not have is_new when transitioning to
|
|
UNDEFINED or from VARYING. */
|
|
if (new_vr->type == VR_UNDEFINED
|
|
|| old_vr->type == VR_VARYING)
|
|
set_value_range_to_varying (old_vr);
|
|
else
|
|
set_value_range (old_vr, new_vr->type, new_vr->min, new_vr->max,
|
|
new_vr->equiv);
|
|
}
|
|
|
|
BITMAP_FREE (new_vr->equiv);
|
|
|
|
return is_new;
|
|
}
|
|
|
|
|
|
/* Add VAR and VAR's equivalence set to EQUIV. This is the central
|
|
point where equivalence processing can be turned on/off. */
|
|
|
|
static void
|
|
add_equivalence (bitmap *equiv, const_tree var)
|
|
{
|
|
unsigned ver = SSA_NAME_VERSION (var);
|
|
value_range_t *vr = vr_value[ver];
|
|
|
|
if (*equiv == NULL)
|
|
*equiv = BITMAP_ALLOC (NULL);
|
|
bitmap_set_bit (*equiv, ver);
|
|
if (vr && vr->equiv)
|
|
bitmap_ior_into (*equiv, vr->equiv);
|
|
}
|
|
|
|
|
|
/* Return true if VR is ~[0, 0]. */
|
|
|
|
static inline bool
|
|
range_is_nonnull (value_range_t *vr)
|
|
{
|
|
return vr->type == VR_ANTI_RANGE
|
|
&& integer_zerop (vr->min)
|
|
&& integer_zerop (vr->max);
|
|
}
|
|
|
|
|
|
/* Return true if VR is [0, 0]. */
|
|
|
|
static inline bool
|
|
range_is_null (value_range_t *vr)
|
|
{
|
|
return vr->type == VR_RANGE
|
|
&& integer_zerop (vr->min)
|
|
&& integer_zerop (vr->max);
|
|
}
|
|
|
|
/* Return true if max and min of VR are INTEGER_CST. It's not necessary
|
|
a singleton. */
|
|
|
|
static inline bool
|
|
range_int_cst_p (value_range_t *vr)
|
|
{
|
|
return (vr->type == VR_RANGE
|
|
&& TREE_CODE (vr->max) == INTEGER_CST
|
|
&& TREE_CODE (vr->min) == INTEGER_CST);
|
|
}
|
|
|
|
/* Return true if VR is a INTEGER_CST singleton. */
|
|
|
|
static inline bool
|
|
range_int_cst_singleton_p (value_range_t *vr)
|
|
{
|
|
return (range_int_cst_p (vr)
|
|
&& !TREE_OVERFLOW (vr->min)
|
|
&& !TREE_OVERFLOW (vr->max)
|
|
&& tree_int_cst_equal (vr->min, vr->max));
|
|
}
|
|
|
|
/* Return true if value range VR involves at least one symbol. */
|
|
|
|
static inline bool
|
|
symbolic_range_p (value_range_t *vr)
|
|
{
|
|
return (!is_gimple_min_invariant (vr->min)
|
|
|| !is_gimple_min_invariant (vr->max));
|
|
}
|
|
|
|
/* Return true if value range VR uses an overflow infinity. */
|
|
|
|
static inline bool
|
|
overflow_infinity_range_p (value_range_t *vr)
|
|
{
|
|
return (vr->type == VR_RANGE
|
|
&& (is_overflow_infinity (vr->min)
|
|
|| is_overflow_infinity (vr->max)));
|
|
}
|
|
|
|
/* Return false if we can not make a valid comparison based on VR;
|
|
this will be the case if it uses an overflow infinity and overflow
|
|
is not undefined (i.e., -fno-strict-overflow is in effect).
|
|
Otherwise return true, and set *STRICT_OVERFLOW_P to true if VR
|
|
uses an overflow infinity. */
|
|
|
|
static bool
|
|
usable_range_p (value_range_t *vr, bool *strict_overflow_p)
|
|
{
|
|
gcc_assert (vr->type == VR_RANGE);
|
|
if (is_overflow_infinity (vr->min))
|
|
{
|
|
*strict_overflow_p = true;
|
|
if (!TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (vr->min)))
|
|
return false;
|
|
}
|
|
if (is_overflow_infinity (vr->max))
|
|
{
|
|
*strict_overflow_p = true;
|
|
if (!TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (vr->max)))
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
|
|
/* Return true if the result of assignment STMT is know to be non-negative.
|
|
If the return value is based on the assumption that signed overflow is
|
|
undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't change
|
|
*STRICT_OVERFLOW_P.*/
|
|
|
|
static bool
|
|
gimple_assign_nonnegative_warnv_p (gimple stmt, bool *strict_overflow_p)
|
|
{
|
|
enum tree_code code = gimple_assign_rhs_code (stmt);
|
|
switch (get_gimple_rhs_class (code))
|
|
{
|
|
case GIMPLE_UNARY_RHS:
|
|
return tree_unary_nonnegative_warnv_p (gimple_assign_rhs_code (stmt),
|
|
gimple_expr_type (stmt),
|
|
gimple_assign_rhs1 (stmt),
|
|
strict_overflow_p);
|
|
case GIMPLE_BINARY_RHS:
|
|
return tree_binary_nonnegative_warnv_p (gimple_assign_rhs_code (stmt),
|
|
gimple_expr_type (stmt),
|
|
gimple_assign_rhs1 (stmt),
|
|
gimple_assign_rhs2 (stmt),
|
|
strict_overflow_p);
|
|
case GIMPLE_TERNARY_RHS:
|
|
return false;
|
|
case GIMPLE_SINGLE_RHS:
|
|
return tree_single_nonnegative_warnv_p (gimple_assign_rhs1 (stmt),
|
|
strict_overflow_p);
|
|
case GIMPLE_INVALID_RHS:
|
|
gcc_unreachable ();
|
|
default:
|
|
gcc_unreachable ();
|
|
}
|
|
}
|
|
|
|
/* Return true if return value of call STMT is know to be non-negative.
|
|
If the return value is based on the assumption that signed overflow is
|
|
undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't change
|
|
*STRICT_OVERFLOW_P.*/
|
|
|
|
static bool
|
|
gimple_call_nonnegative_warnv_p (gimple stmt, bool *strict_overflow_p)
|
|
{
|
|
tree arg0 = gimple_call_num_args (stmt) > 0 ?
|
|
gimple_call_arg (stmt, 0) : NULL_TREE;
|
|
tree arg1 = gimple_call_num_args (stmt) > 1 ?
|
|
gimple_call_arg (stmt, 1) : NULL_TREE;
|
|
|
|
return tree_call_nonnegative_warnv_p (gimple_expr_type (stmt),
|
|
gimple_call_fndecl (stmt),
|
|
arg0,
|
|
arg1,
|
|
strict_overflow_p);
|
|
}
|
|
|
|
/* Return true if STMT is know to to compute a non-negative value.
|
|
If the return value is based on the assumption that signed overflow is
|
|
undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't change
|
|
*STRICT_OVERFLOW_P.*/
|
|
|
|
static bool
|
|
gimple_stmt_nonnegative_warnv_p (gimple stmt, bool *strict_overflow_p)
|
|
{
|
|
switch (gimple_code (stmt))
|
|
{
|
|
case GIMPLE_ASSIGN:
|
|
return gimple_assign_nonnegative_warnv_p (stmt, strict_overflow_p);
|
|
case GIMPLE_CALL:
|
|
return gimple_call_nonnegative_warnv_p (stmt, strict_overflow_p);
|
|
default:
|
|
gcc_unreachable ();
|
|
}
|
|
}
|
|
|
|
/* Return true if the result of assignment STMT is know to be non-zero.
|
|
If the return value is based on the assumption that signed overflow is
|
|
undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't change
|
|
*STRICT_OVERFLOW_P.*/
|
|
|
|
static bool
|
|
gimple_assign_nonzero_warnv_p (gimple stmt, bool *strict_overflow_p)
|
|
{
|
|
enum tree_code code = gimple_assign_rhs_code (stmt);
|
|
switch (get_gimple_rhs_class (code))
|
|
{
|
|
case GIMPLE_UNARY_RHS:
|
|
return tree_unary_nonzero_warnv_p (gimple_assign_rhs_code (stmt),
|
|
gimple_expr_type (stmt),
|
|
gimple_assign_rhs1 (stmt),
|
|
strict_overflow_p);
|
|
case GIMPLE_BINARY_RHS:
|
|
return tree_binary_nonzero_warnv_p (gimple_assign_rhs_code (stmt),
|
|
gimple_expr_type (stmt),
|
|
gimple_assign_rhs1 (stmt),
|
|
gimple_assign_rhs2 (stmt),
|
|
strict_overflow_p);
|
|
case GIMPLE_TERNARY_RHS:
|
|
return false;
|
|
case GIMPLE_SINGLE_RHS:
|
|
return tree_single_nonzero_warnv_p (gimple_assign_rhs1 (stmt),
|
|
strict_overflow_p);
|
|
case GIMPLE_INVALID_RHS:
|
|
gcc_unreachable ();
|
|
default:
|
|
gcc_unreachable ();
|
|
}
|
|
}
|
|
|
|
/* Return true if STMT is know to to compute a non-zero value.
|
|
If the return value is based on the assumption that signed overflow is
|
|
undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't change
|
|
*STRICT_OVERFLOW_P.*/
|
|
|
|
static bool
|
|
gimple_stmt_nonzero_warnv_p (gimple stmt, bool *strict_overflow_p)
|
|
{
|
|
switch (gimple_code (stmt))
|
|
{
|
|
case GIMPLE_ASSIGN:
|
|
return gimple_assign_nonzero_warnv_p (stmt, strict_overflow_p);
|
|
case GIMPLE_CALL:
|
|
return gimple_alloca_call_p (stmt);
|
|
default:
|
|
gcc_unreachable ();
|
|
}
|
|
}
|
|
|
|
/* Like tree_expr_nonzero_warnv_p, but this function uses value ranges
|
|
obtained so far. */
|
|
|
|
static bool
|
|
vrp_stmt_computes_nonzero (gimple stmt, bool *strict_overflow_p)
|
|
{
|
|
if (gimple_stmt_nonzero_warnv_p (stmt, strict_overflow_p))
|
|
return true;
|
|
|
|
/* If we have an expression of the form &X->a, then the expression
|
|
is nonnull if X is nonnull. */
|
|
if (is_gimple_assign (stmt)
|
|
&& gimple_assign_rhs_code (stmt) == ADDR_EXPR)
|
|
{
|
|
tree expr = gimple_assign_rhs1 (stmt);
|
|
tree base = get_base_address (TREE_OPERAND (expr, 0));
|
|
|
|
if (base != NULL_TREE
|
|
&& TREE_CODE (base) == MEM_REF
|
|
&& TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME)
|
|
{
|
|
value_range_t *vr = get_value_range (TREE_OPERAND (base, 0));
|
|
if (range_is_nonnull (vr))
|
|
return true;
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/* Returns true if EXPR is a valid value (as expected by compare_values) --
|
|
a gimple invariant, or SSA_NAME +- CST. */
|
|
|
|
static bool
|
|
valid_value_p (tree expr)
|
|
{
|
|
if (TREE_CODE (expr) == SSA_NAME)
|
|
return true;
|
|
|
|
if (TREE_CODE (expr) == PLUS_EXPR
|
|
|| TREE_CODE (expr) == MINUS_EXPR)
|
|
return (TREE_CODE (TREE_OPERAND (expr, 0)) == SSA_NAME
|
|
&& TREE_CODE (TREE_OPERAND (expr, 1)) == INTEGER_CST);
|
|
|
|
return is_gimple_min_invariant (expr);
|
|
}
|
|
|
|
/* Return
|
|
1 if VAL < VAL2
|
|
0 if !(VAL < VAL2)
|
|
-2 if those are incomparable. */
|
|
static inline int
|
|
operand_less_p (tree val, tree val2)
|
|
{
|
|
/* LT is folded faster than GE and others. Inline the common case. */
|
|
if (TREE_CODE (val) == INTEGER_CST && TREE_CODE (val2) == INTEGER_CST)
|
|
{
|
|
if (TYPE_UNSIGNED (TREE_TYPE (val)))
|
|
return INT_CST_LT_UNSIGNED (val, val2);
|
|
else
|
|
{
|
|
if (INT_CST_LT (val, val2))
|
|
return 1;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
tree tcmp;
|
|
|
|
fold_defer_overflow_warnings ();
|
|
|
|
tcmp = fold_binary_to_constant (LT_EXPR, boolean_type_node, val, val2);
|
|
|
|
fold_undefer_and_ignore_overflow_warnings ();
|
|
|
|
if (!tcmp
|
|
|| TREE_CODE (tcmp) != INTEGER_CST)
|
|
return -2;
|
|
|
|
if (!integer_zerop (tcmp))
|
|
return 1;
|
|
}
|
|
|
|
/* val >= val2, not considering overflow infinity. */
|
|
if (is_negative_overflow_infinity (val))
|
|
return is_negative_overflow_infinity (val2) ? 0 : 1;
|
|
else if (is_positive_overflow_infinity (val2))
|
|
return is_positive_overflow_infinity (val) ? 0 : 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Compare two values VAL1 and VAL2. Return
|
|
|
|
-2 if VAL1 and VAL2 cannot be compared at compile-time,
|
|
-1 if VAL1 < VAL2,
|
|
0 if VAL1 == VAL2,
|
|
+1 if VAL1 > VAL2, and
|
|
+2 if VAL1 != VAL2
|
|
|
|
This is similar to tree_int_cst_compare but supports pointer values
|
|
and values that cannot be compared at compile time.
|
|
|
|
If STRICT_OVERFLOW_P is not NULL, then set *STRICT_OVERFLOW_P to
|
|
true if the return value is only valid if we assume that signed
|
|
overflow is undefined. */
|
|
|
|
static int
|
|
compare_values_warnv (tree val1, tree val2, bool *strict_overflow_p)
|
|
{
|
|
if (val1 == val2)
|
|
return 0;
|
|
|
|
/* Below we rely on the fact that VAL1 and VAL2 are both pointers or
|
|
both integers. */
|
|
gcc_assert (POINTER_TYPE_P (TREE_TYPE (val1))
|
|
== POINTER_TYPE_P (TREE_TYPE (val2)));
|
|
/* Convert the two values into the same type. This is needed because
|
|
sizetype causes sign extension even for unsigned types. */
|
|
val2 = fold_convert (TREE_TYPE (val1), val2);
|
|
STRIP_USELESS_TYPE_CONVERSION (val2);
|
|
|
|
if ((TREE_CODE (val1) == SSA_NAME
|
|
|| TREE_CODE (val1) == PLUS_EXPR
|
|
|| TREE_CODE (val1) == MINUS_EXPR)
|
|
&& (TREE_CODE (val2) == SSA_NAME
|
|
|| TREE_CODE (val2) == PLUS_EXPR
|
|
|| TREE_CODE (val2) == MINUS_EXPR))
|
|
{
|
|
tree n1, c1, n2, c2;
|
|
enum tree_code code1, code2;
|
|
|
|
/* If VAL1 and VAL2 are of the form 'NAME [+-] CST' or 'NAME',
|
|
return -1 or +1 accordingly. If VAL1 and VAL2 don't use the
|
|
same name, return -2. */
|
|
if (TREE_CODE (val1) == SSA_NAME)
|
|
{
|
|
code1 = SSA_NAME;
|
|
n1 = val1;
|
|
c1 = NULL_TREE;
|
|
}
|
|
else
|
|
{
|
|
code1 = TREE_CODE (val1);
|
|
n1 = TREE_OPERAND (val1, 0);
|
|
c1 = TREE_OPERAND (val1, 1);
|
|
if (tree_int_cst_sgn (c1) == -1)
|
|
{
|
|
if (is_negative_overflow_infinity (c1))
|
|
return -2;
|
|
c1 = fold_unary_to_constant (NEGATE_EXPR, TREE_TYPE (c1), c1);
|
|
if (!c1)
|
|
return -2;
|
|
code1 = code1 == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR;
|
|
}
|
|
}
|
|
|
|
if (TREE_CODE (val2) == SSA_NAME)
|
|
{
|
|
code2 = SSA_NAME;
|
|
n2 = val2;
|
|
c2 = NULL_TREE;
|
|
}
|
|
else
|
|
{
|
|
code2 = TREE_CODE (val2);
|
|
n2 = TREE_OPERAND (val2, 0);
|
|
c2 = TREE_OPERAND (val2, 1);
|
|
if (tree_int_cst_sgn (c2) == -1)
|
|
{
|
|
if (is_negative_overflow_infinity (c2))
|
|
return -2;
|
|
c2 = fold_unary_to_constant (NEGATE_EXPR, TREE_TYPE (c2), c2);
|
|
if (!c2)
|
|
return -2;
|
|
code2 = code2 == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR;
|
|
}
|
|
}
|
|
|
|
/* Both values must use the same name. */
|
|
if (n1 != n2)
|
|
return -2;
|
|
|
|
if (code1 == SSA_NAME
|
|
&& code2 == SSA_NAME)
|
|
/* NAME == NAME */
|
|
return 0;
|
|
|
|
/* If overflow is defined we cannot simplify more. */
|
|
if (!TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (val1)))
|
|
return -2;
|
|
|
|
if (strict_overflow_p != NULL
|
|
&& (code1 == SSA_NAME || !TREE_NO_WARNING (val1))
|
|
&& (code2 == SSA_NAME || !TREE_NO_WARNING (val2)))
|
|
*strict_overflow_p = true;
|
|
|
|
if (code1 == SSA_NAME)
|
|
{
|
|
if (code2 == PLUS_EXPR)
|
|
/* NAME < NAME + CST */
|
|
return -1;
|
|
else if (code2 == MINUS_EXPR)
|
|
/* NAME > NAME - CST */
|
|
return 1;
|
|
}
|
|
else if (code1 == PLUS_EXPR)
|
|
{
|
|
if (code2 == SSA_NAME)
|
|
/* NAME + CST > NAME */
|
|
return 1;
|
|
else if (code2 == PLUS_EXPR)
|
|
/* NAME + CST1 > NAME + CST2, if CST1 > CST2 */
|
|
return compare_values_warnv (c1, c2, strict_overflow_p);
|
|
else if (code2 == MINUS_EXPR)
|
|
/* NAME + CST1 > NAME - CST2 */
|
|
return 1;
|
|
}
|
|
else if (code1 == MINUS_EXPR)
|
|
{
|
|
if (code2 == SSA_NAME)
|
|
/* NAME - CST < NAME */
|
|
return -1;
|
|
else if (code2 == PLUS_EXPR)
|
|
/* NAME - CST1 < NAME + CST2 */
|
|
return -1;
|
|
else if (code2 == MINUS_EXPR)
|
|
/* NAME - CST1 > NAME - CST2, if CST1 < CST2. Notice that
|
|
C1 and C2 are swapped in the call to compare_values. */
|
|
return compare_values_warnv (c2, c1, strict_overflow_p);
|
|
}
|
|
|
|
gcc_unreachable ();
|
|
}
|
|
|
|
/* We cannot compare non-constants. */
|
|
if (!is_gimple_min_invariant (val1) || !is_gimple_min_invariant (val2))
|
|
return -2;
|
|
|
|
if (!POINTER_TYPE_P (TREE_TYPE (val1)))
|
|
{
|
|
/* We cannot compare overflowed values, except for overflow
|
|
infinities. */
|
|
if (TREE_OVERFLOW (val1) || TREE_OVERFLOW (val2))
|
|
{
|
|
if (strict_overflow_p != NULL)
|
|
*strict_overflow_p = true;
|
|
if (is_negative_overflow_infinity (val1))
|
|
return is_negative_overflow_infinity (val2) ? 0 : -1;
|
|
else if (is_negative_overflow_infinity (val2))
|
|
return 1;
|
|
else if (is_positive_overflow_infinity (val1))
|
|
return is_positive_overflow_infinity (val2) ? 0 : 1;
|
|
else if (is_positive_overflow_infinity (val2))
|
|
return -1;
|
|
return -2;
|
|
}
|
|
|
|
return tree_int_cst_compare (val1, val2);
|
|
}
|
|
else
|
|
{
|
|
tree t;
|
|
|
|
/* First see if VAL1 and VAL2 are not the same. */
|
|
if (val1 == val2 || operand_equal_p (val1, val2, 0))
|
|
return 0;
|
|
|
|
/* If VAL1 is a lower address than VAL2, return -1. */
|
|
if (operand_less_p (val1, val2) == 1)
|
|
return -1;
|
|
|
|
/* If VAL1 is a higher address than VAL2, return +1. */
|
|
if (operand_less_p (val2, val1) == 1)
|
|
return 1;
|
|
|
|
/* If VAL1 is different than VAL2, return +2.
|
|
For integer constants we either have already returned -1 or 1
|
|
or they are equivalent. We still might succeed in proving
|
|
something about non-trivial operands. */
|
|
if (TREE_CODE (val1) != INTEGER_CST
|
|
|| TREE_CODE (val2) != INTEGER_CST)
|
|
{
|
|
t = fold_binary_to_constant (NE_EXPR, boolean_type_node, val1, val2);
|
|
if (t && integer_onep (t))
|
|
return 2;
|
|
}
|
|
|
|
return -2;
|
|
}
|
|
}
|
|
|
|
/* Compare values like compare_values_warnv, but treat comparisons of
|
|
nonconstants which rely on undefined overflow as incomparable. */
|
|
|
|
static int
|
|
compare_values (tree val1, tree val2)
|
|
{
|
|
bool sop;
|
|
int ret;
|
|
|
|
sop = false;
|
|
ret = compare_values_warnv (val1, val2, &sop);
|
|
if (sop
|
|
&& (!is_gimple_min_invariant (val1) || !is_gimple_min_invariant (val2)))
|
|
ret = -2;
|
|
return ret;
|
|
}
|
|
|
|
|
|
/* Return 1 if VAL is inside value range MIN <= VAL <= MAX,
|
|
0 if VAL is not inside [MIN, MAX],
|
|
-2 if we cannot tell either way.
|
|
|
|
Benchmark compile/20001226-1.c compilation time after changing this
|
|
function. */
|
|
|
|
static inline int
|
|
value_inside_range (tree val, tree min, tree max)
|
|
{
|
|
int cmp1, cmp2;
|
|
|
|
cmp1 = operand_less_p (val, min);
|
|
if (cmp1 == -2)
|
|
return -2;
|
|
if (cmp1 == 1)
|
|
return 0;
|
|
|
|
cmp2 = operand_less_p (max, val);
|
|
if (cmp2 == -2)
|
|
return -2;
|
|
|
|
return !cmp2;
|
|
}
|
|
|
|
|
|
/* Return true if value ranges VR0 and VR1 have a non-empty
|
|
intersection.
|
|
|
|
Benchmark compile/20001226-1.c compilation time after changing this
|
|
function.
|
|
*/
|
|
|
|
static inline bool
|
|
value_ranges_intersect_p (value_range_t *vr0, value_range_t *vr1)
|
|
{
|
|
/* The value ranges do not intersect if the maximum of the first range is
|
|
less than the minimum of the second range or vice versa.
|
|
When those relations are unknown, we can't do any better. */
|
|
if (operand_less_p (vr0->max, vr1->min) != 0)
|
|
return false;
|
|
if (operand_less_p (vr1->max, vr0->min) != 0)
|
|
return false;
|
|
return true;
|
|
}
|
|
|
|
|
|
/* Return 1 if [MIN, MAX] includes the value zero, 0 if it does not
|
|
include the value zero, -2 if we cannot tell. */
|
|
|
|
static inline int
|
|
range_includes_zero_p (tree min, tree max)
|
|
{
|
|
tree zero = build_int_cst (TREE_TYPE (min), 0);
|
|
return value_inside_range (zero, min, max);
|
|
}
|
|
|
|
/* Return true if *VR is know to only contain nonnegative values. */
|
|
|
|
static inline bool
|
|
value_range_nonnegative_p (value_range_t *vr)
|
|
{
|
|
/* Testing for VR_ANTI_RANGE is not useful here as any anti-range
|
|
which would return a useful value should be encoded as a
|
|
VR_RANGE. */
|
|
if (vr->type == VR_RANGE)
|
|
{
|
|
int result = compare_values (vr->min, integer_zero_node);
|
|
return (result == 0 || result == 1);
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/* Return true if T, an SSA_NAME, is known to be nonnegative. Return
|
|
false otherwise or if no value range information is available. */
|
|
|
|
bool
|
|
ssa_name_nonnegative_p (const_tree t)
|
|
{
|
|
value_range_t *vr = get_value_range (t);
|
|
|
|
if (INTEGRAL_TYPE_P (t)
|
|
&& TYPE_UNSIGNED (t))
|
|
return true;
|
|
|
|
if (!vr)
|
|
return false;
|
|
|
|
return value_range_nonnegative_p (vr);
|
|
}
|
|
|
|
/* If *VR has a value rante that is a single constant value return that,
|
|
otherwise return NULL_TREE. */
|
|
|
|
static tree
|
|
value_range_constant_singleton (value_range_t *vr)
|
|
{
|
|
if (vr->type == VR_RANGE
|
|
&& operand_equal_p (vr->min, vr->max, 0)
|
|
&& is_gimple_min_invariant (vr->min))
|
|
return vr->min;
|
|
|
|
return NULL_TREE;
|
|
}
|
|
|
|
/* If OP has a value range with a single constant value return that,
|
|
otherwise return NULL_TREE. This returns OP itself if OP is a
|
|
constant. */
|
|
|
|
static tree
|
|
op_with_constant_singleton_value_range (tree op)
|
|
{
|
|
if (is_gimple_min_invariant (op))
|
|
return op;
|
|
|
|
if (TREE_CODE (op) != SSA_NAME)
|
|
return NULL_TREE;
|
|
|
|
return value_range_constant_singleton (get_value_range (op));
|
|
}
|
|
|
|
/* Return true if op is in a boolean [0, 1] value-range. */
|
|
|
|
static bool
|
|
op_with_boolean_value_range_p (tree op)
|
|
{
|
|
value_range_t *vr;
|
|
|
|
if (TYPE_PRECISION (TREE_TYPE (op)) == 1)
|
|
return true;
|
|
|
|
if (integer_zerop (op)
|
|
|| integer_onep (op))
|
|
return true;
|
|
|
|
if (TREE_CODE (op) != SSA_NAME)
|
|
return false;
|
|
|
|
vr = get_value_range (op);
|
|
return (vr->type == VR_RANGE
|
|
&& integer_zerop (vr->min)
|
|
&& integer_onep (vr->max));
|
|
}
|
|
|
|
/* Extract value range information from an ASSERT_EXPR EXPR and store
|
|
it in *VR_P. */
|
|
|
|
static void
|
|
extract_range_from_assert (value_range_t *vr_p, tree expr)
|
|
{
|
|
tree var, cond, limit, min, max, type;
|
|
value_range_t *limit_vr;
|
|
enum tree_code cond_code;
|
|
|
|
var = ASSERT_EXPR_VAR (expr);
|
|
cond = ASSERT_EXPR_COND (expr);
|
|
|
|
gcc_assert (COMPARISON_CLASS_P (cond));
|
|
|
|
/* Find VAR in the ASSERT_EXPR conditional. */
|
|
if (var == TREE_OPERAND (cond, 0)
|
|
|| TREE_CODE (TREE_OPERAND (cond, 0)) == PLUS_EXPR
|
|
|| TREE_CODE (TREE_OPERAND (cond, 0)) == NOP_EXPR)
|
|
{
|
|
/* If the predicate is of the form VAR COMP LIMIT, then we just
|
|
take LIMIT from the RHS and use the same comparison code. */
|
|
cond_code = TREE_CODE (cond);
|
|
limit = TREE_OPERAND (cond, 1);
|
|
cond = TREE_OPERAND (cond, 0);
|
|
}
|
|
else
|
|
{
|
|
/* If the predicate is of the form LIMIT COMP VAR, then we need
|
|
to flip around the comparison code to create the proper range
|
|
for VAR. */
|
|
cond_code = swap_tree_comparison (TREE_CODE (cond));
|
|
limit = TREE_OPERAND (cond, 0);
|
|
cond = TREE_OPERAND (cond, 1);
|
|
}
|
|
|
|
limit = avoid_overflow_infinity (limit);
|
|
|
|
type = TREE_TYPE (var);
|
|
gcc_assert (limit != var);
|
|
|
|
/* For pointer arithmetic, we only keep track of pointer equality
|
|
and inequality. */
|
|
if (POINTER_TYPE_P (type) && cond_code != NE_EXPR && cond_code != EQ_EXPR)
|
|
{
|
|
set_value_range_to_varying (vr_p);
|
|
return;
|
|
}
|
|
|
|
/* If LIMIT is another SSA name and LIMIT has a range of its own,
|
|
try to use LIMIT's range to avoid creating symbolic ranges
|
|
unnecessarily. */
|
|
limit_vr = (TREE_CODE (limit) == SSA_NAME) ? get_value_range (limit) : NULL;
|
|
|
|
/* LIMIT's range is only interesting if it has any useful information. */
|
|
if (limit_vr
|
|
&& (limit_vr->type == VR_UNDEFINED
|
|
|| limit_vr->type == VR_VARYING
|
|
|| symbolic_range_p (limit_vr)))
|
|
limit_vr = NULL;
|
|
|
|
/* Initially, the new range has the same set of equivalences of
|
|
VAR's range. This will be revised before returning the final
|
|
value. Since assertions may be chained via mutually exclusive
|
|
predicates, we will need to trim the set of equivalences before
|
|
we are done. */
|
|
gcc_assert (vr_p->equiv == NULL);
|
|
add_equivalence (&vr_p->equiv, var);
|
|
|
|
/* Extract a new range based on the asserted comparison for VAR and
|
|
LIMIT's value range. Notice that if LIMIT has an anti-range, we
|
|
will only use it for equality comparisons (EQ_EXPR). For any
|
|
other kind of assertion, we cannot derive a range from LIMIT's
|
|
anti-range that can be used to describe the new range. For
|
|
instance, ASSERT_EXPR <x_2, x_2 <= b_4>. If b_4 is ~[2, 10],
|
|
then b_4 takes on the ranges [-INF, 1] and [11, +INF]. There is
|
|
no single range for x_2 that could describe LE_EXPR, so we might
|
|
as well build the range [b_4, +INF] for it.
|
|
One special case we handle is extracting a range from a
|
|
range test encoded as (unsigned)var + CST <= limit. */
|
|
if (TREE_CODE (cond) == NOP_EXPR
|
|
|| TREE_CODE (cond) == PLUS_EXPR)
|
|
{
|
|
if (TREE_CODE (cond) == PLUS_EXPR)
|
|
{
|
|
min = fold_build1 (NEGATE_EXPR, TREE_TYPE (TREE_OPERAND (cond, 1)),
|
|
TREE_OPERAND (cond, 1));
|
|
max = int_const_binop (PLUS_EXPR, limit, min);
|
|
cond = TREE_OPERAND (cond, 0);
|
|
}
|
|
else
|
|
{
|
|
min = build_int_cst (TREE_TYPE (var), 0);
|
|
max = limit;
|
|
}
|
|
|
|
/* Make sure to not set TREE_OVERFLOW on the final type
|
|
conversion. We are willingly interpreting large positive
|
|
unsigned values as negative singed values here. */
|
|
min = force_fit_type_double (TREE_TYPE (var), tree_to_double_int (min),
|
|
0, false);
|
|
max = force_fit_type_double (TREE_TYPE (var), tree_to_double_int (max),
|
|
0, false);
|
|
|
|
/* We can transform a max, min range to an anti-range or
|
|
vice-versa. Use set_and_canonicalize_value_range which does
|
|
this for us. */
|
|
if (cond_code == LE_EXPR)
|
|
set_and_canonicalize_value_range (vr_p, VR_RANGE,
|
|
min, max, vr_p->equiv);
|
|
else if (cond_code == GT_EXPR)
|
|
set_and_canonicalize_value_range (vr_p, VR_ANTI_RANGE,
|
|
min, max, vr_p->equiv);
|
|
else
|
|
gcc_unreachable ();
|
|
}
|
|
else if (cond_code == EQ_EXPR)
|
|
{
|
|
enum value_range_type range_type;
|
|
|
|
if (limit_vr)
|
|
{
|
|
range_type = limit_vr->type;
|
|
min = limit_vr->min;
|
|
max = limit_vr->max;
|
|
}
|
|
else
|
|
{
|
|
range_type = VR_RANGE;
|
|
min = limit;
|
|
max = limit;
|
|
}
|
|
|
|
set_value_range (vr_p, range_type, min, max, vr_p->equiv);
|
|
|
|
/* When asserting the equality VAR == LIMIT and LIMIT is another
|
|
SSA name, the new range will also inherit the equivalence set
|
|
from LIMIT. */
|
|
if (TREE_CODE (limit) == SSA_NAME)
|
|
add_equivalence (&vr_p->equiv, limit);
|
|
}
|
|
else if (cond_code == NE_EXPR)
|
|
{
|
|
/* As described above, when LIMIT's range is an anti-range and
|
|
this assertion is an inequality (NE_EXPR), then we cannot
|
|
derive anything from the anti-range. For instance, if
|
|
LIMIT's range was ~[0, 0], the assertion 'VAR != LIMIT' does
|
|
not imply that VAR's range is [0, 0]. So, in the case of
|
|
anti-ranges, we just assert the inequality using LIMIT and
|
|
not its anti-range.
|
|
|
|
If LIMIT_VR is a range, we can only use it to build a new
|
|
anti-range if LIMIT_VR is a single-valued range. For
|
|
instance, if LIMIT_VR is [0, 1], the predicate
|
|
VAR != [0, 1] does not mean that VAR's range is ~[0, 1].
|
|
Rather, it means that for value 0 VAR should be ~[0, 0]
|
|
and for value 1, VAR should be ~[1, 1]. We cannot
|
|
represent these ranges.
|
|
|
|
The only situation in which we can build a valid
|
|
anti-range is when LIMIT_VR is a single-valued range
|
|
(i.e., LIMIT_VR->MIN == LIMIT_VR->MAX). In that case,
|
|
build the anti-range ~[LIMIT_VR->MIN, LIMIT_VR->MAX]. */
|
|
if (limit_vr
|
|
&& limit_vr->type == VR_RANGE
|
|
&& compare_values (limit_vr->min, limit_vr->max) == 0)
|
|
{
|
|
min = limit_vr->min;
|
|
max = limit_vr->max;
|
|
}
|
|
else
|
|
{
|
|
/* In any other case, we cannot use LIMIT's range to build a
|
|
valid anti-range. */
|
|
min = max = limit;
|
|
}
|
|
|
|
/* If MIN and MAX cover the whole range for their type, then
|
|
just use the original LIMIT. */
|
|
if (INTEGRAL_TYPE_P (type)
|
|
&& vrp_val_is_min (min)
|
|
&& vrp_val_is_max (max))
|
|
min = max = limit;
|
|
|
|
set_and_canonicalize_value_range (vr_p, VR_ANTI_RANGE,
|
|
min, max, vr_p->equiv);
|
|
}
|
|
else if (cond_code == LE_EXPR || cond_code == LT_EXPR)
|
|
{
|
|
min = TYPE_MIN_VALUE (type);
|
|
|
|
if (limit_vr == NULL || limit_vr->type == VR_ANTI_RANGE)
|
|
max = limit;
|
|
else
|
|
{
|
|
/* If LIMIT_VR is of the form [N1, N2], we need to build the
|
|
range [MIN, N2] for LE_EXPR and [MIN, N2 - 1] for
|
|
LT_EXPR. */
|
|
max = limit_vr->max;
|
|
}
|
|
|
|
/* If the maximum value forces us to be out of bounds, simply punt.
|
|
It would be pointless to try and do anything more since this
|
|
all should be optimized away above us. */
|
|
if ((cond_code == LT_EXPR
|
|
&& compare_values (max, min) == 0)
|
|
|| (CONSTANT_CLASS_P (max) && TREE_OVERFLOW (max)))
|
|
set_value_range_to_varying (vr_p);
|
|
else
|
|
{
|
|
/* For LT_EXPR, we create the range [MIN, MAX - 1]. */
|
|
if (cond_code == LT_EXPR)
|
|
{
|
|
if (TYPE_PRECISION (TREE_TYPE (max)) == 1
|
|
&& !TYPE_UNSIGNED (TREE_TYPE (max)))
|
|
max = fold_build2 (PLUS_EXPR, TREE_TYPE (max), max,
|
|
build_int_cst (TREE_TYPE (max), -1));
|
|
else
|
|
max = fold_build2 (MINUS_EXPR, TREE_TYPE (max), max,
|
|
build_int_cst (TREE_TYPE (max), 1));
|
|
if (EXPR_P (max))
|
|
TREE_NO_WARNING (max) = 1;
|
|
}
|
|
|
|
set_value_range (vr_p, VR_RANGE, min, max, vr_p->equiv);
|
|
}
|
|
}
|
|
else if (cond_code == GE_EXPR || cond_code == GT_EXPR)
|
|
{
|
|
max = TYPE_MAX_VALUE (type);
|
|
|
|
if (limit_vr == NULL || limit_vr->type == VR_ANTI_RANGE)
|
|
min = limit;
|
|
else
|
|
{
|
|
/* If LIMIT_VR is of the form [N1, N2], we need to build the
|
|
range [N1, MAX] for GE_EXPR and [N1 + 1, MAX] for
|
|
GT_EXPR. */
|
|
min = limit_vr->min;
|
|
}
|
|
|
|
/* If the minimum value forces us to be out of bounds, simply punt.
|
|
It would be pointless to try and do anything more since this
|
|
all should be optimized away above us. */
|
|
if ((cond_code == GT_EXPR
|
|
&& compare_values (min, max) == 0)
|
|
|| (CONSTANT_CLASS_P (min) && TREE_OVERFLOW (min)))
|
|
set_value_range_to_varying (vr_p);
|
|
else
|
|
{
|
|
/* For GT_EXPR, we create the range [MIN + 1, MAX]. */
|
|
if (cond_code == GT_EXPR)
|
|
{
|
|
if (TYPE_PRECISION (TREE_TYPE (min)) == 1
|
|
&& !TYPE_UNSIGNED (TREE_TYPE (min)))
|
|
min = fold_build2 (MINUS_EXPR, TREE_TYPE (min), min,
|
|
build_int_cst (TREE_TYPE (min), -1));
|
|
else
|
|
min = fold_build2 (PLUS_EXPR, TREE_TYPE (min), min,
|
|
build_int_cst (TREE_TYPE (min), 1));
|
|
if (EXPR_P (min))
|
|
TREE_NO_WARNING (min) = 1;
|
|
}
|
|
|
|
set_value_range (vr_p, VR_RANGE, min, max, vr_p->equiv);
|
|
}
|
|
}
|
|
else
|
|
gcc_unreachable ();
|
|
|
|
/* Finally intersect the new range with what we already know about var. */
|
|
vrp_intersect_ranges (vr_p, get_value_range (var));
|
|
}
|
|
|
|
|
|
/* Extract range information from SSA name VAR and store it in VR. If
|
|
VAR has an interesting range, use it. Otherwise, create the
|
|
range [VAR, VAR] and return it. This is useful in situations where
|
|
we may have conditionals testing values of VARYING names. For
|
|
instance,
|
|
|
|
x_3 = y_5;
|
|
if (x_3 > y_5)
|
|
...
|
|
|
|
Even if y_5 is deemed VARYING, we can determine that x_3 > y_5 is
|
|
always false. */
|
|
|
|
static void
|
|
extract_range_from_ssa_name (value_range_t *vr, tree var)
|
|
{
|
|
value_range_t *var_vr = get_value_range (var);
|
|
|
|
if (var_vr->type != VR_UNDEFINED && var_vr->type != VR_VARYING)
|
|
copy_value_range (vr, var_vr);
|
|
else
|
|
set_value_range (vr, VR_RANGE, var, var, NULL);
|
|
|
|
add_equivalence (&vr->equiv, var);
|
|
}
|
|
|
|
|
|
/* Wrapper around int_const_binop. If the operation overflows and we
|
|
are not using wrapping arithmetic, then adjust the result to be
|
|
-INF or +INF depending on CODE, VAL1 and VAL2. This can return
|
|
NULL_TREE if we need to use an overflow infinity representation but
|
|
the type does not support it. */
|
|
|
|
static tree
|
|
vrp_int_const_binop (enum tree_code code, tree val1, tree val2)
|
|
{
|
|
tree res;
|
|
|
|
res = int_const_binop (code, val1, val2);
|
|
|
|
/* If we are using unsigned arithmetic, operate symbolically
|
|
on -INF and +INF as int_const_binop only handles signed overflow. */
|
|
if (TYPE_UNSIGNED (TREE_TYPE (val1)))
|
|
{
|
|
int checkz = compare_values (res, val1);
|
|
bool overflow = false;
|
|
|
|
/* Ensure that res = val1 [+*] val2 >= val1
|
|
or that res = val1 - val2 <= val1. */
|
|
if ((code == PLUS_EXPR
|
|
&& !(checkz == 1 || checkz == 0))
|
|
|| (code == MINUS_EXPR
|
|
&& !(checkz == 0 || checkz == -1)))
|
|
{
|
|
overflow = true;
|
|
}
|
|
/* Checking for multiplication overflow is done by dividing the
|
|
output of the multiplication by the first input of the
|
|
multiplication. If the result of that division operation is
|
|
not equal to the second input of the multiplication, then the
|
|
multiplication overflowed. */
|
|
else if (code == MULT_EXPR && !integer_zerop (val1))
|
|
{
|
|
tree tmp = int_const_binop (TRUNC_DIV_EXPR,
|
|
res,
|
|
val1);
|
|
int check = compare_values (tmp, val2);
|
|
|
|
if (check != 0)
|
|
overflow = true;
|
|
}
|
|
|
|
if (overflow)
|
|
{
|
|
res = copy_node (res);
|
|
TREE_OVERFLOW (res) = 1;
|
|
}
|
|
|
|
}
|
|
else if (TYPE_OVERFLOW_WRAPS (TREE_TYPE (val1)))
|
|
/* If the singed operation wraps then int_const_binop has done
|
|
everything we want. */
|
|
;
|
|
else if ((TREE_OVERFLOW (res)
|
|
&& !TREE_OVERFLOW (val1)
|
|
&& !TREE_OVERFLOW (val2))
|
|
|| is_overflow_infinity (val1)
|
|
|| is_overflow_infinity (val2))
|
|
{
|
|
/* If the operation overflowed but neither VAL1 nor VAL2 are
|
|
overflown, return -INF or +INF depending on the operation
|
|
and the combination of signs of the operands. */
|
|
int sgn1 = tree_int_cst_sgn (val1);
|
|
int sgn2 = tree_int_cst_sgn (val2);
|
|
|
|
if (needs_overflow_infinity (TREE_TYPE (res))
|
|
&& !supports_overflow_infinity (TREE_TYPE (res)))
|
|
return NULL_TREE;
|
|
|
|
/* We have to punt on adding infinities of different signs,
|
|
since we can't tell what the sign of the result should be.
|
|
Likewise for subtracting infinities of the same sign. */
|
|
if (((code == PLUS_EXPR && sgn1 != sgn2)
|
|
|| (code == MINUS_EXPR && sgn1 == sgn2))
|
|
&& is_overflow_infinity (val1)
|
|
&& is_overflow_infinity (val2))
|
|
return NULL_TREE;
|
|
|
|
/* Don't try to handle division or shifting of infinities. */
|
|
if ((code == TRUNC_DIV_EXPR
|
|
|| code == FLOOR_DIV_EXPR
|
|
|| code == CEIL_DIV_EXPR
|
|
|| code == EXACT_DIV_EXPR
|
|
|| code == ROUND_DIV_EXPR
|
|
|| code == RSHIFT_EXPR)
|
|
&& (is_overflow_infinity (val1)
|
|
|| is_overflow_infinity (val2)))
|
|
return NULL_TREE;
|
|
|
|
/* Notice that we only need to handle the restricted set of
|
|
operations handled by extract_range_from_binary_expr.
|
|
Among them, only multiplication, addition and subtraction
|
|
can yield overflow without overflown operands because we
|
|
are working with integral types only... except in the
|
|
case VAL1 = -INF and VAL2 = -1 which overflows to +INF
|
|
for division too. */
|
|
|
|
/* For multiplication, the sign of the overflow is given
|
|
by the comparison of the signs of the operands. */
|
|
if ((code == MULT_EXPR && sgn1 == sgn2)
|
|
/* For addition, the operands must be of the same sign
|
|
to yield an overflow. Its sign is therefore that
|
|
of one of the operands, for example the first. For
|
|
infinite operands X + -INF is negative, not positive. */
|
|
|| (code == PLUS_EXPR
|
|
&& (sgn1 >= 0
|
|
? !is_negative_overflow_infinity (val2)
|
|
: is_positive_overflow_infinity (val2)))
|
|
/* For subtraction, non-infinite operands must be of
|
|
different signs to yield an overflow. Its sign is
|
|
therefore that of the first operand or the opposite of
|
|
that of the second operand. A first operand of 0 counts
|
|
as positive here, for the corner case 0 - (-INF), which
|
|
overflows, but must yield +INF. For infinite operands 0
|
|
- INF is negative, not positive. */
|
|
|| (code == MINUS_EXPR
|
|
&& (sgn1 >= 0
|
|
? !is_positive_overflow_infinity (val2)
|
|
: is_negative_overflow_infinity (val2)))
|
|
/* We only get in here with positive shift count, so the
|
|
overflow direction is the same as the sign of val1.
|
|
Actually rshift does not overflow at all, but we only
|
|
handle the case of shifting overflowed -INF and +INF. */
|
|
|| (code == RSHIFT_EXPR
|
|
&& sgn1 >= 0)
|
|
/* For division, the only case is -INF / -1 = +INF. */
|
|
|| code == TRUNC_DIV_EXPR
|
|
|| code == FLOOR_DIV_EXPR
|
|
|| code == CEIL_DIV_EXPR
|
|
|| code == EXACT_DIV_EXPR
|
|
|| code == ROUND_DIV_EXPR)
|
|
return (needs_overflow_infinity (TREE_TYPE (res))
|
|
? positive_overflow_infinity (TREE_TYPE (res))
|
|
: TYPE_MAX_VALUE (TREE_TYPE (res)));
|
|
else
|
|
return (needs_overflow_infinity (TREE_TYPE (res))
|
|
? negative_overflow_infinity (TREE_TYPE (res))
|
|
: TYPE_MIN_VALUE (TREE_TYPE (res)));
|
|
}
|
|
|
|
return res;
|
|
}
|
|
|
|
|
|
/* For range VR compute two double_int bitmasks. In *MAY_BE_NONZERO
|
|
bitmask if some bit is unset, it means for all numbers in the range
|
|
the bit is 0, otherwise it might be 0 or 1. In *MUST_BE_NONZERO
|
|
bitmask if some bit is set, it means for all numbers in the range
|
|
the bit is 1, otherwise it might be 0 or 1. */
|
|
|
|
static bool
|
|
zero_nonzero_bits_from_vr (value_range_t *vr,
|
|
double_int *may_be_nonzero,
|
|
double_int *must_be_nonzero)
|
|
{
|
|
*may_be_nonzero = double_int_minus_one;
|
|
*must_be_nonzero = double_int_zero;
|
|
if (!range_int_cst_p (vr)
|
|
|| TREE_OVERFLOW (vr->min)
|
|
|| TREE_OVERFLOW (vr->max))
|
|
return false;
|
|
|
|
if (range_int_cst_singleton_p (vr))
|
|
{
|
|
*may_be_nonzero = tree_to_double_int (vr->min);
|
|
*must_be_nonzero = *may_be_nonzero;
|
|
}
|
|
else if (tree_int_cst_sgn (vr->min) >= 0
|
|
|| tree_int_cst_sgn (vr->max) < 0)
|
|
{
|
|
double_int dmin = tree_to_double_int (vr->min);
|
|
double_int dmax = tree_to_double_int (vr->max);
|
|
double_int xor_mask = dmin ^ dmax;
|
|
*may_be_nonzero = dmin | dmax;
|
|
*must_be_nonzero = dmin & dmax;
|
|
if (xor_mask.high != 0)
|
|
{
|
|
unsigned HOST_WIDE_INT mask
|
|
= ((unsigned HOST_WIDE_INT) 1
|
|
<< floor_log2 (xor_mask.high)) - 1;
|
|
may_be_nonzero->low = ALL_ONES;
|
|
may_be_nonzero->high |= mask;
|
|
must_be_nonzero->low = 0;
|
|
must_be_nonzero->high &= ~mask;
|
|
}
|
|
else if (xor_mask.low != 0)
|
|
{
|
|
unsigned HOST_WIDE_INT mask
|
|
= ((unsigned HOST_WIDE_INT) 1
|
|
<< floor_log2 (xor_mask.low)) - 1;
|
|
may_be_nonzero->low |= mask;
|
|
must_be_nonzero->low &= ~mask;
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
/* Create two value-ranges in *VR0 and *VR1 from the anti-range *AR
|
|
so that *VR0 U *VR1 == *AR. Returns true if that is possible,
|
|
false otherwise. If *AR can be represented with a single range
|
|
*VR1 will be VR_UNDEFINED. */
|
|
|
|
static bool
|
|
ranges_from_anti_range (value_range_t *ar,
|
|
value_range_t *vr0, value_range_t *vr1)
|
|
{
|
|
tree type = TREE_TYPE (ar->min);
|
|
|
|
vr0->type = VR_UNDEFINED;
|
|
vr1->type = VR_UNDEFINED;
|
|
|
|
if (ar->type != VR_ANTI_RANGE
|
|
|| TREE_CODE (ar->min) != INTEGER_CST
|
|
|| TREE_CODE (ar->max) != INTEGER_CST
|
|
|| !vrp_val_min (type)
|
|
|| !vrp_val_max (type))
|
|
return false;
|
|
|
|
if (!vrp_val_is_min (ar->min))
|
|
{
|
|
vr0->type = VR_RANGE;
|
|
vr0->min = vrp_val_min (type);
|
|
vr0->max
|
|
= double_int_to_tree (type,
|
|
tree_to_double_int (ar->min) - double_int_one);
|
|
}
|
|
if (!vrp_val_is_max (ar->max))
|
|
{
|
|
vr1->type = VR_RANGE;
|
|
vr1->min
|
|
= double_int_to_tree (type,
|
|
tree_to_double_int (ar->max) + double_int_one);
|
|
vr1->max = vrp_val_max (type);
|
|
}
|
|
if (vr0->type == VR_UNDEFINED)
|
|
{
|
|
*vr0 = *vr1;
|
|
vr1->type = VR_UNDEFINED;
|
|
}
|
|
|
|
return vr0->type != VR_UNDEFINED;
|
|
}
|
|
|
|
/* Helper to extract a value-range *VR for a multiplicative operation
|
|
*VR0 CODE *VR1. */
|
|
|
|
static void
|
|
extract_range_from_multiplicative_op_1 (value_range_t *vr,
|
|
enum tree_code code,
|
|
value_range_t *vr0, value_range_t *vr1)
|
|
{
|
|
enum value_range_type type;
|
|
tree val[4];
|
|
size_t i;
|
|
tree min, max;
|
|
bool sop;
|
|
int cmp;
|
|
|
|
/* Multiplications, divisions and shifts are a bit tricky to handle,
|
|
depending on the mix of signs we have in the two ranges, we
|
|
need to operate on different values to get the minimum and
|
|
maximum values for the new range. One approach is to figure
|
|
out all the variations of range combinations and do the
|
|
operations.
|
|
|
|
However, this involves several calls to compare_values and it
|
|
is pretty convoluted. It's simpler to do the 4 operations
|
|
(MIN0 OP MIN1, MIN0 OP MAX1, MAX0 OP MIN1 and MAX0 OP MAX0 OP
|
|
MAX1) and then figure the smallest and largest values to form
|
|
the new range. */
|
|
gcc_assert (code == MULT_EXPR
|
|
|| code == TRUNC_DIV_EXPR
|
|
|| code == FLOOR_DIV_EXPR
|
|
|| code == CEIL_DIV_EXPR
|
|
|| code == EXACT_DIV_EXPR
|
|
|| code == ROUND_DIV_EXPR
|
|
|| code == RSHIFT_EXPR
|
|
|| code == LSHIFT_EXPR);
|
|
gcc_assert ((vr0->type == VR_RANGE
|
|
|| (code == MULT_EXPR && vr0->type == VR_ANTI_RANGE))
|
|
&& vr0->type == vr1->type);
|
|
|
|
type = vr0->type;
|
|
|
|
/* Compute the 4 cross operations. */
|
|
sop = false;
|
|
val[0] = vrp_int_const_binop (code, vr0->min, vr1->min);
|
|
if (val[0] == NULL_TREE)
|
|
sop = true;
|
|
|
|
if (vr1->max == vr1->min)
|
|
val[1] = NULL_TREE;
|
|
else
|
|
{
|
|
val[1] = vrp_int_const_binop (code, vr0->min, vr1->max);
|
|
if (val[1] == NULL_TREE)
|
|
sop = true;
|
|
}
|
|
|
|
if (vr0->max == vr0->min)
|
|
val[2] = NULL_TREE;
|
|
else
|
|
{
|
|
val[2] = vrp_int_const_binop (code, vr0->max, vr1->min);
|
|
if (val[2] == NULL_TREE)
|
|
sop = true;
|
|
}
|
|
|
|
if (vr0->min == vr0->max || vr1->min == vr1->max)
|
|
val[3] = NULL_TREE;
|
|
else
|
|
{
|
|
val[3] = vrp_int_const_binop (code, vr0->max, vr1->max);
|
|
if (val[3] == NULL_TREE)
|
|
sop = true;
|
|
}
|
|
|
|
if (sop)
|
|
{
|
|
set_value_range_to_varying (vr);
|
|
return;
|
|
}
|
|
|
|
/* Set MIN to the minimum of VAL[i] and MAX to the maximum
|
|
of VAL[i]. */
|
|
min = val[0];
|
|
max = val[0];
|
|
for (i = 1; i < 4; i++)
|
|
{
|
|
if (!is_gimple_min_invariant (min)
|
|
|| (TREE_OVERFLOW (min) && !is_overflow_infinity (min))
|
|
|| !is_gimple_min_invariant (max)
|
|
|| (TREE_OVERFLOW (max) && !is_overflow_infinity (max)))
|
|
break;
|
|
|
|
if (val[i])
|
|
{
|
|
if (!is_gimple_min_invariant (val[i])
|
|
|| (TREE_OVERFLOW (val[i])
|
|
&& !is_overflow_infinity (val[i])))
|
|
{
|
|
/* If we found an overflowed value, set MIN and MAX
|
|
to it so that we set the resulting range to
|
|
VARYING. */
|
|
min = max = val[i];
|
|
break;
|
|
}
|
|
|
|
if (compare_values (val[i], min) == -1)
|
|
min = val[i];
|
|
|
|
if (compare_values (val[i], max) == 1)
|
|
max = val[i];
|
|
}
|
|
}
|
|
|
|
/* If either MIN or MAX overflowed, then set the resulting range to
|
|
VARYING. But we do accept an overflow infinity
|
|
representation. */
|
|
if (min == NULL_TREE
|
|
|| !is_gimple_min_invariant (min)
|
|
|| (TREE_OVERFLOW (min) && !is_overflow_infinity (min))
|
|
|| max == NULL_TREE
|
|
|| !is_gimple_min_invariant (max)
|
|
|| (TREE_OVERFLOW (max) && !is_overflow_infinity (max)))
|
|
{
|
|
set_value_range_to_varying (vr);
|
|
return;
|
|
}
|
|
|
|
/* We punt if:
|
|
1) [-INF, +INF]
|
|
2) [-INF, +-INF(OVF)]
|
|
3) [+-INF(OVF), +INF]
|
|
4) [+-INF(OVF), +-INF(OVF)]
|
|
We learn nothing when we have INF and INF(OVF) on both sides.
|
|
Note that we do accept [-INF, -INF] and [+INF, +INF] without
|
|
overflow. */
|
|
if ((vrp_val_is_min (min) || is_overflow_infinity (min))
|
|
&& (vrp_val_is_max (max) || is_overflow_infinity (max)))
|
|
{
|
|
set_value_range_to_varying (vr);
|
|
return;
|
|
}
|
|
|
|
cmp = compare_values (min, max);
|
|
if (cmp == -2 || cmp == 1)
|
|
{
|
|
/* If the new range has its limits swapped around (MIN > MAX),
|
|
then the operation caused one of them to wrap around, mark
|
|
the new range VARYING. */
|
|
set_value_range_to_varying (vr);
|
|
}
|
|
else
|
|
set_value_range (vr, type, min, max, NULL);
|
|
}
|
|
|
|
/* Some quadruple precision helpers. */
|
|
static int
|
|
quad_int_cmp (double_int l0, double_int h0,
|
|
double_int l1, double_int h1, bool uns)
|
|
{
|
|
int c = h0.cmp (h1, uns);
|
|
if (c != 0) return c;
|
|
return l0.ucmp (l1);
|
|
}
|
|
|
|
static void
|
|
quad_int_pair_sort (double_int *l0, double_int *h0,
|
|
double_int *l1, double_int *h1, bool uns)
|
|
{
|
|
if (quad_int_cmp (*l0, *h0, *l1, *h1, uns) > 0)
|
|
{
|
|
double_int tmp;
|
|
tmp = *l0; *l0 = *l1; *l1 = tmp;
|
|
tmp = *h0; *h0 = *h1; *h1 = tmp;
|
|
}
|
|
}
|
|
|
|
/* Extract range information from a binary operation CODE based on
|
|
the ranges of each of its operands, *VR0 and *VR1 with resulting
|
|
type EXPR_TYPE. The resulting range is stored in *VR. */
|
|
|
|
static void
|
|
extract_range_from_binary_expr_1 (value_range_t *vr,
|
|
enum tree_code code, tree expr_type,
|
|
value_range_t *vr0_, value_range_t *vr1_)
|
|
{
|
|
value_range_t vr0 = *vr0_, vr1 = *vr1_;
|
|
value_range_t vrtem0 = VR_INITIALIZER, vrtem1 = VR_INITIALIZER;
|
|
enum value_range_type type;
|
|
tree min = NULL_TREE, max = NULL_TREE;
|
|
int cmp;
|
|
|
|
if (!INTEGRAL_TYPE_P (expr_type)
|
|
&& !POINTER_TYPE_P (expr_type))
|
|
{
|
|
set_value_range_to_varying (vr);
|
|
return;
|
|
}
|
|
|
|
/* Not all binary expressions can be applied to ranges in a
|
|
meaningful way. Handle only arithmetic operations. */
|
|
if (code != PLUS_EXPR
|
|
&& code != MINUS_EXPR
|
|
&& code != POINTER_PLUS_EXPR
|
|
&& code != MULT_EXPR
|
|
&& code != TRUNC_DIV_EXPR
|
|
&& code != FLOOR_DIV_EXPR
|
|
&& code != CEIL_DIV_EXPR
|
|
&& code != EXACT_DIV_EXPR
|
|
&& code != ROUND_DIV_EXPR
|
|
&& code != TRUNC_MOD_EXPR
|
|
&& code != RSHIFT_EXPR
|
|
&& code != LSHIFT_EXPR
|
|
&& code != MIN_EXPR
|
|
&& code != MAX_EXPR
|
|
&& code != BIT_AND_EXPR
|
|
&& code != BIT_IOR_EXPR
|
|
&& code != BIT_XOR_EXPR)
|
|
{
|
|
set_value_range_to_varying (vr);
|
|
return;
|
|
}
|
|
|
|
/* If both ranges are UNDEFINED, so is the result. */
|
|
if (vr0.type == VR_UNDEFINED && vr1.type == VR_UNDEFINED)
|
|
{
|
|
set_value_range_to_undefined (vr);
|
|
return;
|
|
}
|
|
/* If one of the ranges is UNDEFINED drop it to VARYING for the following
|
|
code. At some point we may want to special-case operations that
|
|
have UNDEFINED result for all or some value-ranges of the not UNDEFINED
|
|
operand. */
|
|
else if (vr0.type == VR_UNDEFINED)
|
|
set_value_range_to_varying (&vr0);
|
|
else if (vr1.type == VR_UNDEFINED)
|
|
set_value_range_to_varying (&vr1);
|
|
|
|
/* Now canonicalize anti-ranges to ranges when they are not symbolic
|
|
and express ~[] op X as ([]' op X) U ([]'' op X). */
|
|
if (vr0.type == VR_ANTI_RANGE
|
|
&& ranges_from_anti_range (&vr0, &vrtem0, &vrtem1))
|
|
{
|
|
extract_range_from_binary_expr_1 (vr, code, expr_type, &vrtem0, vr1_);
|
|
if (vrtem1.type != VR_UNDEFINED)
|
|
{
|
|
value_range_t vrres = VR_INITIALIZER;
|
|
extract_range_from_binary_expr_1 (&vrres, code, expr_type,
|
|
&vrtem1, vr1_);
|
|
vrp_meet (vr, &vrres);
|
|
}
|
|
return;
|
|
}
|
|
/* Likewise for X op ~[]. */
|
|
if (vr1.type == VR_ANTI_RANGE
|
|
&& ranges_from_anti_range (&vr1, &vrtem0, &vrtem1))
|
|
{
|
|
extract_range_from_binary_expr_1 (vr, code, expr_type, vr0_, &vrtem0);
|
|
if (vrtem1.type != VR_UNDEFINED)
|
|
{
|
|
value_range_t vrres = VR_INITIALIZER;
|
|
extract_range_from_binary_expr_1 (&vrres, code, expr_type,
|
|
vr0_, &vrtem1);
|
|
vrp_meet (vr, &vrres);
|
|
}
|
|
return;
|
|
}
|
|
|
|
/* The type of the resulting value range defaults to VR0.TYPE. */
|
|
type = vr0.type;
|
|
|
|
/* Refuse to operate on VARYING ranges, ranges of different kinds
|
|
and symbolic ranges. As an exception, we allow BIT_AND_EXPR
|
|
because we may be able to derive a useful range even if one of
|
|
the operands is VR_VARYING or symbolic range. Similarly for
|
|
divisions. TODO, we may be able to derive anti-ranges in
|
|
some cases. */
|
|
if (code != BIT_AND_EXPR
|
|
&& code != BIT_IOR_EXPR
|
|
&& code != TRUNC_DIV_EXPR
|
|
&& code != FLOOR_DIV_EXPR
|
|
&& code != CEIL_DIV_EXPR
|
|
&& code != EXACT_DIV_EXPR
|
|
&& code != ROUND_DIV_EXPR
|
|
&& code != TRUNC_MOD_EXPR
|
|
&& code != MIN_EXPR
|
|
&& code != MAX_EXPR
|
|
&& (vr0.type == VR_VARYING
|
|
|| vr1.type == VR_VARYING
|
|
|| vr0.type != vr1.type
|
|
|| symbolic_range_p (&vr0)
|
|
|| symbolic_range_p (&vr1)))
|
|
{
|
|
set_value_range_to_varying (vr);
|
|
return;
|
|
}
|
|
|
|
/* Now evaluate the expression to determine the new range. */
|
|
if (POINTER_TYPE_P (expr_type))
|
|
{
|
|
if (code == MIN_EXPR || code == MAX_EXPR)
|
|
{
|
|
/* For MIN/MAX expressions with pointers, we only care about
|
|
nullness, if both are non null, then the result is nonnull.
|
|
If both are null, then the result is null. Otherwise they
|
|
are varying. */
|
|
if (range_is_nonnull (&vr0) && range_is_nonnull (&vr1))
|
|
set_value_range_to_nonnull (vr, expr_type);
|
|
else if (range_is_null (&vr0) && range_is_null (&vr1))
|
|
set_value_range_to_null (vr, expr_type);
|
|
else
|
|
set_value_range_to_varying (vr);
|
|
}
|
|
else if (code == POINTER_PLUS_EXPR)
|
|
{
|
|
/* For pointer types, we are really only interested in asserting
|
|
whether the expression evaluates to non-NULL. */
|
|
if (range_is_nonnull (&vr0) || range_is_nonnull (&vr1))
|
|
set_value_range_to_nonnull (vr, expr_type);
|
|
else if (range_is_null (&vr0) && range_is_null (&vr1))
|
|
set_value_range_to_null (vr, expr_type);
|
|
else
|
|
set_value_range_to_varying (vr);
|
|
}
|
|
else if (code == BIT_AND_EXPR)
|
|
{
|
|
/* For pointer types, we are really only interested in asserting
|
|
whether the expression evaluates to non-NULL. */
|
|
if (range_is_nonnull (&vr0) && range_is_nonnull (&vr1))
|
|
set_value_range_to_nonnull (vr, expr_type);
|
|
else if (range_is_null (&vr0) || range_is_null (&vr1))
|
|
set_value_range_to_null (vr, expr_type);
|
|
else
|
|
set_value_range_to_varying (vr);
|
|
}
|
|
else
|
|
set_value_range_to_varying (vr);
|
|
|
|
return;
|
|
}
|
|
|
|
/* For integer ranges, apply the operation to each end of the
|
|
range and see what we end up with. */
|
|
if (code == PLUS_EXPR || code == MINUS_EXPR)
|
|
{
|
|
/* If we have a PLUS_EXPR with two VR_RANGE integer constant
|
|
ranges compute the precise range for such case if possible. */
|
|
if (range_int_cst_p (&vr0)
|
|
&& range_int_cst_p (&vr1)
|
|
/* We need as many bits as the possibly unsigned inputs. */
|
|
&& TYPE_PRECISION (expr_type) <= HOST_BITS_PER_DOUBLE_INT)
|
|
{
|
|
double_int min0 = tree_to_double_int (vr0.min);
|
|
double_int max0 = tree_to_double_int (vr0.max);
|
|
double_int min1 = tree_to_double_int (vr1.min);
|
|
double_int max1 = tree_to_double_int (vr1.max);
|
|
bool uns = TYPE_UNSIGNED (expr_type);
|
|
double_int type_min
|
|
= double_int::min_value (TYPE_PRECISION (expr_type), uns);
|
|
double_int type_max
|
|
= double_int::max_value (TYPE_PRECISION (expr_type), uns);
|
|
double_int dmin, dmax;
|
|
int min_ovf = 0;
|
|
int max_ovf = 0;
|
|
|
|
if (code == PLUS_EXPR)
|
|
{
|
|
dmin = min0 + min1;
|
|
dmax = max0 + max1;
|
|
|
|
/* Check for overflow in double_int. */
|
|
if (min1.cmp (double_int_zero, uns) != dmin.cmp (min0, uns))
|
|
min_ovf = min0.cmp (dmin, uns);
|
|
if (max1.cmp (double_int_zero, uns) != dmax.cmp (max0, uns))
|
|
max_ovf = max0.cmp (dmax, uns);
|
|
}
|
|
else /* if (code == MINUS_EXPR) */
|
|
{
|
|
dmin = min0 - max1;
|
|
dmax = max0 - min1;
|
|
|
|
if (double_int_zero.cmp (max1, uns) != dmin.cmp (min0, uns))
|
|
min_ovf = min0.cmp (max1, uns);
|
|
if (double_int_zero.cmp (min1, uns) != dmax.cmp (max0, uns))
|
|
max_ovf = max0.cmp (min1, uns);
|
|
}
|
|
|
|
/* For non-wrapping arithmetic look at possibly smaller
|
|
value-ranges of the type. */
|
|
if (!TYPE_OVERFLOW_WRAPS (expr_type))
|
|
{
|
|
if (vrp_val_min (expr_type))
|
|
type_min = tree_to_double_int (vrp_val_min (expr_type));
|
|
if (vrp_val_max (expr_type))
|
|
type_max = tree_to_double_int (vrp_val_max (expr_type));
|
|
}
|
|
|
|
/* Check for type overflow. */
|
|
if (min_ovf == 0)
|
|
{
|
|
if (dmin.cmp (type_min, uns) == -1)
|
|
min_ovf = -1;
|
|
else if (dmin.cmp (type_max, uns) == 1)
|
|
min_ovf = 1;
|
|
}
|
|
if (max_ovf == 0)
|
|
{
|
|
if (dmax.cmp (type_min, uns) == -1)
|
|
max_ovf = -1;
|
|
else if (dmax.cmp (type_max, uns) == 1)
|
|
max_ovf = 1;
|
|
}
|
|
|
|
if (TYPE_OVERFLOW_WRAPS (expr_type))
|
|
{
|
|
/* If overflow wraps, truncate the values and adjust the
|
|
range kind and bounds appropriately. */
|
|
double_int tmin
|
|
= dmin.ext (TYPE_PRECISION (expr_type), uns);
|
|
double_int tmax
|
|
= dmax.ext (TYPE_PRECISION (expr_type), uns);
|
|
if (min_ovf == max_ovf)
|
|
{
|
|
/* No overflow or both overflow or underflow. The
|
|
range kind stays VR_RANGE. */
|
|
min = double_int_to_tree (expr_type, tmin);
|
|
max = double_int_to_tree (expr_type, tmax);
|
|
}
|
|
else if (min_ovf == -1
|
|
&& max_ovf == 1)
|
|
{
|
|
/* Underflow and overflow, drop to VR_VARYING. */
|
|
set_value_range_to_varying (vr);
|
|
return;
|
|
}
|
|
else
|
|
{
|
|
/* Min underflow or max overflow. The range kind
|
|
changes to VR_ANTI_RANGE. */
|
|
bool covers = false;
|
|
double_int tem = tmin;
|
|
gcc_assert ((min_ovf == -1 && max_ovf == 0)
|
|
|| (max_ovf == 1 && min_ovf == 0));
|
|
type = VR_ANTI_RANGE;
|
|
tmin = tmax + double_int_one;
|
|
if (tmin.cmp (tmax, uns) < 0)
|
|
covers = true;
|
|
tmax = tem + double_int_minus_one;
|
|
if (tmax.cmp (tem, uns) > 0)
|
|
covers = true;
|
|
/* If the anti-range would cover nothing, drop to varying.
|
|
Likewise if the anti-range bounds are outside of the
|
|
types values. */
|
|
if (covers || tmin.cmp (tmax, uns) > 0)
|
|
{
|
|
set_value_range_to_varying (vr);
|
|
return;
|
|
}
|
|
min = double_int_to_tree (expr_type, tmin);
|
|
max = double_int_to_tree (expr_type, tmax);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* If overflow does not wrap, saturate to the types min/max
|
|
value. */
|
|
if (min_ovf == -1)
|
|
{
|
|
if (needs_overflow_infinity (expr_type)
|
|
&& supports_overflow_infinity (expr_type))
|
|
min = negative_overflow_infinity (expr_type);
|
|
else
|
|
min = double_int_to_tree (expr_type, type_min);
|
|
}
|
|
else if (min_ovf == 1)
|
|
{
|
|
if (needs_overflow_infinity (expr_type)
|
|
&& supports_overflow_infinity (expr_type))
|
|
min = positive_overflow_infinity (expr_type);
|
|
else
|
|
min = double_int_to_tree (expr_type, type_max);
|
|
}
|
|
else
|
|
min = double_int_to_tree (expr_type, dmin);
|
|
|
|
if (max_ovf == -1)
|
|
{
|
|
if (needs_overflow_infinity (expr_type)
|
|
&& supports_overflow_infinity (expr_type))
|
|
max = negative_overflow_infinity (expr_type);
|
|
else
|
|
max = double_int_to_tree (expr_type, type_min);
|
|
}
|
|
else if (max_ovf == 1)
|
|
{
|
|
if (needs_overflow_infinity (expr_type)
|
|
&& supports_overflow_infinity (expr_type))
|
|
max = positive_overflow_infinity (expr_type);
|
|
else
|
|
max = double_int_to_tree (expr_type, type_max);
|
|
}
|
|
else
|
|
max = double_int_to_tree (expr_type, dmax);
|
|
}
|
|
if (needs_overflow_infinity (expr_type)
|
|
&& supports_overflow_infinity (expr_type))
|
|
{
|
|
if (is_negative_overflow_infinity (vr0.min)
|
|
|| (code == PLUS_EXPR
|
|
? is_negative_overflow_infinity (vr1.min)
|
|
: is_positive_overflow_infinity (vr1.max)))
|
|
min = negative_overflow_infinity (expr_type);
|
|
if (is_positive_overflow_infinity (vr0.max)
|
|
|| (code == PLUS_EXPR
|
|
? is_positive_overflow_infinity (vr1.max)
|
|
: is_negative_overflow_infinity (vr1.min)))
|
|
max = positive_overflow_infinity (expr_type);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* For other cases, for example if we have a PLUS_EXPR with two
|
|
VR_ANTI_RANGEs, drop to VR_VARYING. It would take more effort
|
|
to compute a precise range for such a case.
|
|
??? General even mixed range kind operations can be expressed
|
|
by for example transforming ~[3, 5] + [1, 2] to range-only
|
|
operations and a union primitive:
|
|
[-INF, 2] + [1, 2] U [5, +INF] + [1, 2]
|
|
[-INF+1, 4] U [6, +INF(OVF)]
|
|
though usually the union is not exactly representable with
|
|
a single range or anti-range as the above is
|
|
[-INF+1, +INF(OVF)] intersected with ~[5, 5]
|
|
but one could use a scheme similar to equivalences for this. */
|
|
set_value_range_to_varying (vr);
|
|
return;
|
|
}
|
|
}
|
|
else if (code == MIN_EXPR
|
|
|| code == MAX_EXPR)
|
|
{
|
|
if (vr0.type == VR_RANGE
|
|
&& !symbolic_range_p (&vr0))
|
|
{
|
|
type = VR_RANGE;
|
|
if (vr1.type == VR_RANGE
|
|
&& !symbolic_range_p (&vr1))
|
|
{
|
|
/* For operations that make the resulting range directly
|
|
proportional to the original ranges, apply the operation to
|
|
the same end of each range. */
|
|
min = vrp_int_const_binop (code, vr0.min, vr1.min);
|
|
max = vrp_int_const_binop (code, vr0.max, vr1.max);
|
|
}
|
|
else if (code == MIN_EXPR)
|
|
{
|
|
min = vrp_val_min (expr_type);
|
|
max = vr0.max;
|
|
}
|
|
else if (code == MAX_EXPR)
|
|
{
|
|
min = vr0.min;
|
|
max = vrp_val_max (expr_type);
|
|
}
|
|
}
|
|
else if (vr1.type == VR_RANGE
|
|
&& !symbolic_range_p (&vr1))
|
|
{
|
|
type = VR_RANGE;
|
|
if (code == MIN_EXPR)
|
|
{
|
|
min = vrp_val_min (expr_type);
|
|
max = vr1.max;
|
|
}
|
|
else if (code == MAX_EXPR)
|
|
{
|
|
min = vr1.min;
|
|
max = vrp_val_max (expr_type);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
set_value_range_to_varying (vr);
|
|
return;
|
|
}
|
|
}
|
|
else if (code == MULT_EXPR)
|
|
{
|
|
/* Fancy code so that with unsigned, [-3,-1]*[-3,-1] does not
|
|
drop to varying. */
|
|
if (range_int_cst_p (&vr0)
|
|
&& range_int_cst_p (&vr1)
|
|
&& TYPE_OVERFLOW_WRAPS (expr_type))
|
|
{
|
|
double_int min0, max0, min1, max1, sizem1, size;
|
|
double_int prod0l, prod0h, prod1l, prod1h,
|
|
prod2l, prod2h, prod3l, prod3h;
|
|
bool uns0, uns1, uns;
|
|
|
|
sizem1 = double_int::max_value (TYPE_PRECISION (expr_type), true);
|
|
size = sizem1 + double_int_one;
|
|
|
|
min0 = tree_to_double_int (vr0.min);
|
|
max0 = tree_to_double_int (vr0.max);
|
|
min1 = tree_to_double_int (vr1.min);
|
|
max1 = tree_to_double_int (vr1.max);
|
|
|
|
uns0 = TYPE_UNSIGNED (expr_type);
|
|
uns1 = uns0;
|
|
|
|
/* Canonicalize the intervals. */
|
|
if (TYPE_UNSIGNED (expr_type))
|
|
{
|
|
double_int min2 = size - min0;
|
|
if (!min2.is_zero () && min2.cmp (max0, true) < 0)
|
|
{
|
|
min0 = -min2;
|
|
max0 -= size;
|
|
uns0 = false;
|
|
}
|
|
|
|
min2 = size - min1;
|
|
if (!min2.is_zero () && min2.cmp (max1, true) < 0)
|
|
{
|
|
min1 = -min2;
|
|
max1 -= size;
|
|
uns1 = false;
|
|
}
|
|
}
|
|
uns = uns0 & uns1;
|
|
|
|
bool overflow;
|
|
prod0l = min0.wide_mul_with_sign (min1, true, &prod0h, &overflow);
|
|
if (!uns0 && min0.is_negative ())
|
|
prod0h -= min1;
|
|
if (!uns1 && min1.is_negative ())
|
|
prod0h -= min0;
|
|
|
|
prod1l = min0.wide_mul_with_sign (max1, true, &prod1h, &overflow);
|
|
if (!uns0 && min0.is_negative ())
|
|
prod1h -= max1;
|
|
if (!uns1 && max1.is_negative ())
|
|
prod1h -= min0;
|
|
|
|
prod2l = max0.wide_mul_with_sign (min1, true, &prod2h, &overflow);
|
|
if (!uns0 && max0.is_negative ())
|
|
prod2h -= min1;
|
|
if (!uns1 && min1.is_negative ())
|
|
prod2h -= max0;
|
|
|
|
prod3l = max0.wide_mul_with_sign (max1, true, &prod3h, &overflow);
|
|
if (!uns0 && max0.is_negative ())
|
|
prod3h -= max1;
|
|
if (!uns1 && max1.is_negative ())
|
|
prod3h -= max0;
|
|
|
|
/* Sort the 4 products. */
|
|
quad_int_pair_sort (&prod0l, &prod0h, &prod3l, &prod3h, uns);
|
|
quad_int_pair_sort (&prod1l, &prod1h, &prod2l, &prod2h, uns);
|
|
quad_int_pair_sort (&prod0l, &prod0h, &prod1l, &prod1h, uns);
|
|
quad_int_pair_sort (&prod2l, &prod2h, &prod3l, &prod3h, uns);
|
|
|
|
/* Max - min. */
|
|
if (prod0l.is_zero ())
|
|
{
|
|
prod1l = double_int_zero;
|
|
prod1h = -prod0h;
|
|
}
|
|
else
|
|
{
|
|
prod1l = -prod0l;
|
|
prod1h = ~prod0h;
|
|
}
|
|
prod2l = prod3l + prod1l;
|
|
prod2h = prod3h + prod1h;
|
|
if (prod2l.ult (prod3l))
|
|
prod2h += double_int_one; /* carry */
|
|
|
|
if (!prod2h.is_zero ()
|
|
|| prod2l.cmp (sizem1, true) >= 0)
|
|
{
|
|
/* the range covers all values. */
|
|
set_value_range_to_varying (vr);
|
|
return;
|
|
}
|
|
|
|
/* The following should handle the wrapping and selecting
|
|
VR_ANTI_RANGE for us. */
|
|
min = double_int_to_tree (expr_type, prod0l);
|
|
max = double_int_to_tree (expr_type, prod3l);
|
|
set_and_canonicalize_value_range (vr, VR_RANGE, min, max, NULL);
|
|
return;
|
|
}
|
|
|
|
/* If we have an unsigned MULT_EXPR with two VR_ANTI_RANGEs,
|
|
drop to VR_VARYING. It would take more effort to compute a
|
|
precise range for such a case. For example, if we have
|
|
op0 == 65536 and op1 == 65536 with their ranges both being
|
|
~[0,0] on a 32-bit machine, we would have op0 * op1 == 0, so
|
|
we cannot claim that the product is in ~[0,0]. Note that we
|
|
are guaranteed to have vr0.type == vr1.type at this
|
|
point. */
|
|
if (vr0.type == VR_ANTI_RANGE
|
|
&& !TYPE_OVERFLOW_UNDEFINED (expr_type))
|
|
{
|
|
set_value_range_to_varying (vr);
|
|
return;
|
|
}
|
|
|
|
extract_range_from_multiplicative_op_1 (vr, code, &vr0, &vr1);
|
|
return;
|
|
}
|
|
else if (code == RSHIFT_EXPR
|
|
|| code == LSHIFT_EXPR)
|
|
{
|
|
/* If we have a RSHIFT_EXPR with any shift values outside [0..prec-1],
|
|
then drop to VR_VARYING. Outside of this range we get undefined
|
|
behavior from the shift operation. We cannot even trust
|
|
SHIFT_COUNT_TRUNCATED at this stage, because that applies to rtl
|
|
shifts, and the operation at the tree level may be widened. */
|
|
if (range_int_cst_p (&vr1)
|
|
&& compare_tree_int (vr1.min, 0) >= 0
|
|
&& compare_tree_int (vr1.max, TYPE_PRECISION (expr_type)) == -1)
|
|
{
|
|
if (code == RSHIFT_EXPR)
|
|
{
|
|
extract_range_from_multiplicative_op_1 (vr, code, &vr0, &vr1);
|
|
return;
|
|
}
|
|
/* We can map lshifts by constants to MULT_EXPR handling. */
|
|
else if (code == LSHIFT_EXPR
|
|
&& range_int_cst_singleton_p (&vr1))
|
|
{
|
|
bool saved_flag_wrapv;
|
|
value_range_t vr1p = VR_INITIALIZER;
|
|
vr1p.type = VR_RANGE;
|
|
vr1p.min
|
|
= double_int_to_tree (expr_type,
|
|
double_int_one
|
|
.llshift (TREE_INT_CST_LOW (vr1.min),
|
|
TYPE_PRECISION (expr_type)));
|
|
vr1p.max = vr1p.min;
|
|
/* We have to use a wrapping multiply though as signed overflow
|
|
on lshifts is implementation defined in C89. */
|
|
saved_flag_wrapv = flag_wrapv;
|
|
flag_wrapv = 1;
|
|
extract_range_from_binary_expr_1 (vr, MULT_EXPR, expr_type,
|
|
&vr0, &vr1p);
|
|
flag_wrapv = saved_flag_wrapv;
|
|
return;
|
|
}
|
|
else if (code == LSHIFT_EXPR
|
|
&& range_int_cst_p (&vr0))
|
|
{
|
|
int prec = TYPE_PRECISION (expr_type);
|
|
int overflow_pos = prec;
|
|
int bound_shift;
|
|
double_int bound, complement, low_bound, high_bound;
|
|
bool uns = TYPE_UNSIGNED (expr_type);
|
|
bool in_bounds = false;
|
|
|
|
if (!uns)
|
|
overflow_pos -= 1;
|
|
|
|
bound_shift = overflow_pos - TREE_INT_CST_LOW (vr1.max);
|
|
/* If bound_shift == HOST_BITS_PER_DOUBLE_INT, the llshift can
|
|
overflow. However, for that to happen, vr1.max needs to be
|
|
zero, which means vr1 is a singleton range of zero, which
|
|
means it should be handled by the previous LSHIFT_EXPR
|
|
if-clause. */
|
|
bound = double_int_one.llshift (bound_shift, prec);
|
|
complement = ~(bound - double_int_one);
|
|
|
|
if (uns)
|
|
{
|
|
low_bound = bound;
|
|
high_bound = complement.zext (prec);
|
|
if (tree_to_double_int (vr0.max).ult (low_bound))
|
|
{
|
|
/* [5, 6] << [1, 2] == [10, 24]. */
|
|
/* We're shifting out only zeroes, the value increases
|
|
monotonically. */
|
|
in_bounds = true;
|
|
}
|
|
else if (high_bound.ult (tree_to_double_int (vr0.min)))
|
|
{
|
|
/* [0xffffff00, 0xffffffff] << [1, 2]
|
|
== [0xfffffc00, 0xfffffffe]. */
|
|
/* We're shifting out only ones, the value decreases
|
|
monotonically. */
|
|
in_bounds = true;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* [-1, 1] << [1, 2] == [-4, 4]. */
|
|
low_bound = complement.sext (prec);
|
|
high_bound = bound;
|
|
if (tree_to_double_int (vr0.max).slt (high_bound)
|
|
&& low_bound.slt (tree_to_double_int (vr0.min)))
|
|
{
|
|
/* For non-negative numbers, we're shifting out only
|
|
zeroes, the value increases monotonically.
|
|
For negative numbers, we're shifting out only ones, the
|
|
value decreases monotomically. */
|
|
in_bounds = true;
|
|
}
|
|
}
|
|
|
|
if (in_bounds)
|
|
{
|
|
extract_range_from_multiplicative_op_1 (vr, code, &vr0, &vr1);
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
set_value_range_to_varying (vr);
|
|
return;
|
|
}
|
|
else if (code == TRUNC_DIV_EXPR
|
|
|| code == FLOOR_DIV_EXPR
|
|
|| code == CEIL_DIV_EXPR
|
|
|| code == EXACT_DIV_EXPR
|
|
|| code == ROUND_DIV_EXPR)
|
|
{
|
|
if (vr0.type != VR_RANGE || symbolic_range_p (&vr0))
|
|
{
|
|
/* For division, if op1 has VR_RANGE but op0 does not, something
|
|
can be deduced just from that range. Say [min, max] / [4, max]
|
|
gives [min / 4, max / 4] range. */
|
|
if (vr1.type == VR_RANGE
|
|
&& !symbolic_range_p (&vr1)
|
|
&& range_includes_zero_p (vr1.min, vr1.max) == 0)
|
|
{
|
|
vr0.type = type = VR_RANGE;
|
|
vr0.min = vrp_val_min (expr_type);
|
|
vr0.max = vrp_val_max (expr_type);
|
|
}
|
|
else
|
|
{
|
|
set_value_range_to_varying (vr);
|
|
return;
|
|
}
|
|
}
|
|
|
|
/* For divisions, if flag_non_call_exceptions is true, we must
|
|
not eliminate a division by zero. */
|
|
if (cfun->can_throw_non_call_exceptions
|
|
&& (vr1.type != VR_RANGE
|
|
|| range_includes_zero_p (vr1.min, vr1.max) != 0))
|
|
{
|
|
set_value_range_to_varying (vr);
|
|
return;
|
|
}
|
|
|
|
/* For divisions, if op0 is VR_RANGE, we can deduce a range
|
|
even if op1 is VR_VARYING, VR_ANTI_RANGE, symbolic or can
|
|
include 0. */
|
|
if (vr0.type == VR_RANGE
|
|
&& (vr1.type != VR_RANGE
|
|
|| range_includes_zero_p (vr1.min, vr1.max) != 0))
|
|
{
|
|
tree zero = build_int_cst (TREE_TYPE (vr0.min), 0);
|
|
int cmp;
|
|
|
|
min = NULL_TREE;
|
|
max = NULL_TREE;
|
|
if (TYPE_UNSIGNED (expr_type)
|
|
|| value_range_nonnegative_p (&vr1))
|
|
{
|
|
/* For unsigned division or when divisor is known
|
|
to be non-negative, the range has to cover
|
|
all numbers from 0 to max for positive max
|
|
and all numbers from min to 0 for negative min. */
|
|
cmp = compare_values (vr0.max, zero);
|
|
if (cmp == -1)
|
|
max = zero;
|
|
else if (cmp == 0 || cmp == 1)
|
|
max = vr0.max;
|
|
else
|
|
type = VR_VARYING;
|
|
cmp = compare_values (vr0.min, zero);
|
|
if (cmp == 1)
|
|
min = zero;
|
|
else if (cmp == 0 || cmp == -1)
|
|
min = vr0.min;
|
|
else
|
|
type = VR_VARYING;
|
|
}
|
|
else
|
|
{
|
|
/* Otherwise the range is -max .. max or min .. -min
|
|
depending on which bound is bigger in absolute value,
|
|
as the division can change the sign. */
|
|
abs_extent_range (vr, vr0.min, vr0.max);
|
|
return;
|
|
}
|
|
if (type == VR_VARYING)
|
|
{
|
|
set_value_range_to_varying (vr);
|
|
return;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
extract_range_from_multiplicative_op_1 (vr, code, &vr0, &vr1);
|
|
return;
|
|
}
|
|
}
|
|
else if (code == TRUNC_MOD_EXPR)
|
|
{
|
|
if (vr1.type != VR_RANGE
|
|
|| range_includes_zero_p (vr1.min, vr1.max) != 0
|
|
|| vrp_val_is_min (vr1.min))
|
|
{
|
|
set_value_range_to_varying (vr);
|
|
return;
|
|
}
|
|
type = VR_RANGE;
|
|
/* Compute MAX <|vr1.min|, |vr1.max|> - 1. */
|
|
max = fold_unary_to_constant (ABS_EXPR, expr_type, vr1.min);
|
|
if (tree_int_cst_lt (max, vr1.max))
|
|
max = vr1.max;
|
|
max = int_const_binop (MINUS_EXPR, max, integer_one_node);
|
|
/* If the dividend is non-negative the modulus will be
|
|
non-negative as well. */
|
|
if (TYPE_UNSIGNED (expr_type)
|
|
|| value_range_nonnegative_p (&vr0))
|
|
min = build_int_cst (TREE_TYPE (max), 0);
|
|
else
|
|
min = fold_unary_to_constant (NEGATE_EXPR, expr_type, max);
|
|
}
|
|
else if (code == BIT_AND_EXPR || code == BIT_IOR_EXPR || code == BIT_XOR_EXPR)
|
|
{
|
|
bool int_cst_range0, int_cst_range1;
|
|
double_int may_be_nonzero0, may_be_nonzero1;
|
|
double_int must_be_nonzero0, must_be_nonzero1;
|
|
|
|
int_cst_range0 = zero_nonzero_bits_from_vr (&vr0, &may_be_nonzero0,
|
|
&must_be_nonzero0);
|
|
int_cst_range1 = zero_nonzero_bits_from_vr (&vr1, &may_be_nonzero1,
|
|
&must_be_nonzero1);
|
|
|
|
type = VR_RANGE;
|
|
if (code == BIT_AND_EXPR)
|
|
{
|
|
double_int dmax;
|
|
min = double_int_to_tree (expr_type,
|
|
must_be_nonzero0 & must_be_nonzero1);
|
|
dmax = may_be_nonzero0 & may_be_nonzero1;
|
|
/* If both input ranges contain only negative values we can
|
|
truncate the result range maximum to the minimum of the
|
|
input range maxima. */
|
|
if (int_cst_range0 && int_cst_range1
|
|
&& tree_int_cst_sgn (vr0.max) < 0
|
|
&& tree_int_cst_sgn (vr1.max) < 0)
|
|
{
|
|
dmax = dmax.min (tree_to_double_int (vr0.max),
|
|
TYPE_UNSIGNED (expr_type));
|
|
dmax = dmax.min (tree_to_double_int (vr1.max),
|
|
TYPE_UNSIGNED (expr_type));
|
|
}
|
|
/* If either input range contains only non-negative values
|
|
we can truncate the result range maximum to the respective
|
|
maximum of the input range. */
|
|
if (int_cst_range0 && tree_int_cst_sgn (vr0.min) >= 0)
|
|
dmax = dmax.min (tree_to_double_int (vr0.max),
|
|
TYPE_UNSIGNED (expr_type));
|
|
if (int_cst_range1 && tree_int_cst_sgn (vr1.min) >= 0)
|
|
dmax = dmax.min (tree_to_double_int (vr1.max),
|
|
TYPE_UNSIGNED (expr_type));
|
|
max = double_int_to_tree (expr_type, dmax);
|
|
}
|
|
else if (code == BIT_IOR_EXPR)
|
|
{
|
|
double_int dmin;
|
|
max = double_int_to_tree (expr_type,
|
|
may_be_nonzero0 | may_be_nonzero1);
|
|
dmin = must_be_nonzero0 | must_be_nonzero1;
|
|
/* If the input ranges contain only positive values we can
|
|
truncate the minimum of the result range to the maximum
|
|
of the input range minima. */
|
|
if (int_cst_range0 && int_cst_range1
|
|
&& tree_int_cst_sgn (vr0.min) >= 0
|
|
&& tree_int_cst_sgn (vr1.min) >= 0)
|
|
{
|
|
dmin = dmin.max (tree_to_double_int (vr0.min),
|
|
TYPE_UNSIGNED (expr_type));
|
|
dmin = dmin.max (tree_to_double_int (vr1.min),
|
|
TYPE_UNSIGNED (expr_type));
|
|
}
|
|
/* If either input range contains only negative values
|
|
we can truncate the minimum of the result range to the
|
|
respective minimum range. */
|
|
if (int_cst_range0 && tree_int_cst_sgn (vr0.max) < 0)
|
|
dmin = dmin.max (tree_to_double_int (vr0.min),
|
|
TYPE_UNSIGNED (expr_type));
|
|
if (int_cst_range1 && tree_int_cst_sgn (vr1.max) < 0)
|
|
dmin = dmin.max (tree_to_double_int (vr1.min),
|
|
TYPE_UNSIGNED (expr_type));
|
|
min = double_int_to_tree (expr_type, dmin);
|
|
}
|
|
else if (code == BIT_XOR_EXPR)
|
|
{
|
|
double_int result_zero_bits, result_one_bits;
|
|
result_zero_bits = (must_be_nonzero0 & must_be_nonzero1)
|
|
| ~(may_be_nonzero0 | may_be_nonzero1);
|
|
result_one_bits = must_be_nonzero0.and_not (may_be_nonzero1)
|
|
| must_be_nonzero1.and_not (may_be_nonzero0);
|
|
max = double_int_to_tree (expr_type, ~result_zero_bits);
|
|
min = double_int_to_tree (expr_type, result_one_bits);
|
|
/* If the range has all positive or all negative values the
|
|
result is better than VARYING. */
|
|
if (tree_int_cst_sgn (min) < 0
|
|
|| tree_int_cst_sgn (max) >= 0)
|
|
;
|
|
else
|
|
max = min = NULL_TREE;
|
|
}
|
|
}
|
|
else
|
|
gcc_unreachable ();
|
|
|
|
/* If either MIN or MAX overflowed, then set the resulting range to
|
|
VARYING. But we do accept an overflow infinity
|
|
representation. */
|
|
if (min == NULL_TREE
|
|
|| !is_gimple_min_invariant (min)
|
|
|| (TREE_OVERFLOW (min) && !is_overflow_infinity (min))
|
|
|| max == NULL_TREE
|
|
|| !is_gimple_min_invariant (max)
|
|
|| (TREE_OVERFLOW (max) && !is_overflow_infinity (max)))
|
|
{
|
|
set_value_range_to_varying (vr);
|
|
return;
|
|
}
|
|
|
|
/* We punt if:
|
|
1) [-INF, +INF]
|
|
2) [-INF, +-INF(OVF)]
|
|
3) [+-INF(OVF), +INF]
|
|
4) [+-INF(OVF), +-INF(OVF)]
|
|
We learn nothing when we have INF and INF(OVF) on both sides.
|
|
Note that we do accept [-INF, -INF] and [+INF, +INF] without
|
|
overflow. */
|
|
if ((vrp_val_is_min (min) || is_overflow_infinity (min))
|
|
&& (vrp_val_is_max (max) || is_overflow_infinity (max)))
|
|
{
|
|
set_value_range_to_varying (vr);
|
|
return;
|
|
}
|
|
|
|
cmp = compare_values (min, max);
|
|
if (cmp == -2 || cmp == 1)
|
|
{
|
|
/* If the new range has its limits swapped around (MIN > MAX),
|
|
then the operation caused one of them to wrap around, mark
|
|
the new range VARYING. */
|
|
set_value_range_to_varying (vr);
|
|
}
|
|
else
|
|
set_value_range (vr, type, min, max, NULL);
|
|
}
|
|
|
|
/* Extract range information from a binary expression OP0 CODE OP1 based on
|
|
the ranges of each of its operands with resulting type EXPR_TYPE.
|
|
The resulting range is stored in *VR. */
|
|
|
|
static void
|
|
extract_range_from_binary_expr (value_range_t *vr,
|
|
enum tree_code code,
|
|
tree expr_type, tree op0, tree op1)
|
|
{
|
|
value_range_t vr0 = VR_INITIALIZER;
|
|
value_range_t vr1 = VR_INITIALIZER;
|
|
|
|
/* Get value ranges for each operand. For constant operands, create
|
|
a new value range with the operand to simplify processing. */
|
|
if (TREE_CODE (op0) == SSA_NAME)
|
|
vr0 = *(get_value_range (op0));
|
|
else if (is_gimple_min_invariant (op0))
|
|
set_value_range_to_value (&vr0, op0, NULL);
|
|
else
|
|
set_value_range_to_varying (&vr0);
|
|
|
|
if (TREE_CODE (op1) == SSA_NAME)
|
|
vr1 = *(get_value_range (op1));
|
|
else if (is_gimple_min_invariant (op1))
|
|
set_value_range_to_value (&vr1, op1, NULL);
|
|
else
|
|
set_value_range_to_varying (&vr1);
|
|
|
|
extract_range_from_binary_expr_1 (vr, code, expr_type, &vr0, &vr1);
|
|
}
|
|
|
|
/* Extract range information from a unary operation CODE based on
|
|
the range of its operand *VR0 with type OP0_TYPE with resulting type TYPE.
|
|
The The resulting range is stored in *VR. */
|
|
|
|
static void
|
|
extract_range_from_unary_expr_1 (value_range_t *vr,
|
|
enum tree_code code, tree type,
|
|
value_range_t *vr0_, tree op0_type)
|
|
{
|
|
value_range_t vr0 = *vr0_, vrtem0 = VR_INITIALIZER, vrtem1 = VR_INITIALIZER;
|
|
|
|
/* VRP only operates on integral and pointer types. */
|
|
if (!(INTEGRAL_TYPE_P (op0_type)
|
|
|| POINTER_TYPE_P (op0_type))
|
|
|| !(INTEGRAL_TYPE_P (type)
|
|
|| POINTER_TYPE_P (type)))
|
|
{
|
|
set_value_range_to_varying (vr);
|
|
return;
|
|
}
|
|
|
|
/* If VR0 is UNDEFINED, so is the result. */
|
|
if (vr0.type == VR_UNDEFINED)
|
|
{
|
|
set_value_range_to_undefined (vr);
|
|
return;
|
|
}
|
|
|
|
/* Handle operations that we express in terms of others. */
|
|
if (code == PAREN_EXPR)
|
|
{
|
|
/* PAREN_EXPR is a simple copy. */
|
|
copy_value_range (vr, &vr0);
|
|
return;
|
|
}
|
|
else if (code == NEGATE_EXPR)
|
|
{
|
|
/* -X is simply 0 - X, so re-use existing code that also handles
|
|
anti-ranges fine. */
|
|
value_range_t zero = VR_INITIALIZER;
|
|
set_value_range_to_value (&zero, build_int_cst (type, 0), NULL);
|
|
extract_range_from_binary_expr_1 (vr, MINUS_EXPR, type, &zero, &vr0);
|
|
return;
|
|
}
|
|
else if (code == BIT_NOT_EXPR)
|
|
{
|
|
/* ~X is simply -1 - X, so re-use existing code that also handles
|
|
anti-ranges fine. */
|
|
value_range_t minusone = VR_INITIALIZER;
|
|
set_value_range_to_value (&minusone, build_int_cst (type, -1), NULL);
|
|
extract_range_from_binary_expr_1 (vr, MINUS_EXPR,
|
|
type, &minusone, &vr0);
|
|
return;
|
|
}
|
|
|
|
/* Now canonicalize anti-ranges to ranges when they are not symbolic
|
|
and express op ~[] as (op []') U (op []''). */
|
|
if (vr0.type == VR_ANTI_RANGE
|
|
&& ranges_from_anti_range (&vr0, &vrtem0, &vrtem1))
|
|
{
|
|
extract_range_from_unary_expr_1 (vr, code, type, &vrtem0, op0_type);
|
|
if (vrtem1.type != VR_UNDEFINED)
|
|
{
|
|
value_range_t vrres = VR_INITIALIZER;
|
|
extract_range_from_unary_expr_1 (&vrres, code, type,
|
|
&vrtem1, op0_type);
|
|
vrp_meet (vr, &vrres);
|
|
}
|
|
return;
|
|
}
|
|
|
|
if (CONVERT_EXPR_CODE_P (code))
|
|
{
|
|
tree inner_type = op0_type;
|
|
tree outer_type = type;
|
|
|
|
/* If the expression evaluates to a pointer, we are only interested in
|
|
determining if it evaluates to NULL [0, 0] or non-NULL (~[0, 0]). */
|
|
if (POINTER_TYPE_P (type))
|
|
{
|
|
if (range_is_nonnull (&vr0))
|
|
set_value_range_to_nonnull (vr, type);
|
|
else if (range_is_null (&vr0))
|
|
set_value_range_to_null (vr, type);
|
|
else
|
|
set_value_range_to_varying (vr);
|
|
return;
|
|
}
|
|
|
|
/* If VR0 is varying and we increase the type precision, assume
|
|
a full range for the following transformation. */
|
|
if (vr0.type == VR_VARYING
|
|
&& INTEGRAL_TYPE_P (inner_type)
|
|
&& TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type))
|
|
{
|
|
vr0.type = VR_RANGE;
|
|
vr0.min = TYPE_MIN_VALUE (inner_type);
|
|
vr0.max = TYPE_MAX_VALUE (inner_type);
|
|
}
|
|
|
|
/* If VR0 is a constant range or anti-range and the conversion is
|
|
not truncating we can convert the min and max values and
|
|
canonicalize the resulting range. Otherwise we can do the
|
|
conversion if the size of the range is less than what the
|
|
precision of the target type can represent and the range is
|
|
not an anti-range. */
|
|
if ((vr0.type == VR_RANGE
|
|
|| vr0.type == VR_ANTI_RANGE)
|
|
&& TREE_CODE (vr0.min) == INTEGER_CST
|
|
&& TREE_CODE (vr0.max) == INTEGER_CST
|
|
&& (!is_overflow_infinity (vr0.min)
|
|
|| (vr0.type == VR_RANGE
|
|
&& TYPE_PRECISION (outer_type) > TYPE_PRECISION (inner_type)
|
|
&& needs_overflow_infinity (outer_type)
|
|
&& supports_overflow_infinity (outer_type)))
|
|
&& (!is_overflow_infinity (vr0.max)
|
|
|| (vr0.type == VR_RANGE
|
|
&& TYPE_PRECISION (outer_type) > TYPE_PRECISION (inner_type)
|
|
&& needs_overflow_infinity (outer_type)
|
|
&& supports_overflow_infinity (outer_type)))
|
|
&& (TYPE_PRECISION (outer_type) >= TYPE_PRECISION (inner_type)
|
|
|| (vr0.type == VR_RANGE
|
|
&& integer_zerop (int_const_binop (RSHIFT_EXPR,
|
|
int_const_binop (MINUS_EXPR, vr0.max, vr0.min),
|
|
size_int (TYPE_PRECISION (outer_type)))))))
|
|
{
|
|
tree new_min, new_max;
|
|
if (is_overflow_infinity (vr0.min))
|
|
new_min = negative_overflow_infinity (outer_type);
|
|
else
|
|
new_min = force_fit_type_double (outer_type,
|
|
tree_to_double_int (vr0.min),
|
|
0, false);
|
|
if (is_overflow_infinity (vr0.max))
|
|
new_max = positive_overflow_infinity (outer_type);
|
|
else
|
|
new_max = force_fit_type_double (outer_type,
|
|
tree_to_double_int (vr0.max),
|
|
0, false);
|
|
set_and_canonicalize_value_range (vr, vr0.type,
|
|
new_min, new_max, NULL);
|
|
return;
|
|
}
|
|
|
|
set_value_range_to_varying (vr);
|
|
return;
|
|
}
|
|
else if (code == ABS_EXPR)
|
|
{
|
|
tree min, max;
|
|
int cmp;
|
|
|
|
/* Pass through vr0 in the easy cases. */
|
|
if (TYPE_UNSIGNED (type)
|
|
|| value_range_nonnegative_p (&vr0))
|
|
{
|
|
copy_value_range (vr, &vr0);
|
|
return;
|
|
}
|
|
|
|
/* For the remaining varying or symbolic ranges we can't do anything
|
|
useful. */
|
|
if (vr0.type == VR_VARYING
|
|
|| symbolic_range_p (&vr0))
|
|
{
|
|
set_value_range_to_varying (vr);
|
|
return;
|
|
}
|
|
|
|
/* -TYPE_MIN_VALUE = TYPE_MIN_VALUE with flag_wrapv so we can't get a
|
|
useful range. */
|
|
if (!TYPE_OVERFLOW_UNDEFINED (type)
|
|
&& ((vr0.type == VR_RANGE
|
|
&& vrp_val_is_min (vr0.min))
|
|
|| (vr0.type == VR_ANTI_RANGE
|
|
&& !vrp_val_is_min (vr0.min))))
|
|
{
|
|
set_value_range_to_varying (vr);
|
|
return;
|
|
}
|
|
|
|
/* ABS_EXPR may flip the range around, if the original range
|
|
included negative values. */
|
|
if (is_overflow_infinity (vr0.min))
|
|
min = positive_overflow_infinity (type);
|
|
else if (!vrp_val_is_min (vr0.min))
|
|
min = fold_unary_to_constant (code, type, vr0.min);
|
|
else if (!needs_overflow_infinity (type))
|
|
min = TYPE_MAX_VALUE (type);
|
|
else if (supports_overflow_infinity (type))
|
|
min = positive_overflow_infinity (type);
|
|
else
|
|
{
|
|
set_value_range_to_varying (vr);
|
|
return;
|
|
}
|
|
|
|
if (is_overflow_infinity (vr0.max))
|
|
max = positive_overflow_infinity (type);
|
|
else if (!vrp_val_is_min (vr0.max))
|
|
max = fold_unary_to_constant (code, type, vr0.max);
|
|
else if (!needs_overflow_infinity (type))
|
|
max = TYPE_MAX_VALUE (type);
|
|
else if (supports_overflow_infinity (type)
|
|
/* We shouldn't generate [+INF, +INF] as set_value_range
|
|
doesn't like this and ICEs. */
|
|
&& !is_positive_overflow_infinity (min))
|
|
max = positive_overflow_infinity (type);
|
|
else
|
|
{
|
|
set_value_range_to_varying (vr);
|
|
return;
|
|
}
|
|
|
|
cmp = compare_values (min, max);
|
|
|
|
/* If a VR_ANTI_RANGEs contains zero, then we have
|
|
~[-INF, min(MIN, MAX)]. */
|
|
if (vr0.type == VR_ANTI_RANGE)
|
|
{
|
|
if (range_includes_zero_p (vr0.min, vr0.max) == 1)
|
|
{
|
|
/* Take the lower of the two values. */
|
|
if (cmp != 1)
|
|
max = min;
|
|
|
|
/* Create ~[-INF, min (abs(MIN), abs(MAX))]
|
|
or ~[-INF + 1, min (abs(MIN), abs(MAX))] when
|
|
flag_wrapv is set and the original anti-range doesn't include
|
|
TYPE_MIN_VALUE, remember -TYPE_MIN_VALUE = TYPE_MIN_VALUE. */
|
|
if (TYPE_OVERFLOW_WRAPS (type))
|
|
{
|
|
tree type_min_value = TYPE_MIN_VALUE (type);
|
|
|
|
min = (vr0.min != type_min_value
|
|
? int_const_binop (PLUS_EXPR, type_min_value,
|
|
integer_one_node)
|
|
: type_min_value);
|
|
}
|
|
else
|
|
{
|
|
if (overflow_infinity_range_p (&vr0))
|
|
min = negative_overflow_infinity (type);
|
|
else
|
|
min = TYPE_MIN_VALUE (type);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* All else has failed, so create the range [0, INF], even for
|
|
flag_wrapv since TYPE_MIN_VALUE is in the original
|
|
anti-range. */
|
|
vr0.type = VR_RANGE;
|
|
min = build_int_cst (type, 0);
|
|
if (needs_overflow_infinity (type))
|
|
{
|
|
if (supports_overflow_infinity (type))
|
|
max = positive_overflow_infinity (type);
|
|
else
|
|
{
|
|
set_value_range_to_varying (vr);
|
|
return;
|
|
}
|
|
}
|
|
else
|
|
max = TYPE_MAX_VALUE (type);
|
|
}
|
|
}
|
|
|
|
/* If the range contains zero then we know that the minimum value in the
|
|
range will be zero. */
|
|
else if (range_includes_zero_p (vr0.min, vr0.max) == 1)
|
|
{
|
|
if (cmp == 1)
|
|
max = min;
|
|
min = build_int_cst (type, 0);
|
|
}
|
|
else
|
|
{
|
|
/* If the range was reversed, swap MIN and MAX. */
|
|
if (cmp == 1)
|
|
{
|
|
tree t = min;
|
|
min = max;
|
|
max = t;
|
|
}
|
|
}
|
|
|
|
cmp = compare_values (min, max);
|
|
if (cmp == -2 || cmp == 1)
|
|
{
|
|
/* If the new range has its limits swapped around (MIN > MAX),
|
|
then the operation caused one of them to wrap around, mark
|
|
the new range VARYING. */
|
|
set_value_range_to_varying (vr);
|
|
}
|
|
else
|
|
set_value_range (vr, vr0.type, min, max, NULL);
|
|
return;
|
|
}
|
|
|
|
/* For unhandled operations fall back to varying. */
|
|
set_value_range_to_varying (vr);
|
|
return;
|
|
}
|
|
|
|
|
|
/* Extract range information from a unary expression CODE OP0 based on
|
|
the range of its operand with resulting type TYPE.
|
|
The resulting range is stored in *VR. */
|
|
|
|
static void
|
|
extract_range_from_unary_expr (value_range_t *vr, enum tree_code code,
|
|
tree type, tree op0)
|
|
{
|
|
value_range_t vr0 = VR_INITIALIZER;
|
|
|
|
/* Get value ranges for the operand. For constant operands, create
|
|
a new value range with the operand to simplify processing. */
|
|
if (TREE_CODE (op0) == SSA_NAME)
|
|
vr0 = *(get_value_range (op0));
|
|
else if (is_gimple_min_invariant (op0))
|
|
set_value_range_to_value (&vr0, op0, NULL);
|
|
else
|
|
set_value_range_to_varying (&vr0);
|
|
|
|
extract_range_from_unary_expr_1 (vr, code, type, &vr0, TREE_TYPE (op0));
|
|
}
|
|
|
|
|
|
/* Extract range information from a conditional expression STMT based on
|
|
the ranges of each of its operands and the expression code. */
|
|
|
|
static void
|
|
extract_range_from_cond_expr (value_range_t *vr, gimple stmt)
|
|
{
|
|
tree op0, op1;
|
|
value_range_t vr0 = VR_INITIALIZER;
|
|
value_range_t vr1 = VR_INITIALIZER;
|
|
|
|
/* Get value ranges for each operand. For constant operands, create
|
|
a new value range with the operand to simplify processing. */
|
|
op0 = gimple_assign_rhs2 (stmt);
|
|
if (TREE_CODE (op0) == SSA_NAME)
|
|
vr0 = *(get_value_range (op0));
|
|
else if (is_gimple_min_invariant (op0))
|
|
set_value_range_to_value (&vr0, op0, NULL);
|
|
else
|
|
set_value_range_to_varying (&vr0);
|
|
|
|
op1 = gimple_assign_rhs3 (stmt);
|
|
if (TREE_CODE (op1) == SSA_NAME)
|
|
vr1 = *(get_value_range (op1));
|
|
else if (is_gimple_min_invariant (op1))
|
|
set_value_range_to_value (&vr1, op1, NULL);
|
|
else
|
|
set_value_range_to_varying (&vr1);
|
|
|
|
/* The resulting value range is the union of the operand ranges */
|
|
copy_value_range (vr, &vr0);
|
|
vrp_meet (vr, &vr1);
|
|
}
|
|
|
|
|
|
/* Extract range information from a comparison expression EXPR based
|
|
on the range of its operand and the expression code. */
|
|
|
|
static void
|
|
extract_range_from_comparison (value_range_t *vr, enum tree_code code,
|
|
tree type, tree op0, tree op1)
|
|
{
|
|
bool sop = false;
|
|
tree val;
|
|
|
|
val = vrp_evaluate_conditional_warnv_with_ops (code, op0, op1, false, &sop,
|
|
NULL);
|
|
|
|
/* A disadvantage of using a special infinity as an overflow
|
|
representation is that we lose the ability to record overflow
|
|
when we don't have an infinity. So we have to ignore a result
|
|
which relies on overflow. */
|
|
|
|
if (val && !is_overflow_infinity (val) && !sop)
|
|
{
|
|
/* Since this expression was found on the RHS of an assignment,
|
|
its type may be different from _Bool. Convert VAL to EXPR's
|
|
type. */
|
|
val = fold_convert (type, val);
|
|
if (is_gimple_min_invariant (val))
|
|
set_value_range_to_value (vr, val, vr->equiv);
|
|
else
|
|
set_value_range (vr, VR_RANGE, val, val, vr->equiv);
|
|
}
|
|
else
|
|
/* The result of a comparison is always true or false. */
|
|
set_value_range_to_truthvalue (vr, type);
|
|
}
|
|
|
|
/* Try to derive a nonnegative or nonzero range out of STMT relying
|
|
primarily on generic routines in fold in conjunction with range data.
|
|
Store the result in *VR */
|
|
|
|
static void
|
|
extract_range_basic (value_range_t *vr, gimple stmt)
|
|
{
|
|
bool sop = false;
|
|
tree type = gimple_expr_type (stmt);
|
|
|
|
if (INTEGRAL_TYPE_P (type)
|
|
&& gimple_stmt_nonnegative_warnv_p (stmt, &sop))
|
|
set_value_range_to_nonnegative (vr, type,
|
|
sop || stmt_overflow_infinity (stmt));
|
|
else if (vrp_stmt_computes_nonzero (stmt, &sop)
|
|
&& !sop)
|
|
set_value_range_to_nonnull (vr, type);
|
|
else
|
|
set_value_range_to_varying (vr);
|
|
}
|
|
|
|
|
|
/* Try to compute a useful range out of assignment STMT and store it
|
|
in *VR. */
|
|
|
|
static void
|
|
extract_range_from_assignment (value_range_t *vr, gimple stmt)
|
|
{
|
|
enum tree_code code = gimple_assign_rhs_code (stmt);
|
|
|
|
if (code == ASSERT_EXPR)
|
|
extract_range_from_assert (vr, gimple_assign_rhs1 (stmt));
|
|
else if (code == SSA_NAME)
|
|
extract_range_from_ssa_name (vr, gimple_assign_rhs1 (stmt));
|
|
else if (TREE_CODE_CLASS (code) == tcc_binary)
|
|
extract_range_from_binary_expr (vr, gimple_assign_rhs_code (stmt),
|
|
gimple_expr_type (stmt),
|
|
gimple_assign_rhs1 (stmt),
|
|
gimple_assign_rhs2 (stmt));
|
|
else if (TREE_CODE_CLASS (code) == tcc_unary)
|
|
extract_range_from_unary_expr (vr, gimple_assign_rhs_code (stmt),
|
|
gimple_expr_type (stmt),
|
|
gimple_assign_rhs1 (stmt));
|
|
else if (code == COND_EXPR)
|
|
extract_range_from_cond_expr (vr, stmt);
|
|
else if (TREE_CODE_CLASS (code) == tcc_comparison)
|
|
extract_range_from_comparison (vr, gimple_assign_rhs_code (stmt),
|
|
gimple_expr_type (stmt),
|
|
gimple_assign_rhs1 (stmt),
|
|
gimple_assign_rhs2 (stmt));
|
|
else if (get_gimple_rhs_class (code) == GIMPLE_SINGLE_RHS
|
|
&& is_gimple_min_invariant (gimple_assign_rhs1 (stmt)))
|
|
set_value_range_to_value (vr, gimple_assign_rhs1 (stmt), NULL);
|
|
else
|
|
set_value_range_to_varying (vr);
|
|
|
|
if (vr->type == VR_VARYING)
|
|
extract_range_basic (vr, stmt);
|
|
}
|
|
|
|
/* Given a range VR, a LOOP and a variable VAR, determine whether it
|
|
would be profitable to adjust VR using scalar evolution information
|
|
for VAR. If so, update VR with the new limits. */
|
|
|
|
static void
|
|
adjust_range_with_scev (value_range_t *vr, struct loop *loop,
|
|
gimple stmt, tree var)
|
|
{
|
|
tree init, step, chrec, tmin, tmax, min, max, type, tem;
|
|
enum ev_direction dir;
|
|
|
|
/* TODO. Don't adjust anti-ranges. An anti-range may provide
|
|
better opportunities than a regular range, but I'm not sure. */
|
|
if (vr->type == VR_ANTI_RANGE)
|
|
return;
|
|
|
|
chrec = instantiate_parameters (loop, analyze_scalar_evolution (loop, var));
|
|
|
|
/* Like in PR19590, scev can return a constant function. */
|
|
if (is_gimple_min_invariant (chrec))
|
|
{
|
|
set_value_range_to_value (vr, chrec, vr->equiv);
|
|
return;
|
|
}
|
|
|
|
if (TREE_CODE (chrec) != POLYNOMIAL_CHREC)
|
|
return;
|
|
|
|
init = initial_condition_in_loop_num (chrec, loop->num);
|
|
tem = op_with_constant_singleton_value_range (init);
|
|
if (tem)
|
|
init = tem;
|
|
step = evolution_part_in_loop_num (chrec, loop->num);
|
|
tem = op_with_constant_singleton_value_range (step);
|
|
if (tem)
|
|
step = tem;
|
|
|
|
/* If STEP is symbolic, we can't know whether INIT will be the
|
|
minimum or maximum value in the range. Also, unless INIT is
|
|
a simple expression, compare_values and possibly other functions
|
|
in tree-vrp won't be able to handle it. */
|
|
if (step == NULL_TREE
|
|
|| !is_gimple_min_invariant (step)
|
|
|| !valid_value_p (init))
|
|
return;
|
|
|
|
dir = scev_direction (chrec);
|
|
if (/* Do not adjust ranges if we do not know whether the iv increases
|
|
or decreases, ... */
|
|
dir == EV_DIR_UNKNOWN
|
|
/* ... or if it may wrap. */
|
|
|| scev_probably_wraps_p (init, step, stmt, get_chrec_loop (chrec),
|
|
true))
|
|
return;
|
|
|
|
/* We use TYPE_MIN_VALUE and TYPE_MAX_VALUE here instead of
|
|
negative_overflow_infinity and positive_overflow_infinity,
|
|
because we have concluded that the loop probably does not
|
|
wrap. */
|
|
|
|
type = TREE_TYPE (var);
|
|
if (POINTER_TYPE_P (type) || !TYPE_MIN_VALUE (type))
|
|
tmin = lower_bound_in_type (type, type);
|
|
else
|
|
tmin = TYPE_MIN_VALUE (type);
|
|
if (POINTER_TYPE_P (type) || !TYPE_MAX_VALUE (type))
|
|
tmax = upper_bound_in_type (type, type);
|
|
else
|
|
tmax = TYPE_MAX_VALUE (type);
|
|
|
|
/* Try to use estimated number of iterations for the loop to constrain the
|
|
final value in the evolution. */
|
|
if (TREE_CODE (step) == INTEGER_CST
|
|
&& is_gimple_val (init)
|
|
&& (TREE_CODE (init) != SSA_NAME
|
|
|| get_value_range (init)->type == VR_RANGE))
|
|
{
|
|
double_int nit;
|
|
|
|
/* We are only entering here for loop header PHI nodes, so using
|
|
the number of latch executions is the correct thing to use. */
|
|
if (max_loop_iterations (loop, &nit))
|
|
{
|
|
value_range_t maxvr = VR_INITIALIZER;
|
|
double_int dtmp;
|
|
bool unsigned_p = TYPE_UNSIGNED (TREE_TYPE (step));
|
|
bool overflow = false;
|
|
|
|
dtmp = tree_to_double_int (step)
|
|
.mul_with_sign (nit, unsigned_p, &overflow);
|
|
/* If the multiplication overflowed we can't do a meaningful
|
|
adjustment. Likewise if the result doesn't fit in the type
|
|
of the induction variable. For a signed type we have to
|
|
check whether the result has the expected signedness which
|
|
is that of the step as number of iterations is unsigned. */
|
|
if (!overflow
|
|
&& double_int_fits_to_tree_p (TREE_TYPE (init), dtmp)
|
|
&& (unsigned_p
|
|
|| ((dtmp.high ^ TREE_INT_CST_HIGH (step)) >= 0)))
|
|
{
|
|
tem = double_int_to_tree (TREE_TYPE (init), dtmp);
|
|
extract_range_from_binary_expr (&maxvr, PLUS_EXPR,
|
|
TREE_TYPE (init), init, tem);
|
|
/* Likewise if the addition did. */
|
|
if (maxvr.type == VR_RANGE)
|
|
{
|
|
tmin = maxvr.min;
|
|
tmax = maxvr.max;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
if (vr->type == VR_VARYING || vr->type == VR_UNDEFINED)
|
|
{
|
|
min = tmin;
|
|
max = tmax;
|
|
|
|
/* For VARYING or UNDEFINED ranges, just about anything we get
|
|
from scalar evolutions should be better. */
|
|
|
|
if (dir == EV_DIR_DECREASES)
|
|
max = init;
|
|
else
|
|
min = init;
|
|
|
|
/* If we would create an invalid range, then just assume we
|
|
know absolutely nothing. This may be over-conservative,
|
|
but it's clearly safe, and should happen only in unreachable
|
|
parts of code, or for invalid programs. */
|
|
if (compare_values (min, max) == 1)
|
|
return;
|
|
|
|
set_value_range (vr, VR_RANGE, min, max, vr->equiv);
|
|
}
|
|
else if (vr->type == VR_RANGE)
|
|
{
|
|
min = vr->min;
|
|
max = vr->max;
|
|
|
|
if (dir == EV_DIR_DECREASES)
|
|
{
|
|
/* INIT is the maximum value. If INIT is lower than VR->MAX
|
|
but no smaller than VR->MIN, set VR->MAX to INIT. */
|
|
if (compare_values (init, max) == -1)
|
|
max = init;
|
|
|
|
/* According to the loop information, the variable does not
|
|
overflow. If we think it does, probably because of an
|
|
overflow due to arithmetic on a different INF value,
|
|
reset now. */
|
|
if (is_negative_overflow_infinity (min)
|
|
|| compare_values (min, tmin) == -1)
|
|
min = tmin;
|
|
|
|
}
|
|
else
|
|
{
|
|
/* If INIT is bigger than VR->MIN, set VR->MIN to INIT. */
|
|
if (compare_values (init, min) == 1)
|
|
min = init;
|
|
|
|
if (is_positive_overflow_infinity (max)
|
|
|| compare_values (tmax, max) == -1)
|
|
max = tmax;
|
|
}
|
|
|
|
/* If we just created an invalid range with the minimum
|
|
greater than the maximum, we fail conservatively.
|
|
This should happen only in unreachable
|
|
parts of code, or for invalid programs. */
|
|
if (compare_values (min, max) == 1)
|
|
return;
|
|
|
|
set_value_range (vr, VR_RANGE, min, max, vr->equiv);
|
|
}
|
|
}
|
|
|
|
/* Return true if VAR may overflow at STMT. This checks any available
|
|
loop information to see if we can determine that VAR does not
|
|
overflow. */
|
|
|
|
static bool
|
|
vrp_var_may_overflow (tree var, gimple stmt)
|
|
{
|
|
struct loop *l;
|
|
tree chrec, init, step;
|
|
|
|
if (current_loops == NULL)
|
|
return true;
|
|
|
|
l = loop_containing_stmt (stmt);
|
|
if (l == NULL
|
|
|| !loop_outer (l))
|
|
return true;
|
|
|
|
chrec = instantiate_parameters (l, analyze_scalar_evolution (l, var));
|
|
if (TREE_CODE (chrec) != POLYNOMIAL_CHREC)
|
|
return true;
|
|
|
|
init = initial_condition_in_loop_num (chrec, l->num);
|
|
step = evolution_part_in_loop_num (chrec, l->num);
|
|
|
|
if (step == NULL_TREE
|
|
|| !is_gimple_min_invariant (step)
|
|
|| !valid_value_p (init))
|
|
return true;
|
|
|
|
/* If we get here, we know something useful about VAR based on the
|
|
loop information. If it wraps, it may overflow. */
|
|
|
|
if (scev_probably_wraps_p (init, step, stmt, get_chrec_loop (chrec),
|
|
true))
|
|
return true;
|
|
|
|
if (dump_file && (dump_flags & TDF_DETAILS) != 0)
|
|
{
|
|
print_generic_expr (dump_file, var, 0);
|
|
fprintf (dump_file, ": loop information indicates does not overflow\n");
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
|
|
/* Given two numeric value ranges VR0, VR1 and a comparison code COMP:
|
|
|
|
- Return BOOLEAN_TRUE_NODE if VR0 COMP VR1 always returns true for
|
|
all the values in the ranges.
|
|
|
|
- Return BOOLEAN_FALSE_NODE if the comparison always returns false.
|
|
|
|
- Return NULL_TREE if it is not always possible to determine the
|
|
value of the comparison.
|
|
|
|
Also set *STRICT_OVERFLOW_P to indicate whether a range with an
|
|
overflow infinity was used in the test. */
|
|
|
|
|
|
static tree
|
|
compare_ranges (enum tree_code comp, value_range_t *vr0, value_range_t *vr1,
|
|
bool *strict_overflow_p)
|
|
{
|
|
/* VARYING or UNDEFINED ranges cannot be compared. */
|
|
if (vr0->type == VR_VARYING
|
|
|| vr0->type == VR_UNDEFINED
|
|
|| vr1->type == VR_VARYING
|
|
|| vr1->type == VR_UNDEFINED)
|
|
return NULL_TREE;
|
|
|
|
/* Anti-ranges need to be handled separately. */
|
|
if (vr0->type == VR_ANTI_RANGE || vr1->type == VR_ANTI_RANGE)
|
|
{
|
|
/* If both are anti-ranges, then we cannot compute any
|
|
comparison. */
|
|
if (vr0->type == VR_ANTI_RANGE && vr1->type == VR_ANTI_RANGE)
|
|
return NULL_TREE;
|
|
|
|
/* These comparisons are never statically computable. */
|
|
if (comp == GT_EXPR
|
|
|| comp == GE_EXPR
|
|
|| comp == LT_EXPR
|
|
|| comp == LE_EXPR)
|
|
return NULL_TREE;
|
|
|
|
/* Equality can be computed only between a range and an
|
|
anti-range. ~[VAL1, VAL2] == [VAL1, VAL2] is always false. */
|
|
if (vr0->type == VR_RANGE)
|
|
{
|
|
/* To simplify processing, make VR0 the anti-range. */
|
|
value_range_t *tmp = vr0;
|
|
vr0 = vr1;
|
|
vr1 = tmp;
|
|
}
|
|
|
|
gcc_assert (comp == NE_EXPR || comp == EQ_EXPR);
|
|
|
|
if (compare_values_warnv (vr0->min, vr1->min, strict_overflow_p) == 0
|
|
&& compare_values_warnv (vr0->max, vr1->max, strict_overflow_p) == 0)
|
|
return (comp == NE_EXPR) ? boolean_true_node : boolean_false_node;
|
|
|
|
return NULL_TREE;
|
|
}
|
|
|
|
if (!usable_range_p (vr0, strict_overflow_p)
|
|
|| !usable_range_p (vr1, strict_overflow_p))
|
|
return NULL_TREE;
|
|
|
|
/* Simplify processing. If COMP is GT_EXPR or GE_EXPR, switch the
|
|
operands around and change the comparison code. */
|
|
if (comp == GT_EXPR || comp == GE_EXPR)
|
|
{
|
|
value_range_t *tmp;
|
|
comp = (comp == GT_EXPR) ? LT_EXPR : LE_EXPR;
|
|
tmp = vr0;
|
|
vr0 = vr1;
|
|
vr1 = tmp;
|
|
}
|
|
|
|
if (comp == EQ_EXPR)
|
|
{
|
|
/* Equality may only be computed if both ranges represent
|
|
exactly one value. */
|
|
if (compare_values_warnv (vr0->min, vr0->max, strict_overflow_p) == 0
|
|
&& compare_values_warnv (vr1->min, vr1->max, strict_overflow_p) == 0)
|
|
{
|
|
int cmp_min = compare_values_warnv (vr0->min, vr1->min,
|
|
strict_overflow_p);
|
|
int cmp_max = compare_values_warnv (vr0->max, vr1->max,
|
|
strict_overflow_p);
|
|
if (cmp_min == 0 && cmp_max == 0)
|
|
return boolean_true_node;
|
|
else if (cmp_min != -2 && cmp_max != -2)
|
|
return boolean_false_node;
|
|
}
|
|
/* If [V0_MIN, V1_MAX] < [V1_MIN, V1_MAX] then V0 != V1. */
|
|
else if (compare_values_warnv (vr0->min, vr1->max,
|
|
strict_overflow_p) == 1
|
|
|| compare_values_warnv (vr1->min, vr0->max,
|
|
strict_overflow_p) == 1)
|
|
return boolean_false_node;
|
|
|
|
return NULL_TREE;
|
|
}
|
|
else if (comp == NE_EXPR)
|
|
{
|
|
int cmp1, cmp2;
|
|
|
|
/* If VR0 is completely to the left or completely to the right
|
|
of VR1, they are always different. Notice that we need to
|
|
make sure that both comparisons yield similar results to
|
|
avoid comparing values that cannot be compared at
|
|
compile-time. */
|
|
cmp1 = compare_values_warnv (vr0->max, vr1->min, strict_overflow_p);
|
|
cmp2 = compare_values_warnv (vr0->min, vr1->max, strict_overflow_p);
|
|
if ((cmp1 == -1 && cmp2 == -1) || (cmp1 == 1 && cmp2 == 1))
|
|
return boolean_true_node;
|
|
|
|
/* If VR0 and VR1 represent a single value and are identical,
|
|
return false. */
|
|
else if (compare_values_warnv (vr0->min, vr0->max,
|
|
strict_overflow_p) == 0
|
|
&& compare_values_warnv (vr1->min, vr1->max,
|
|
strict_overflow_p) == 0
|
|
&& compare_values_warnv (vr0->min, vr1->min,
|
|
strict_overflow_p) == 0
|
|
&& compare_values_warnv (vr0->max, vr1->max,
|
|
strict_overflow_p) == 0)
|
|
return boolean_false_node;
|
|
|
|
/* Otherwise, they may or may not be different. */
|
|
else
|
|
return NULL_TREE;
|
|
}
|
|
else if (comp == LT_EXPR || comp == LE_EXPR)
|
|
{
|
|
int tst;
|
|
|
|
/* If VR0 is to the left of VR1, return true. */
|
|
tst = compare_values_warnv (vr0->max, vr1->min, strict_overflow_p);
|
|
if ((comp == LT_EXPR && tst == -1)
|
|
|| (comp == LE_EXPR && (tst == -1 || tst == 0)))
|
|
{
|
|
if (overflow_infinity_range_p (vr0)
|
|
|| overflow_infinity_range_p (vr1))
|
|
*strict_overflow_p = true;
|
|
return boolean_true_node;
|
|
}
|
|
|
|
/* If VR0 is to the right of VR1, return false. */
|
|
tst = compare_values_warnv (vr0->min, vr1->max, strict_overflow_p);
|
|
if ((comp == LT_EXPR && (tst == 0 || tst == 1))
|
|
|| (comp == LE_EXPR && tst == 1))
|
|
{
|
|
if (overflow_infinity_range_p (vr0)
|
|
|| overflow_infinity_range_p (vr1))
|
|
*strict_overflow_p = true;
|
|
return boolean_false_node;
|
|
}
|
|
|
|
/* Otherwise, we don't know. */
|
|
return NULL_TREE;
|
|
}
|
|
|
|
gcc_unreachable ();
|
|
}
|
|
|
|
|
|
/* Given a value range VR, a value VAL and a comparison code COMP, return
|
|
BOOLEAN_TRUE_NODE if VR COMP VAL always returns true for all the
|
|
values in VR. Return BOOLEAN_FALSE_NODE if the comparison
|
|
always returns false. Return NULL_TREE if it is not always
|
|
possible to determine the value of the comparison. Also set
|
|
*STRICT_OVERFLOW_P to indicate whether a range with an overflow
|
|
infinity was used in the test. */
|
|
|
|
static tree
|
|
compare_range_with_value (enum tree_code comp, value_range_t *vr, tree val,
|
|
bool *strict_overflow_p)
|
|
{
|
|
if (vr->type == VR_VARYING || vr->type == VR_UNDEFINED)
|
|
return NULL_TREE;
|
|
|
|
/* Anti-ranges need to be handled separately. */
|
|
if (vr->type == VR_ANTI_RANGE)
|
|
{
|
|
/* For anti-ranges, the only predicates that we can compute at
|
|
compile time are equality and inequality. */
|
|
if (comp == GT_EXPR
|
|
|| comp == GE_EXPR
|
|
|| comp == LT_EXPR
|
|
|| comp == LE_EXPR)
|
|
return NULL_TREE;
|
|
|
|
/* ~[VAL_1, VAL_2] OP VAL is known if VAL_1 <= VAL <= VAL_2. */
|
|
if (value_inside_range (val, vr->min, vr->max) == 1)
|
|
return (comp == NE_EXPR) ? boolean_true_node : boolean_false_node;
|
|
|
|
return NULL_TREE;
|
|
}
|
|
|
|
if (!usable_range_p (vr, strict_overflow_p))
|
|
return NULL_TREE;
|
|
|
|
if (comp == EQ_EXPR)
|
|
{
|
|
/* EQ_EXPR may only be computed if VR represents exactly
|
|
one value. */
|
|
if (compare_values_warnv (vr->min, vr->max, strict_overflow_p) == 0)
|
|
{
|
|
int cmp = compare_values_warnv (vr->min, val, strict_overflow_p);
|
|
if (cmp == 0)
|
|
return boolean_true_node;
|
|
else if (cmp == -1 || cmp == 1 || cmp == 2)
|
|
return boolean_false_node;
|
|
}
|
|
else if (compare_values_warnv (val, vr->min, strict_overflow_p) == -1
|
|
|| compare_values_warnv (vr->max, val, strict_overflow_p) == -1)
|
|
return boolean_false_node;
|
|
|
|
return NULL_TREE;
|
|
}
|
|
else if (comp == NE_EXPR)
|
|
{
|
|
/* If VAL is not inside VR, then they are always different. */
|
|
if (compare_values_warnv (vr->max, val, strict_overflow_p) == -1
|
|
|| compare_values_warnv (vr->min, val, strict_overflow_p) == 1)
|
|
return boolean_true_node;
|
|
|
|
/* If VR represents exactly one value equal to VAL, then return
|
|
false. */
|
|
if (compare_values_warnv (vr->min, vr->max, strict_overflow_p) == 0
|
|
&& compare_values_warnv (vr->min, val, strict_overflow_p) == 0)
|
|
return boolean_false_node;
|
|
|
|
/* Otherwise, they may or may not be different. */
|
|
return NULL_TREE;
|
|
}
|
|
else if (comp == LT_EXPR || comp == LE_EXPR)
|
|
{
|
|
int tst;
|
|
|
|
/* If VR is to the left of VAL, return true. */
|
|
tst = compare_values_warnv (vr->max, val, strict_overflow_p);
|
|
if ((comp == LT_EXPR && tst == -1)
|
|
|| (comp == LE_EXPR && (tst == -1 || tst == 0)))
|
|
{
|
|
if (overflow_infinity_range_p (vr))
|
|
*strict_overflow_p = true;
|
|
return boolean_true_node;
|
|
}
|
|
|
|
/* If VR is to the right of VAL, return false. */
|
|
tst = compare_values_warnv (vr->min, val, strict_overflow_p);
|
|
if ((comp == LT_EXPR && (tst == 0 || tst == 1))
|
|
|| (comp == LE_EXPR && tst == 1))
|
|
{
|
|
if (overflow_infinity_range_p (vr))
|
|
*strict_overflow_p = true;
|
|
return boolean_false_node;
|
|
}
|
|
|
|
/* Otherwise, we don't know. */
|
|
return NULL_TREE;
|
|
}
|
|
else if (comp == GT_EXPR || comp == GE_EXPR)
|
|
{
|
|
int tst;
|
|
|
|
/* If VR is to the right of VAL, return true. */
|
|
tst = compare_values_warnv (vr->min, val, strict_overflow_p);
|
|
if ((comp == GT_EXPR && tst == 1)
|
|
|| (comp == GE_EXPR && (tst == 0 || tst == 1)))
|
|
{
|
|
if (overflow_infinity_range_p (vr))
|
|
*strict_overflow_p = true;
|
|
return boolean_true_node;
|
|
}
|
|
|
|
/* If VR is to the left of VAL, return false. */
|
|
tst = compare_values_warnv (vr->max, val, strict_overflow_p);
|
|
if ((comp == GT_EXPR && (tst == -1 || tst == 0))
|
|
|| (comp == GE_EXPR && tst == -1))
|
|
{
|
|
if (overflow_infinity_range_p (vr))
|
|
*strict_overflow_p = true;
|
|
return boolean_false_node;
|
|
}
|
|
|
|
/* Otherwise, we don't know. */
|
|
return NULL_TREE;
|
|
}
|
|
|
|
gcc_unreachable ();
|
|
}
|
|
|
|
|
|
/* Debugging dumps. */
|
|
|
|
void dump_value_range (FILE *, value_range_t *);
|
|
void debug_value_range (value_range_t *);
|
|
void dump_all_value_ranges (FILE *);
|
|
void debug_all_value_ranges (void);
|
|
void dump_vr_equiv (FILE *, bitmap);
|
|
void debug_vr_equiv (bitmap);
|
|
|
|
|
|
/* Dump value range VR to FILE. */
|
|
|
|
void
|
|
dump_value_range (FILE *file, value_range_t *vr)
|
|
{
|
|
if (vr == NULL)
|
|
fprintf (file, "[]");
|
|
else if (vr->type == VR_UNDEFINED)
|
|
fprintf (file, "UNDEFINED");
|
|
else if (vr->type == VR_RANGE || vr->type == VR_ANTI_RANGE)
|
|
{
|
|
tree type = TREE_TYPE (vr->min);
|
|
|
|
fprintf (file, "%s[", (vr->type == VR_ANTI_RANGE) ? "~" : "");
|
|
|
|
if (is_negative_overflow_infinity (vr->min))
|
|
fprintf (file, "-INF(OVF)");
|
|
else if (INTEGRAL_TYPE_P (type)
|
|
&& !TYPE_UNSIGNED (type)
|
|
&& vrp_val_is_min (vr->min))
|
|
fprintf (file, "-INF");
|
|
else
|
|
print_generic_expr (file, vr->min, 0);
|
|
|
|
fprintf (file, ", ");
|
|
|
|
if (is_positive_overflow_infinity (vr->max))
|
|
fprintf (file, "+INF(OVF)");
|
|
else if (INTEGRAL_TYPE_P (type)
|
|
&& vrp_val_is_max (vr->max))
|
|
fprintf (file, "+INF");
|
|
else
|
|
print_generic_expr (file, vr->max, 0);
|
|
|
|
fprintf (file, "]");
|
|
|
|
if (vr->equiv)
|
|
{
|
|
bitmap_iterator bi;
|
|
unsigned i, c = 0;
|
|
|
|
fprintf (file, " EQUIVALENCES: { ");
|
|
|
|
EXECUTE_IF_SET_IN_BITMAP (vr->equiv, 0, i, bi)
|
|
{
|
|
print_generic_expr (file, ssa_name (i), 0);
|
|
fprintf (file, " ");
|
|
c++;
|
|
}
|
|
|
|
fprintf (file, "} (%u elements)", c);
|
|
}
|
|
}
|
|
else if (vr->type == VR_VARYING)
|
|
fprintf (file, "VARYING");
|
|
else
|
|
fprintf (file, "INVALID RANGE");
|
|
}
|
|
|
|
|
|
/* Dump value range VR to stderr. */
|
|
|
|
DEBUG_FUNCTION void
|
|
debug_value_range (value_range_t *vr)
|
|
{
|
|
dump_value_range (stderr, vr);
|
|
fprintf (stderr, "\n");
|
|
}
|
|
|
|
|
|
/* Dump value ranges of all SSA_NAMEs to FILE. */
|
|
|
|
void
|
|
dump_all_value_ranges (FILE *file)
|
|
{
|
|
size_t i;
|
|
|
|
for (i = 0; i < num_vr_values; i++)
|
|
{
|
|
if (vr_value[i])
|
|
{
|
|
print_generic_expr (file, ssa_name (i), 0);
|
|
fprintf (file, ": ");
|
|
dump_value_range (file, vr_value[i]);
|
|
fprintf (file, "\n");
|
|
}
|
|
}
|
|
|
|
fprintf (file, "\n");
|
|
}
|
|
|
|
|
|
/* Dump all value ranges to stderr. */
|
|
|
|
DEBUG_FUNCTION void
|
|
debug_all_value_ranges (void)
|
|
{
|
|
dump_all_value_ranges (stderr);
|
|
}
|
|
|
|
|
|
/* Given a COND_EXPR COND of the form 'V OP W', and an SSA name V,
|
|
create a new SSA name N and return the assertion assignment
|
|
'V = ASSERT_EXPR <V, V OP W>'. */
|
|
|
|
static gimple
|
|
build_assert_expr_for (tree cond, tree v)
|
|
{
|
|
tree a;
|
|
gimple assertion;
|
|
|
|
gcc_assert (TREE_CODE (v) == SSA_NAME
|
|
&& COMPARISON_CLASS_P (cond));
|
|
|
|
a = build2 (ASSERT_EXPR, TREE_TYPE (v), v, cond);
|
|
assertion = gimple_build_assign (NULL_TREE, a);
|
|
|
|
/* The new ASSERT_EXPR, creates a new SSA name that replaces the
|
|
operand of the ASSERT_EXPR. Create it so the new name and the old one
|
|
are registered in the replacement table so that we can fix the SSA web
|
|
after adding all the ASSERT_EXPRs. */
|
|
create_new_def_for (v, assertion, NULL);
|
|
|
|
return assertion;
|
|
}
|
|
|
|
|
|
/* Return false if EXPR is a predicate expression involving floating
|
|
point values. */
|
|
|
|
static inline bool
|
|
fp_predicate (gimple stmt)
|
|
{
|
|
GIMPLE_CHECK (stmt, GIMPLE_COND);
|
|
|
|
return FLOAT_TYPE_P (TREE_TYPE (gimple_cond_lhs (stmt)));
|
|
}
|
|
|
|
|
|
/* If the range of values taken by OP can be inferred after STMT executes,
|
|
return the comparison code (COMP_CODE_P) and value (VAL_P) that
|
|
describes the inferred range. Return true if a range could be
|
|
inferred. */
|
|
|
|
static bool
|
|
infer_value_range (gimple stmt, tree op, enum tree_code *comp_code_p, tree *val_p)
|
|
{
|
|
*val_p = NULL_TREE;
|
|
*comp_code_p = ERROR_MARK;
|
|
|
|
/* Do not attempt to infer anything in names that flow through
|
|
abnormal edges. */
|
|
if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (op))
|
|
return false;
|
|
|
|
/* Similarly, don't infer anything from statements that may throw
|
|
exceptions. */
|
|
if (stmt_could_throw_p (stmt))
|
|
return false;
|
|
|
|
/* If STMT is the last statement of a basic block with no
|
|
successors, there is no point inferring anything about any of its
|
|
operands. We would not be able to find a proper insertion point
|
|
for the assertion, anyway. */
|
|
if (stmt_ends_bb_p (stmt) && EDGE_COUNT (gimple_bb (stmt)->succs) == 0)
|
|
return false;
|
|
|
|
/* We can only assume that a pointer dereference will yield
|
|
non-NULL if -fdelete-null-pointer-checks is enabled. */
|
|
if (flag_delete_null_pointer_checks
|
|
&& POINTER_TYPE_P (TREE_TYPE (op))
|
|
&& gimple_code (stmt) != GIMPLE_ASM)
|
|
{
|
|
unsigned num_uses, num_loads, num_stores;
|
|
|
|
count_uses_and_derefs (op, stmt, &num_uses, &num_loads, &num_stores);
|
|
if (num_loads + num_stores > 0)
|
|
{
|
|
*val_p = build_int_cst (TREE_TYPE (op), 0);
|
|
*comp_code_p = NE_EXPR;
|
|
return true;
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
|
|
void dump_asserts_for (FILE *, tree);
|
|
void debug_asserts_for (tree);
|
|
void dump_all_asserts (FILE *);
|
|
void debug_all_asserts (void);
|
|
|
|
/* Dump all the registered assertions for NAME to FILE. */
|
|
|
|
void
|
|
dump_asserts_for (FILE *file, tree name)
|
|
{
|
|
assert_locus_t loc;
|
|
|
|
fprintf (file, "Assertions to be inserted for ");
|
|
print_generic_expr (file, name, 0);
|
|
fprintf (file, "\n");
|
|
|
|
loc = asserts_for[SSA_NAME_VERSION (name)];
|
|
while (loc)
|
|
{
|
|
fprintf (file, "\t");
|
|
print_gimple_stmt (file, gsi_stmt (loc->si), 0, 0);
|
|
fprintf (file, "\n\tBB #%d", loc->bb->index);
|
|
if (loc->e)
|
|
{
|
|
fprintf (file, "\n\tEDGE %d->%d", loc->e->src->index,
|
|
loc->e->dest->index);
|
|
dump_edge_info (file, loc->e, dump_flags, 0);
|
|
}
|
|
fprintf (file, "\n\tPREDICATE: ");
|
|
print_generic_expr (file, name, 0);
|
|
fprintf (file, " %s ", tree_code_name[(int)loc->comp_code]);
|
|
print_generic_expr (file, loc->val, 0);
|
|
fprintf (file, "\n\n");
|
|
loc = loc->next;
|
|
}
|
|
|
|
fprintf (file, "\n");
|
|
}
|
|
|
|
|
|
/* Dump all the registered assertions for NAME to stderr. */
|
|
|
|
DEBUG_FUNCTION void
|
|
debug_asserts_for (tree name)
|
|
{
|
|
dump_asserts_for (stderr, name);
|
|
}
|
|
|
|
|
|
/* Dump all the registered assertions for all the names to FILE. */
|
|
|
|
void
|
|
dump_all_asserts (FILE *file)
|
|
{
|
|
unsigned i;
|
|
bitmap_iterator bi;
|
|
|
|
fprintf (file, "\nASSERT_EXPRs to be inserted\n\n");
|
|
EXECUTE_IF_SET_IN_BITMAP (need_assert_for, 0, i, bi)
|
|
dump_asserts_for (file, ssa_name (i));
|
|
fprintf (file, "\n");
|
|
}
|
|
|
|
|
|
/* Dump all the registered assertions for all the names to stderr. */
|
|
|
|
DEBUG_FUNCTION void
|
|
debug_all_asserts (void)
|
|
{
|
|
dump_all_asserts (stderr);
|
|
}
|
|
|
|
|
|
/* If NAME doesn't have an ASSERT_EXPR registered for asserting
|
|
'EXPR COMP_CODE VAL' at a location that dominates block BB or
|
|
E->DEST, then register this location as a possible insertion point
|
|
for ASSERT_EXPR <NAME, EXPR COMP_CODE VAL>.
|
|
|
|
BB, E and SI provide the exact insertion point for the new
|
|
ASSERT_EXPR. If BB is NULL, then the ASSERT_EXPR is to be inserted
|
|
on edge E. Otherwise, if E is NULL, the ASSERT_EXPR is inserted on
|
|
BB. If SI points to a COND_EXPR or a SWITCH_EXPR statement, then E
|
|
must not be NULL. */
|
|
|
|
static void
|
|
register_new_assert_for (tree name, tree expr,
|
|
enum tree_code comp_code,
|
|
tree val,
|
|
basic_block bb,
|
|
edge e,
|
|
gimple_stmt_iterator si)
|
|
{
|
|
assert_locus_t n, loc, last_loc;
|
|
basic_block dest_bb;
|
|
|
|
gcc_checking_assert (bb == NULL || e == NULL);
|
|
|
|
if (e == NULL)
|
|
gcc_checking_assert (gimple_code (gsi_stmt (si)) != GIMPLE_COND
|
|
&& gimple_code (gsi_stmt (si)) != GIMPLE_SWITCH);
|
|
|
|
/* Never build an assert comparing against an integer constant with
|
|
TREE_OVERFLOW set. This confuses our undefined overflow warning
|
|
machinery. */
|
|
if (TREE_CODE (val) == INTEGER_CST
|
|
&& TREE_OVERFLOW (val))
|
|
val = build_int_cst_wide (TREE_TYPE (val),
|
|
TREE_INT_CST_LOW (val), TREE_INT_CST_HIGH (val));
|
|
|
|
/* The new assertion A will be inserted at BB or E. We need to
|
|
determine if the new location is dominated by a previously
|
|
registered location for A. If we are doing an edge insertion,
|
|
assume that A will be inserted at E->DEST. Note that this is not
|
|
necessarily true.
|
|
|
|
If E is a critical edge, it will be split. But even if E is
|
|
split, the new block will dominate the same set of blocks that
|
|
E->DEST dominates.
|
|
|
|
The reverse, however, is not true, blocks dominated by E->DEST
|
|
will not be dominated by the new block created to split E. So,
|
|
if the insertion location is on a critical edge, we will not use
|
|
the new location to move another assertion previously registered
|
|
at a block dominated by E->DEST. */
|
|
dest_bb = (bb) ? bb : e->dest;
|
|
|
|
/* If NAME already has an ASSERT_EXPR registered for COMP_CODE and
|
|
VAL at a block dominating DEST_BB, then we don't need to insert a new
|
|
one. Similarly, if the same assertion already exists at a block
|
|
dominated by DEST_BB and the new location is not on a critical
|
|
edge, then update the existing location for the assertion (i.e.,
|
|
move the assertion up in the dominance tree).
|
|
|
|
Note, this is implemented as a simple linked list because there
|
|
should not be more than a handful of assertions registered per
|
|
name. If this becomes a performance problem, a table hashed by
|
|
COMP_CODE and VAL could be implemented. */
|
|
loc = asserts_for[SSA_NAME_VERSION (name)];
|
|
last_loc = loc;
|
|
while (loc)
|
|
{
|
|
if (loc->comp_code == comp_code
|
|
&& (loc->val == val
|
|
|| operand_equal_p (loc->val, val, 0))
|
|
&& (loc->expr == expr
|
|
|| operand_equal_p (loc->expr, expr, 0)))
|
|
{
|
|
/* If E is not a critical edge and DEST_BB
|
|
dominates the existing location for the assertion, move
|
|
the assertion up in the dominance tree by updating its
|
|
location information. */
|
|
if ((e == NULL || !EDGE_CRITICAL_P (e))
|
|
&& dominated_by_p (CDI_DOMINATORS, loc->bb, dest_bb))
|
|
{
|
|
loc->bb = dest_bb;
|
|
loc->e = e;
|
|
loc->si = si;
|
|
return;
|
|
}
|
|
}
|
|
|
|
/* Update the last node of the list and move to the next one. */
|
|
last_loc = loc;
|
|
loc = loc->next;
|
|
}
|
|
|
|
/* If we didn't find an assertion already registered for
|
|
NAME COMP_CODE VAL, add a new one at the end of the list of
|
|
assertions associated with NAME. */
|
|
n = XNEW (struct assert_locus_d);
|
|
n->bb = dest_bb;
|
|
n->e = e;
|
|
n->si = si;
|
|
n->comp_code = comp_code;
|
|
n->val = val;
|
|
n->expr = expr;
|
|
n->next = NULL;
|
|
|
|
if (last_loc)
|
|
last_loc->next = n;
|
|
else
|
|
asserts_for[SSA_NAME_VERSION (name)] = n;
|
|
|
|
bitmap_set_bit (need_assert_for, SSA_NAME_VERSION (name));
|
|
}
|
|
|
|
/* (COND_OP0 COND_CODE COND_OP1) is a predicate which uses NAME.
|
|
Extract a suitable test code and value and store them into *CODE_P and
|
|
*VAL_P so the predicate is normalized to NAME *CODE_P *VAL_P.
|
|
|
|
If no extraction was possible, return FALSE, otherwise return TRUE.
|
|
|
|
If INVERT is true, then we invert the result stored into *CODE_P. */
|
|
|
|
static bool
|
|
extract_code_and_val_from_cond_with_ops (tree name, enum tree_code cond_code,
|
|
tree cond_op0, tree cond_op1,
|
|
bool invert, enum tree_code *code_p,
|
|
tree *val_p)
|
|
{
|
|
enum tree_code comp_code;
|
|
tree val;
|
|
|
|
/* Otherwise, we have a comparison of the form NAME COMP VAL
|
|
or VAL COMP NAME. */
|
|
if (name == cond_op1)
|
|
{
|
|
/* If the predicate is of the form VAL COMP NAME, flip
|
|
COMP around because we need to register NAME as the
|
|
first operand in the predicate. */
|
|
comp_code = swap_tree_comparison (cond_code);
|
|
val = cond_op0;
|
|
}
|
|
else
|
|
{
|
|
/* The comparison is of the form NAME COMP VAL, so the
|
|
comparison code remains unchanged. */
|
|
comp_code = cond_code;
|
|
val = cond_op1;
|
|
}
|
|
|
|
/* Invert the comparison code as necessary. */
|
|
if (invert)
|
|
comp_code = invert_tree_comparison (comp_code, 0);
|
|
|
|
/* VRP does not handle float types. */
|
|
if (SCALAR_FLOAT_TYPE_P (TREE_TYPE (val)))
|
|
return false;
|
|
|
|
/* Do not register always-false predicates.
|
|
FIXME: this works around a limitation in fold() when dealing with
|
|
enumerations. Given 'enum { N1, N2 } x;', fold will not
|
|
fold 'if (x > N2)' to 'if (0)'. */
|
|
if ((comp_code == GT_EXPR || comp_code == LT_EXPR)
|
|
&& INTEGRAL_TYPE_P (TREE_TYPE (val)))
|
|
{
|
|
tree min = TYPE_MIN_VALUE (TREE_TYPE (val));
|
|
tree max = TYPE_MAX_VALUE (TREE_TYPE (val));
|
|
|
|
if (comp_code == GT_EXPR
|
|
&& (!max
|
|
|| compare_values (val, max) == 0))
|
|
return false;
|
|
|
|
if (comp_code == LT_EXPR
|
|
&& (!min
|
|
|| compare_values (val, min) == 0))
|
|
return false;
|
|
}
|
|
*code_p = comp_code;
|
|
*val_p = val;
|
|
return true;
|
|
}
|
|
|
|
/* Find out smallest RES where RES > VAL && (RES & MASK) == RES, if any
|
|
(otherwise return VAL). VAL and MASK must be zero-extended for
|
|
precision PREC. If SGNBIT is non-zero, first xor VAL with SGNBIT
|
|
(to transform signed values into unsigned) and at the end xor
|
|
SGNBIT back. */
|
|
|
|
static double_int
|
|
masked_increment (double_int val, double_int mask, double_int sgnbit,
|
|
unsigned int prec)
|
|
{
|
|
double_int bit = double_int_one, res;
|
|
unsigned int i;
|
|
|
|
val ^= sgnbit;
|
|
for (i = 0; i < prec; i++, bit += bit)
|
|
{
|
|
res = mask;
|
|
if ((res & bit).is_zero ())
|
|
continue;
|
|
res = bit - double_int_one;
|
|
res = (val + bit).and_not (res);
|
|
res &= mask;
|
|
if (res.ugt (val))
|
|
return res ^ sgnbit;
|
|
}
|
|
return val ^ sgnbit;
|
|
}
|
|
|
|
/* Try to register an edge assertion for SSA name NAME on edge E for
|
|
the condition COND contributing to the conditional jump pointed to by BSI.
|
|
Invert the condition COND if INVERT is true.
|
|
Return true if an assertion for NAME could be registered. */
|
|
|
|
static bool
|
|
register_edge_assert_for_2 (tree name, edge e, gimple_stmt_iterator bsi,
|
|
enum tree_code cond_code,
|
|
tree cond_op0, tree cond_op1, bool invert)
|
|
{
|
|
tree val;
|
|
enum tree_code comp_code;
|
|
bool retval = false;
|
|
|
|
if (!extract_code_and_val_from_cond_with_ops (name, cond_code,
|
|
cond_op0,
|
|
cond_op1,
|
|
invert, &comp_code, &val))
|
|
return false;
|
|
|
|
/* Only register an ASSERT_EXPR if NAME was found in the sub-graph
|
|
reachable from E. */
|
|
if (live_on_edge (e, name)
|
|
&& !has_single_use (name))
|
|
{
|
|
register_new_assert_for (name, name, comp_code, val, NULL, e, bsi);
|
|
retval = true;
|
|
}
|
|
|
|
/* In the case of NAME <= CST and NAME being defined as
|
|
NAME = (unsigned) NAME2 + CST2 we can assert NAME2 >= -CST2
|
|
and NAME2 <= CST - CST2. We can do the same for NAME > CST.
|
|
This catches range and anti-range tests. */
|
|
if ((comp_code == LE_EXPR
|
|
|| comp_code == GT_EXPR)
|
|
&& TREE_CODE (val) == INTEGER_CST
|
|
&& TYPE_UNSIGNED (TREE_TYPE (val)))
|
|
{
|
|
gimple def_stmt = SSA_NAME_DEF_STMT (name);
|
|
tree cst2 = NULL_TREE, name2 = NULL_TREE, name3 = NULL_TREE;
|
|
|
|
/* Extract CST2 from the (optional) addition. */
|
|
if (is_gimple_assign (def_stmt)
|
|
&& gimple_assign_rhs_code (def_stmt) == PLUS_EXPR)
|
|
{
|
|
name2 = gimple_assign_rhs1 (def_stmt);
|
|
cst2 = gimple_assign_rhs2 (def_stmt);
|
|
if (TREE_CODE (name2) == SSA_NAME
|
|
&& TREE_CODE (cst2) == INTEGER_CST)
|
|
def_stmt = SSA_NAME_DEF_STMT (name2);
|
|
}
|
|
|
|
/* Extract NAME2 from the (optional) sign-changing cast. */
|
|
if (gimple_assign_cast_p (def_stmt))
|
|
{
|
|
if (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt))
|
|
&& ! TYPE_UNSIGNED (TREE_TYPE (gimple_assign_rhs1 (def_stmt)))
|
|
&& (TYPE_PRECISION (gimple_expr_type (def_stmt))
|
|
== TYPE_PRECISION (TREE_TYPE (gimple_assign_rhs1 (def_stmt)))))
|
|
name3 = gimple_assign_rhs1 (def_stmt);
|
|
}
|
|
|
|
/* If name3 is used later, create an ASSERT_EXPR for it. */
|
|
if (name3 != NULL_TREE
|
|
&& TREE_CODE (name3) == SSA_NAME
|
|
&& (cst2 == NULL_TREE
|
|
|| TREE_CODE (cst2) == INTEGER_CST)
|
|
&& INTEGRAL_TYPE_P (TREE_TYPE (name3))
|
|
&& live_on_edge (e, name3)
|
|
&& !has_single_use (name3))
|
|
{
|
|
tree tmp;
|
|
|
|
/* Build an expression for the range test. */
|
|
tmp = build1 (NOP_EXPR, TREE_TYPE (name), name3);
|
|
if (cst2 != NULL_TREE)
|
|
tmp = build2 (PLUS_EXPR, TREE_TYPE (name), tmp, cst2);
|
|
|
|
if (dump_file)
|
|
{
|
|
fprintf (dump_file, "Adding assert for ");
|
|
print_generic_expr (dump_file, name3, 0);
|
|
fprintf (dump_file, " from ");
|
|
print_generic_expr (dump_file, tmp, 0);
|
|
fprintf (dump_file, "\n");
|
|
}
|
|
|
|
register_new_assert_for (name3, tmp, comp_code, val, NULL, e, bsi);
|
|
|
|
retval = true;
|
|
}
|
|
|
|
/* If name2 is used later, create an ASSERT_EXPR for it. */
|
|
if (name2 != NULL_TREE
|
|
&& TREE_CODE (name2) == SSA_NAME
|
|
&& TREE_CODE (cst2) == INTEGER_CST
|
|
&& INTEGRAL_TYPE_P (TREE_TYPE (name2))
|
|
&& live_on_edge (e, name2)
|
|
&& !has_single_use (name2))
|
|
{
|
|
tree tmp;
|
|
|
|
/* Build an expression for the range test. */
|
|
tmp = name2;
|
|
if (TREE_TYPE (name) != TREE_TYPE (name2))
|
|
tmp = build1 (NOP_EXPR, TREE_TYPE (name), tmp);
|
|
if (cst2 != NULL_TREE)
|
|
tmp = build2 (PLUS_EXPR, TREE_TYPE (name), tmp, cst2);
|
|
|
|
if (dump_file)
|
|
{
|
|
fprintf (dump_file, "Adding assert for ");
|
|
print_generic_expr (dump_file, name2, 0);
|
|
fprintf (dump_file, " from ");
|
|
print_generic_expr (dump_file, tmp, 0);
|
|
fprintf (dump_file, "\n");
|
|
}
|
|
|
|
register_new_assert_for (name2, tmp, comp_code, val, NULL, e, bsi);
|
|
|
|
retval = true;
|
|
}
|
|
}
|
|
|
|
/* In the case of post-in/decrement tests like if (i++) ... and uses
|
|
of the in/decremented value on the edge the extra name we want to
|
|
assert for is not on the def chain of the name compared. Instead
|
|
it is in the set of use stmts. */
|
|
if ((comp_code == NE_EXPR
|
|
|| comp_code == EQ_EXPR)
|
|
&& TREE_CODE (val) == INTEGER_CST)
|
|
{
|
|
imm_use_iterator ui;
|
|
gimple use_stmt;
|
|
FOR_EACH_IMM_USE_STMT (use_stmt, ui, name)
|
|
{
|
|
/* Cut off to use-stmts that are in the predecessor. */
|
|
if (gimple_bb (use_stmt) != e->src)
|
|
continue;
|
|
|
|
if (!is_gimple_assign (use_stmt))
|
|
continue;
|
|
|
|
enum tree_code code = gimple_assign_rhs_code (use_stmt);
|
|
if (code != PLUS_EXPR
|
|
&& code != MINUS_EXPR)
|
|
continue;
|
|
|
|
tree cst = gimple_assign_rhs2 (use_stmt);
|
|
if (TREE_CODE (cst) != INTEGER_CST)
|
|
continue;
|
|
|
|
tree name2 = gimple_assign_lhs (use_stmt);
|
|
if (live_on_edge (e, name2))
|
|
{
|
|
cst = int_const_binop (code, val, cst);
|
|
register_new_assert_for (name2, name2, comp_code, cst,
|
|
NULL, e, bsi);
|
|
retval = true;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (TREE_CODE_CLASS (comp_code) == tcc_comparison
|
|
&& TREE_CODE (val) == INTEGER_CST)
|
|
{
|
|
gimple def_stmt = SSA_NAME_DEF_STMT (name);
|
|
tree name2 = NULL_TREE, names[2], cst2 = NULL_TREE;
|
|
tree val2 = NULL_TREE;
|
|
double_int mask = double_int_zero;
|
|
unsigned int prec = TYPE_PRECISION (TREE_TYPE (val));
|
|
unsigned int nprec = prec;
|
|
enum tree_code rhs_code = ERROR_MARK;
|
|
|
|
if (is_gimple_assign (def_stmt))
|
|
rhs_code = gimple_assign_rhs_code (def_stmt);
|
|
|
|
/* Add asserts for NAME cmp CST and NAME being defined
|
|
as NAME = (int) NAME2. */
|
|
if (!TYPE_UNSIGNED (TREE_TYPE (val))
|
|
&& (comp_code == LE_EXPR || comp_code == LT_EXPR
|
|
|| comp_code == GT_EXPR || comp_code == GE_EXPR)
|
|
&& gimple_assign_cast_p (def_stmt))
|
|
{
|
|
name2 = gimple_assign_rhs1 (def_stmt);
|
|
if (CONVERT_EXPR_CODE_P (rhs_code)
|
|
&& INTEGRAL_TYPE_P (TREE_TYPE (name2))
|
|
&& TYPE_UNSIGNED (TREE_TYPE (name2))
|
|
&& prec == TYPE_PRECISION (TREE_TYPE (name2))
|
|
&& (comp_code == LE_EXPR || comp_code == GT_EXPR
|
|
|| !tree_int_cst_equal (val,
|
|
TYPE_MIN_VALUE (TREE_TYPE (val))))
|
|
&& live_on_edge (e, name2)
|
|
&& !has_single_use (name2))
|
|
{
|
|
tree tmp, cst;
|
|
enum tree_code new_comp_code = comp_code;
|
|
|
|
cst = fold_convert (TREE_TYPE (name2),
|
|
TYPE_MIN_VALUE (TREE_TYPE (val)));
|
|
/* Build an expression for the range test. */
|
|
tmp = build2 (PLUS_EXPR, TREE_TYPE (name2), name2, cst);
|
|
cst = fold_build2 (PLUS_EXPR, TREE_TYPE (name2), cst,
|
|
fold_convert (TREE_TYPE (name2), val));
|
|
if (comp_code == LT_EXPR || comp_code == GE_EXPR)
|
|
{
|
|
new_comp_code = comp_code == LT_EXPR ? LE_EXPR : GT_EXPR;
|
|
cst = fold_build2 (MINUS_EXPR, TREE_TYPE (name2), cst,
|
|
build_int_cst (TREE_TYPE (name2), 1));
|
|
}
|
|
|
|
if (dump_file)
|
|
{
|
|
fprintf (dump_file, "Adding assert for ");
|
|
print_generic_expr (dump_file, name2, 0);
|
|
fprintf (dump_file, " from ");
|
|
print_generic_expr (dump_file, tmp, 0);
|
|
fprintf (dump_file, "\n");
|
|
}
|
|
|
|
register_new_assert_for (name2, tmp, new_comp_code, cst, NULL,
|
|
e, bsi);
|
|
|
|
retval = true;
|
|
}
|
|
}
|
|
|
|
/* Add asserts for NAME cmp CST and NAME being defined as
|
|
NAME = NAME2 >> CST2.
|
|
|
|
Extract CST2 from the right shift. */
|
|
if (rhs_code == RSHIFT_EXPR)
|
|
{
|
|
name2 = gimple_assign_rhs1 (def_stmt);
|
|
cst2 = gimple_assign_rhs2 (def_stmt);
|
|
if (TREE_CODE (name2) == SSA_NAME
|
|
&& host_integerp (cst2, 1)
|
|
&& INTEGRAL_TYPE_P (TREE_TYPE (name2))
|
|
&& IN_RANGE (tree_low_cst (cst2, 1), 1, prec - 1)
|
|
&& prec <= HOST_BITS_PER_DOUBLE_INT
|
|
&& prec == GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (val)))
|
|
&& live_on_edge (e, name2)
|
|
&& !has_single_use (name2))
|
|
{
|
|
mask = double_int::mask (tree_low_cst (cst2, 1));
|
|
val2 = fold_binary (LSHIFT_EXPR, TREE_TYPE (val), val, cst2);
|
|
}
|
|
}
|
|
if (val2 != NULL_TREE
|
|
&& TREE_CODE (val2) == INTEGER_CST
|
|
&& simple_cst_equal (fold_build2 (RSHIFT_EXPR,
|
|
TREE_TYPE (val),
|
|
val2, cst2), val))
|
|
{
|
|
enum tree_code new_comp_code = comp_code;
|
|
tree tmp, new_val;
|
|
|
|
tmp = name2;
|
|
if (comp_code == EQ_EXPR || comp_code == NE_EXPR)
|
|
{
|
|
if (!TYPE_UNSIGNED (TREE_TYPE (val)))
|
|
{
|
|
tree type = build_nonstandard_integer_type (prec, 1);
|
|
tmp = build1 (NOP_EXPR, type, name2);
|
|
val2 = fold_convert (type, val2);
|
|
}
|
|
tmp = fold_build2 (MINUS_EXPR, TREE_TYPE (tmp), tmp, val2);
|
|
new_val = double_int_to_tree (TREE_TYPE (tmp), mask);
|
|
new_comp_code = comp_code == EQ_EXPR ? LE_EXPR : GT_EXPR;
|
|
}
|
|
else if (comp_code == LT_EXPR || comp_code == GE_EXPR)
|
|
new_val = val2;
|
|
else
|
|
{
|
|
double_int maxval
|
|
= double_int::max_value (prec, TYPE_UNSIGNED (TREE_TYPE (val)));
|
|
mask |= tree_to_double_int (val2);
|
|
if (mask == maxval)
|
|
new_val = NULL_TREE;
|
|
else
|
|
new_val = double_int_to_tree (TREE_TYPE (val2), mask);
|
|
}
|
|
|
|
if (new_val)
|
|
{
|
|
if (dump_file)
|
|
{
|
|
fprintf (dump_file, "Adding assert for ");
|
|
print_generic_expr (dump_file, name2, 0);
|
|
fprintf (dump_file, " from ");
|
|
print_generic_expr (dump_file, tmp, 0);
|
|
fprintf (dump_file, "\n");
|
|
}
|
|
|
|
register_new_assert_for (name2, tmp, new_comp_code, new_val,
|
|
NULL, e, bsi);
|
|
retval = true;
|
|
}
|
|
}
|
|
|
|
/* Add asserts for NAME cmp CST and NAME being defined as
|
|
NAME = NAME2 & CST2.
|
|
|
|
Extract CST2 from the and.
|
|
|
|
Also handle
|
|
NAME = (unsigned) NAME2;
|
|
casts where NAME's type is unsigned and has smaller precision
|
|
than NAME2's type as if it was NAME = NAME2 & MASK. */
|
|
names[0] = NULL_TREE;
|
|
names[1] = NULL_TREE;
|
|
cst2 = NULL_TREE;
|
|
if (rhs_code == BIT_AND_EXPR
|
|
|| (CONVERT_EXPR_CODE_P (rhs_code)
|
|
&& TREE_CODE (TREE_TYPE (val)) == INTEGER_TYPE
|
|
&& TYPE_UNSIGNED (TREE_TYPE (val))
|
|
&& TYPE_PRECISION (TREE_TYPE (gimple_assign_rhs1 (def_stmt)))
|
|
> prec
|
|
&& !retval))
|
|
{
|
|
name2 = gimple_assign_rhs1 (def_stmt);
|
|
if (rhs_code == BIT_AND_EXPR)
|
|
cst2 = gimple_assign_rhs2 (def_stmt);
|
|
else
|
|
{
|
|
cst2 = TYPE_MAX_VALUE (TREE_TYPE (val));
|
|
nprec = TYPE_PRECISION (TREE_TYPE (name2));
|
|
}
|
|
if (TREE_CODE (name2) == SSA_NAME
|
|
&& INTEGRAL_TYPE_P (TREE_TYPE (name2))
|
|
&& TREE_CODE (cst2) == INTEGER_CST
|
|
&& !integer_zerop (cst2)
|
|
&& nprec <= HOST_BITS_PER_DOUBLE_INT
|
|
&& (nprec > 1
|
|
|| TYPE_UNSIGNED (TREE_TYPE (val))))
|
|
{
|
|
gimple def_stmt2 = SSA_NAME_DEF_STMT (name2);
|
|
if (gimple_assign_cast_p (def_stmt2))
|
|
{
|
|
names[1] = gimple_assign_rhs1 (def_stmt2);
|
|
if (!CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt2))
|
|
|| !INTEGRAL_TYPE_P (TREE_TYPE (names[1]))
|
|
|| (TYPE_PRECISION (TREE_TYPE (name2))
|
|
!= TYPE_PRECISION (TREE_TYPE (names[1])))
|
|
|| !live_on_edge (e, names[1])
|
|
|| has_single_use (names[1]))
|
|
names[1] = NULL_TREE;
|
|
}
|
|
if (live_on_edge (e, name2)
|
|
&& !has_single_use (name2))
|
|
names[0] = name2;
|
|
}
|
|
}
|
|
if (names[0] || names[1])
|
|
{
|
|
double_int minv, maxv = double_int_zero, valv, cst2v;
|
|
double_int tem, sgnbit;
|
|
bool valid_p = false, valn = false, cst2n = false;
|
|
enum tree_code ccode = comp_code;
|
|
|
|
valv = tree_to_double_int (val).zext (nprec);
|
|
cst2v = tree_to_double_int (cst2).zext (nprec);
|
|
if (!TYPE_UNSIGNED (TREE_TYPE (val)))
|
|
{
|
|
valn = valv.sext (nprec).is_negative ();
|
|
cst2n = cst2v.sext (nprec).is_negative ();
|
|
}
|
|
/* If CST2 doesn't have most significant bit set,
|
|
but VAL is negative, we have comparison like
|
|
if ((x & 0x123) > -4) (always true). Just give up. */
|
|
if (!cst2n && valn)
|
|
ccode = ERROR_MARK;
|
|
if (cst2n)
|
|
sgnbit = double_int_one.llshift (nprec - 1, nprec).zext (nprec);
|
|
else
|
|
sgnbit = double_int_zero;
|
|
minv = valv & cst2v;
|
|
switch (ccode)
|
|
{
|
|
case EQ_EXPR:
|
|
/* Minimum unsigned value for equality is VAL & CST2
|
|
(should be equal to VAL, otherwise we probably should
|
|
have folded the comparison into false) and
|
|
maximum unsigned value is VAL | ~CST2. */
|
|
maxv = valv | ~cst2v;
|
|
maxv = maxv.zext (nprec);
|
|
valid_p = true;
|
|
break;
|
|
case NE_EXPR:
|
|
tem = valv | ~cst2v;
|
|
tem = tem.zext (nprec);
|
|
/* If VAL is 0, handle (X & CST2) != 0 as (X & CST2) > 0U. */
|
|
if (valv.is_zero ())
|
|
{
|
|
cst2n = false;
|
|
sgnbit = double_int_zero;
|
|
goto gt_expr;
|
|
}
|
|
/* If (VAL | ~CST2) is all ones, handle it as
|
|
(X & CST2) < VAL. */
|
|
if (tem == double_int::mask (nprec))
|
|
{
|
|
cst2n = false;
|
|
valn = false;
|
|
sgnbit = double_int_zero;
|
|
goto lt_expr;
|
|
}
|
|
if (!cst2n
|
|
&& cst2v.sext (nprec).is_negative ())
|
|
sgnbit
|
|
= double_int_one.llshift (nprec - 1, nprec).zext (nprec);
|
|
if (!sgnbit.is_zero ())
|
|
{
|
|
if (valv == sgnbit)
|
|
{
|
|
cst2n = true;
|
|
valn = true;
|
|
goto gt_expr;
|
|
}
|
|
if (tem == double_int::mask (nprec - 1))
|
|
{
|
|
cst2n = true;
|
|
goto lt_expr;
|
|
}
|
|
if (!cst2n)
|
|
sgnbit = double_int_zero;
|
|
}
|
|
break;
|
|
case GE_EXPR:
|
|
/* Minimum unsigned value for >= if (VAL & CST2) == VAL
|
|
is VAL and maximum unsigned value is ~0. For signed
|
|
comparison, if CST2 doesn't have most significant bit
|
|
set, handle it similarly. If CST2 has MSB set,
|
|
the minimum is the same, and maximum is ~0U/2. */
|
|
if (minv != valv)
|
|
{
|
|
/* If (VAL & CST2) != VAL, X & CST2 can't be equal to
|
|
VAL. */
|
|
minv = masked_increment (valv, cst2v, sgnbit, nprec);
|
|
if (minv == valv)
|
|
break;
|
|
}
|
|
maxv = double_int::mask (nprec - (cst2n ? 1 : 0));
|
|
valid_p = true;
|
|
break;
|
|
case GT_EXPR:
|
|
gt_expr:
|
|
/* Find out smallest MINV where MINV > VAL
|
|
&& (MINV & CST2) == MINV, if any. If VAL is signed and
|
|
CST2 has MSB set, compute it biased by 1 << (nprec - 1). */
|
|
minv = masked_increment (valv, cst2v, sgnbit, nprec);
|
|
if (minv == valv)
|
|
break;
|
|
maxv = double_int::mask (nprec - (cst2n ? 1 : 0));
|
|
valid_p = true;
|
|
break;
|
|
case LE_EXPR:
|
|
/* Minimum unsigned value for <= is 0 and maximum
|
|
unsigned value is VAL | ~CST2 if (VAL & CST2) == VAL.
|
|
Otherwise, find smallest VAL2 where VAL2 > VAL
|
|
&& (VAL2 & CST2) == VAL2 and use (VAL2 - 1) | ~CST2
|
|
as maximum.
|
|
For signed comparison, if CST2 doesn't have most
|
|
significant bit set, handle it similarly. If CST2 has
|
|
MSB set, the maximum is the same and minimum is INT_MIN. */
|
|
if (minv == valv)
|
|
maxv = valv;
|
|
else
|
|
{
|
|
maxv = masked_increment (valv, cst2v, sgnbit, nprec);
|
|
if (maxv == valv)
|
|
break;
|
|
maxv -= double_int_one;
|
|
}
|
|
maxv |= ~cst2v;
|
|
maxv = maxv.zext (nprec);
|
|
minv = sgnbit;
|
|
valid_p = true;
|
|
break;
|
|
case LT_EXPR:
|
|
lt_expr:
|
|
/* Minimum unsigned value for < is 0 and maximum
|
|
unsigned value is (VAL-1) | ~CST2 if (VAL & CST2) == VAL.
|
|
Otherwise, find smallest VAL2 where VAL2 > VAL
|
|
&& (VAL2 & CST2) == VAL2 and use (VAL2 - 1) | ~CST2
|
|
as maximum.
|
|
For signed comparison, if CST2 doesn't have most
|
|
significant bit set, handle it similarly. If CST2 has
|
|
MSB set, the maximum is the same and minimum is INT_MIN. */
|
|
if (minv == valv)
|
|
{
|
|
if (valv == sgnbit)
|
|
break;
|
|
maxv = valv;
|
|
}
|
|
else
|
|
{
|
|
maxv = masked_increment (valv, cst2v, sgnbit, nprec);
|
|
if (maxv == valv)
|
|
break;
|
|
}
|
|
maxv -= double_int_one;
|
|
maxv |= ~cst2v;
|
|
maxv = maxv.zext (nprec);
|
|
minv = sgnbit;
|
|
valid_p = true;
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
if (valid_p
|
|
&& (maxv - minv).zext (nprec) != double_int::mask (nprec))
|
|
{
|
|
tree tmp, new_val, type;
|
|
int i;
|
|
|
|
for (i = 0; i < 2; i++)
|
|
if (names[i])
|
|
{
|
|
double_int maxv2 = maxv;
|
|
tmp = names[i];
|
|
type = TREE_TYPE (names[i]);
|
|
if (!TYPE_UNSIGNED (type))
|
|
{
|
|
type = build_nonstandard_integer_type (nprec, 1);
|
|
tmp = build1 (NOP_EXPR, type, names[i]);
|
|
}
|
|
if (!minv.is_zero ())
|
|
{
|
|
tmp = build2 (PLUS_EXPR, type, tmp,
|
|
double_int_to_tree (type, -minv));
|
|
maxv2 = maxv - minv;
|
|
}
|
|
new_val = double_int_to_tree (type, maxv2);
|
|
|
|
if (dump_file)
|
|
{
|
|
fprintf (dump_file, "Adding assert for ");
|
|
print_generic_expr (dump_file, names[i], 0);
|
|
fprintf (dump_file, " from ");
|
|
print_generic_expr (dump_file, tmp, 0);
|
|
fprintf (dump_file, "\n");
|
|
}
|
|
|
|
register_new_assert_for (names[i], tmp, LE_EXPR,
|
|
new_val, NULL, e, bsi);
|
|
retval = true;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
return retval;
|
|
}
|
|
|
|
/* OP is an operand of a truth value expression which is known to have
|
|
a particular value. Register any asserts for OP and for any
|
|
operands in OP's defining statement.
|
|
|
|
If CODE is EQ_EXPR, then we want to register OP is zero (false),
|
|
if CODE is NE_EXPR, then we want to register OP is nonzero (true). */
|
|
|
|
static bool
|
|
register_edge_assert_for_1 (tree op, enum tree_code code,
|
|
edge e, gimple_stmt_iterator bsi)
|
|
{
|
|
bool retval = false;
|
|
gimple op_def;
|
|
tree val;
|
|
enum tree_code rhs_code;
|
|
|
|
/* We only care about SSA_NAMEs. */
|
|
if (TREE_CODE (op) != SSA_NAME)
|
|
return false;
|
|
|
|
/* We know that OP will have a zero or nonzero value. If OP is used
|
|
more than once go ahead and register an assert for OP.
|
|
|
|
The FOUND_IN_SUBGRAPH support is not helpful in this situation as
|
|
it will always be set for OP (because OP is used in a COND_EXPR in
|
|
the subgraph). */
|
|
if (!has_single_use (op))
|
|
{
|
|
val = build_int_cst (TREE_TYPE (op), 0);
|
|
register_new_assert_for (op, op, code, val, NULL, e, bsi);
|
|
retval = true;
|
|
}
|
|
|
|
/* Now look at how OP is set. If it's set from a comparison,
|
|
a truth operation or some bit operations, then we may be able
|
|
to register information about the operands of that assignment. */
|
|
op_def = SSA_NAME_DEF_STMT (op);
|
|
if (gimple_code (op_def) != GIMPLE_ASSIGN)
|
|
return retval;
|
|
|
|
rhs_code = gimple_assign_rhs_code (op_def);
|
|
|
|
if (TREE_CODE_CLASS (rhs_code) == tcc_comparison)
|
|
{
|
|
bool invert = (code == EQ_EXPR ? true : false);
|
|
tree op0 = gimple_assign_rhs1 (op_def);
|
|
tree op1 = gimple_assign_rhs2 (op_def);
|
|
|
|
if (TREE_CODE (op0) == SSA_NAME)
|
|
retval |= register_edge_assert_for_2 (op0, e, bsi, rhs_code, op0, op1,
|
|
invert);
|
|
if (TREE_CODE (op1) == SSA_NAME)
|
|
retval |= register_edge_assert_for_2 (op1, e, bsi, rhs_code, op0, op1,
|
|
invert);
|
|
}
|
|
else if ((code == NE_EXPR
|
|
&& gimple_assign_rhs_code (op_def) == BIT_AND_EXPR)
|
|
|| (code == EQ_EXPR
|
|
&& gimple_assign_rhs_code (op_def) == BIT_IOR_EXPR))
|
|
{
|
|
/* Recurse on each operand. */
|
|
retval |= register_edge_assert_for_1 (gimple_assign_rhs1 (op_def),
|
|
code, e, bsi);
|
|
retval |= register_edge_assert_for_1 (gimple_assign_rhs2 (op_def),
|
|
code, e, bsi);
|
|
}
|
|
else if (gimple_assign_rhs_code (op_def) == BIT_NOT_EXPR
|
|
&& TYPE_PRECISION (TREE_TYPE (gimple_assign_lhs (op_def))) == 1)
|
|
{
|
|
/* Recurse, flipping CODE. */
|
|
code = invert_tree_comparison (code, false);
|
|
retval |= register_edge_assert_for_1 (gimple_assign_rhs1 (op_def),
|
|
code, e, bsi);
|
|
}
|
|
else if (gimple_assign_rhs_code (op_def) == SSA_NAME)
|
|
{
|
|
/* Recurse through the copy. */
|
|
retval |= register_edge_assert_for_1 (gimple_assign_rhs1 (op_def),
|
|
code, e, bsi);
|
|
}
|
|
else if (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (op_def)))
|
|
{
|
|
/* Recurse through the type conversion. */
|
|
retval |= register_edge_assert_for_1 (gimple_assign_rhs1 (op_def),
|
|
code, e, bsi);
|
|
}
|
|
|
|
return retval;
|
|
}
|
|
|
|
/* Try to register an edge assertion for SSA name NAME on edge E for
|
|
the condition COND contributing to the conditional jump pointed to by SI.
|
|
Return true if an assertion for NAME could be registered. */
|
|
|
|
static bool
|
|
register_edge_assert_for (tree name, edge e, gimple_stmt_iterator si,
|
|
enum tree_code cond_code, tree cond_op0,
|
|
tree cond_op1)
|
|
{
|
|
tree val;
|
|
enum tree_code comp_code;
|
|
bool retval = false;
|
|
bool is_else_edge = (e->flags & EDGE_FALSE_VALUE) != 0;
|
|
|
|
/* Do not attempt to infer anything in names that flow through
|
|
abnormal edges. */
|
|
if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (name))
|
|
return false;
|
|
|
|
if (!extract_code_and_val_from_cond_with_ops (name, cond_code,
|
|
cond_op0, cond_op1,
|
|
is_else_edge,
|
|
&comp_code, &val))
|
|
return false;
|
|
|
|
/* Register ASSERT_EXPRs for name. */
|
|
retval |= register_edge_assert_for_2 (name, e, si, cond_code, cond_op0,
|
|
cond_op1, is_else_edge);
|
|
|
|
|
|
/* If COND is effectively an equality test of an SSA_NAME against
|
|
the value zero or one, then we may be able to assert values
|
|
for SSA_NAMEs which flow into COND. */
|
|
|
|
/* In the case of NAME == 1 or NAME != 0, for BIT_AND_EXPR defining
|
|
statement of NAME we can assert both operands of the BIT_AND_EXPR
|
|
have nonzero value. */
|
|
if (((comp_code == EQ_EXPR && integer_onep (val))
|
|
|| (comp_code == NE_EXPR && integer_zerop (val))))
|
|
{
|
|
gimple def_stmt = SSA_NAME_DEF_STMT (name);
|
|
|
|
if (is_gimple_assign (def_stmt)
|
|
&& gimple_assign_rhs_code (def_stmt) == BIT_AND_EXPR)
|
|
{
|
|
tree op0 = gimple_assign_rhs1 (def_stmt);
|
|
tree op1 = gimple_assign_rhs2 (def_stmt);
|
|
retval |= register_edge_assert_for_1 (op0, NE_EXPR, e, si);
|
|
retval |= register_edge_assert_for_1 (op1, NE_EXPR, e, si);
|
|
}
|
|
}
|
|
|
|
/* In the case of NAME == 0 or NAME != 1, for BIT_IOR_EXPR defining
|
|
statement of NAME we can assert both operands of the BIT_IOR_EXPR
|
|
have zero value. */
|
|
if (((comp_code == EQ_EXPR && integer_zerop (val))
|
|
|| (comp_code == NE_EXPR && integer_onep (val))))
|
|
{
|
|
gimple def_stmt = SSA_NAME_DEF_STMT (name);
|
|
|
|
/* For BIT_IOR_EXPR only if NAME == 0 both operands have
|
|
necessarily zero value, or if type-precision is one. */
|
|
if (is_gimple_assign (def_stmt)
|
|
&& (gimple_assign_rhs_code (def_stmt) == BIT_IOR_EXPR
|
|
&& (TYPE_PRECISION (TREE_TYPE (name)) == 1
|
|
|| comp_code == EQ_EXPR)))
|
|
{
|
|
tree op0 = gimple_assign_rhs1 (def_stmt);
|
|
tree op1 = gimple_assign_rhs2 (def_stmt);
|
|
retval |= register_edge_assert_for_1 (op0, EQ_EXPR, e, si);
|
|
retval |= register_edge_assert_for_1 (op1, EQ_EXPR, e, si);
|
|
}
|
|
}
|
|
|
|
return retval;
|
|
}
|
|
|
|
|
|
/* Determine whether the outgoing edges of BB should receive an
|
|
ASSERT_EXPR for each of the operands of BB's LAST statement.
|
|
The last statement of BB must be a COND_EXPR.
|
|
|
|
If any of the sub-graphs rooted at BB have an interesting use of
|
|
the predicate operands, an assert location node is added to the
|
|
list of assertions for the corresponding operands. */
|
|
|
|
static bool
|
|
find_conditional_asserts (basic_block bb, gimple last)
|
|
{
|
|
bool need_assert;
|
|
gimple_stmt_iterator bsi;
|
|
tree op;
|
|
edge_iterator ei;
|
|
edge e;
|
|
ssa_op_iter iter;
|
|
|
|
need_assert = false;
|
|
bsi = gsi_for_stmt (last);
|
|
|
|
/* Look for uses of the operands in each of the sub-graphs
|
|
rooted at BB. We need to check each of the outgoing edges
|
|
separately, so that we know what kind of ASSERT_EXPR to
|
|
insert. */
|
|
FOR_EACH_EDGE (e, ei, bb->succs)
|
|
{
|
|
if (e->dest == bb)
|
|
continue;
|
|
|
|
/* Register the necessary assertions for each operand in the
|
|
conditional predicate. */
|
|
FOR_EACH_SSA_TREE_OPERAND (op, last, iter, SSA_OP_USE)
|
|
{
|
|
need_assert |= register_edge_assert_for (op, e, bsi,
|
|
gimple_cond_code (last),
|
|
gimple_cond_lhs (last),
|
|
gimple_cond_rhs (last));
|
|
}
|
|
}
|
|
|
|
return need_assert;
|
|
}
|
|
|
|
struct case_info
|
|
{
|
|
tree expr;
|
|
basic_block bb;
|
|
};
|
|
|
|
/* Compare two case labels sorting first by the destination bb index
|
|
and then by the case value. */
|
|
|
|
static int
|
|
compare_case_labels (const void *p1, const void *p2)
|
|
{
|
|
const struct case_info *ci1 = (const struct case_info *) p1;
|
|
const struct case_info *ci2 = (const struct case_info *) p2;
|
|
int idx1 = ci1->bb->index;
|
|
int idx2 = ci2->bb->index;
|
|
|
|
if (idx1 < idx2)
|
|
return -1;
|
|
else if (idx1 == idx2)
|
|
{
|
|
/* Make sure the default label is first in a group. */
|
|
if (!CASE_LOW (ci1->expr))
|
|
return -1;
|
|
else if (!CASE_LOW (ci2->expr))
|
|
return 1;
|
|
else
|
|
return tree_int_cst_compare (CASE_LOW (ci1->expr),
|
|
CASE_LOW (ci2->expr));
|
|
}
|
|
else
|
|
return 1;
|
|
}
|
|
|
|
/* Determine whether the outgoing edges of BB should receive an
|
|
ASSERT_EXPR for each of the operands of BB's LAST statement.
|
|
The last statement of BB must be a SWITCH_EXPR.
|
|
|
|
If any of the sub-graphs rooted at BB have an interesting use of
|
|
the predicate operands, an assert location node is added to the
|
|
list of assertions for the corresponding operands. */
|
|
|
|
static bool
|
|
find_switch_asserts (basic_block bb, gimple last)
|
|
{
|
|
bool need_assert;
|
|
gimple_stmt_iterator bsi;
|
|
tree op;
|
|
edge e;
|
|
struct case_info *ci;
|
|
size_t n = gimple_switch_num_labels (last);
|
|
#if GCC_VERSION >= 4000
|
|
unsigned int idx;
|
|
#else
|
|
/* Work around GCC 3.4 bug (PR 37086). */
|
|
volatile unsigned int idx;
|
|
#endif
|
|
|
|
need_assert = false;
|
|
bsi = gsi_for_stmt (last);
|
|
op = gimple_switch_index (last);
|
|
if (TREE_CODE (op) != SSA_NAME)
|
|
return false;
|
|
|
|
/* Build a vector of case labels sorted by destination label. */
|
|
ci = XNEWVEC (struct case_info, n);
|
|
for (idx = 0; idx < n; ++idx)
|
|
{
|
|
ci[idx].expr = gimple_switch_label (last, idx);
|
|
ci[idx].bb = label_to_block (CASE_LABEL (ci[idx].expr));
|
|
}
|
|
qsort (ci, n, sizeof (struct case_info), compare_case_labels);
|
|
|
|
for (idx = 0; idx < n; ++idx)
|
|
{
|
|
tree min, max;
|
|
tree cl = ci[idx].expr;
|
|
basic_block cbb = ci[idx].bb;
|
|
|
|
min = CASE_LOW (cl);
|
|
max = CASE_HIGH (cl);
|
|
|
|
/* If there are multiple case labels with the same destination
|
|
we need to combine them to a single value range for the edge. */
|
|
if (idx + 1 < n && cbb == ci[idx + 1].bb)
|
|
{
|
|
/* Skip labels until the last of the group. */
|
|
do {
|
|
++idx;
|
|
} while (idx < n && cbb == ci[idx].bb);
|
|
--idx;
|
|
|
|
/* Pick up the maximum of the case label range. */
|
|
if (CASE_HIGH (ci[idx].expr))
|
|
max = CASE_HIGH (ci[idx].expr);
|
|
else
|
|
max = CASE_LOW (ci[idx].expr);
|
|
}
|
|
|
|
/* Nothing to do if the range includes the default label until we
|
|
can register anti-ranges. */
|
|
if (min == NULL_TREE)
|
|
continue;
|
|
|
|
/* Find the edge to register the assert expr on. */
|
|
e = find_edge (bb, cbb);
|
|
|
|
/* Register the necessary assertions for the operand in the
|
|
SWITCH_EXPR. */
|
|
need_assert |= register_edge_assert_for (op, e, bsi,
|
|
max ? GE_EXPR : EQ_EXPR,
|
|
op,
|
|
fold_convert (TREE_TYPE (op),
|
|
min));
|
|
if (max)
|
|
{
|
|
need_assert |= register_edge_assert_for (op, e, bsi, LE_EXPR,
|
|
op,
|
|
fold_convert (TREE_TYPE (op),
|
|
max));
|
|
}
|
|
}
|
|
|
|
XDELETEVEC (ci);
|
|
return need_assert;
|
|
}
|
|
|
|
|
|
/* Traverse all the statements in block BB looking for statements that
|
|
may generate useful assertions for the SSA names in their operand.
|
|
If a statement produces a useful assertion A for name N_i, then the
|
|
list of assertions already generated for N_i is scanned to
|
|
determine if A is actually needed.
|
|
|
|
If N_i already had the assertion A at a location dominating the
|
|
current location, then nothing needs to be done. Otherwise, the
|
|
new location for A is recorded instead.
|
|
|
|
1- For every statement S in BB, all the variables used by S are
|
|
added to bitmap FOUND_IN_SUBGRAPH.
|
|
|
|
2- If statement S uses an operand N in a way that exposes a known
|
|
value range for N, then if N was not already generated by an
|
|
ASSERT_EXPR, create a new assert location for N. For instance,
|
|
if N is a pointer and the statement dereferences it, we can
|
|
assume that N is not NULL.
|
|
|
|
3- COND_EXPRs are a special case of #2. We can derive range
|
|
information from the predicate but need to insert different
|
|
ASSERT_EXPRs for each of the sub-graphs rooted at the
|
|
conditional block. If the last statement of BB is a conditional
|
|
expression of the form 'X op Y', then
|
|
|
|
a) Remove X and Y from the set FOUND_IN_SUBGRAPH.
|
|
|
|
b) If the conditional is the only entry point to the sub-graph
|
|
corresponding to the THEN_CLAUSE, recurse into it. On
|
|
return, if X and/or Y are marked in FOUND_IN_SUBGRAPH, then
|
|
an ASSERT_EXPR is added for the corresponding variable.
|
|
|
|
c) Repeat step (b) on the ELSE_CLAUSE.
|
|
|
|
d) Mark X and Y in FOUND_IN_SUBGRAPH.
|
|
|
|
For instance,
|
|
|
|
if (a == 9)
|
|
b = a;
|
|
else
|
|
b = c + 1;
|
|
|
|
In this case, an assertion on the THEN clause is useful to
|
|
determine that 'a' is always 9 on that edge. However, an assertion
|
|
on the ELSE clause would be unnecessary.
|
|
|
|
4- If BB does not end in a conditional expression, then we recurse
|
|
into BB's dominator children.
|
|
|
|
At the end of the recursive traversal, every SSA name will have a
|
|
list of locations where ASSERT_EXPRs should be added. When a new
|
|
location for name N is found, it is registered by calling
|
|
register_new_assert_for. That function keeps track of all the
|
|
registered assertions to prevent adding unnecessary assertions.
|
|
For instance, if a pointer P_4 is dereferenced more than once in a
|
|
dominator tree, only the location dominating all the dereference of
|
|
P_4 will receive an ASSERT_EXPR.
|
|
|
|
If this function returns true, then it means that there are names
|
|
for which we need to generate ASSERT_EXPRs. Those assertions are
|
|
inserted by process_assert_insertions. */
|
|
|
|
static bool
|
|
find_assert_locations_1 (basic_block bb, sbitmap live)
|
|
{
|
|
gimple_stmt_iterator si;
|
|
gimple last;
|
|
bool need_assert;
|
|
|
|
need_assert = false;
|
|
last = last_stmt (bb);
|
|
|
|
/* If BB's last statement is a conditional statement involving integer
|
|
operands, determine if we need to add ASSERT_EXPRs. */
|
|
if (last
|
|
&& gimple_code (last) == GIMPLE_COND
|
|
&& !fp_predicate (last)
|
|
&& !ZERO_SSA_OPERANDS (last, SSA_OP_USE))
|
|
need_assert |= find_conditional_asserts (bb, last);
|
|
|
|
/* If BB's last statement is a switch statement involving integer
|
|
operands, determine if we need to add ASSERT_EXPRs. */
|
|
if (last
|
|
&& gimple_code (last) == GIMPLE_SWITCH
|
|
&& !ZERO_SSA_OPERANDS (last, SSA_OP_USE))
|
|
need_assert |= find_switch_asserts (bb, last);
|
|
|
|
/* Traverse all the statements in BB marking used names and looking
|
|
for statements that may infer assertions for their used operands. */
|
|
for (si = gsi_last_bb (bb); !gsi_end_p (si); gsi_prev (&si))
|
|
{
|
|
gimple stmt;
|
|
tree op;
|
|
ssa_op_iter i;
|
|
|
|
stmt = gsi_stmt (si);
|
|
|
|
if (is_gimple_debug (stmt))
|
|
continue;
|
|
|
|
/* See if we can derive an assertion for any of STMT's operands. */
|
|
FOR_EACH_SSA_TREE_OPERAND (op, stmt, i, SSA_OP_USE)
|
|
{
|
|
tree value;
|
|
enum tree_code comp_code;
|
|
|
|
/* If op is not live beyond this stmt, do not bother to insert
|
|
asserts for it. */
|
|
if (!bitmap_bit_p (live, SSA_NAME_VERSION (op)))
|
|
continue;
|
|
|
|
/* If OP is used in such a way that we can infer a value
|
|
range for it, and we don't find a previous assertion for
|
|
it, create a new assertion location node for OP. */
|
|
if (infer_value_range (stmt, op, &comp_code, &value))
|
|
{
|
|
/* If we are able to infer a nonzero value range for OP,
|
|
then walk backwards through the use-def chain to see if OP
|
|
was set via a typecast.
|
|
|
|
If so, then we can also infer a nonzero value range
|
|
for the operand of the NOP_EXPR. */
|
|
if (comp_code == NE_EXPR && integer_zerop (value))
|
|
{
|
|
tree t = op;
|
|
gimple def_stmt = SSA_NAME_DEF_STMT (t);
|
|
|
|
while (is_gimple_assign (def_stmt)
|
|
&& gimple_assign_rhs_code (def_stmt) == NOP_EXPR
|
|
&& TREE_CODE
|
|
(gimple_assign_rhs1 (def_stmt)) == SSA_NAME
|
|
&& POINTER_TYPE_P
|
|
(TREE_TYPE (gimple_assign_rhs1 (def_stmt))))
|
|
{
|
|
t = gimple_assign_rhs1 (def_stmt);
|
|
def_stmt = SSA_NAME_DEF_STMT (t);
|
|
|
|
/* Note we want to register the assert for the
|
|
operand of the NOP_EXPR after SI, not after the
|
|
conversion. */
|
|
if (! has_single_use (t))
|
|
{
|
|
register_new_assert_for (t, t, comp_code, value,
|
|
bb, NULL, si);
|
|
need_assert = true;
|
|
}
|
|
}
|
|
}
|
|
|
|
register_new_assert_for (op, op, comp_code, value, bb, NULL, si);
|
|
need_assert = true;
|
|
}
|
|
}
|
|
|
|
/* Update live. */
|
|
FOR_EACH_SSA_TREE_OPERAND (op, stmt, i, SSA_OP_USE)
|
|
bitmap_set_bit (live, SSA_NAME_VERSION (op));
|
|
FOR_EACH_SSA_TREE_OPERAND (op, stmt, i, SSA_OP_DEF)
|
|
bitmap_clear_bit (live, SSA_NAME_VERSION (op));
|
|
}
|
|
|
|
/* Traverse all PHI nodes in BB, updating live. */
|
|
for (si = gsi_start_phis (bb); !gsi_end_p(si); gsi_next (&si))
|
|
{
|
|
use_operand_p arg_p;
|
|
ssa_op_iter i;
|
|
gimple phi = gsi_stmt (si);
|
|
tree res = gimple_phi_result (phi);
|
|
|
|
if (virtual_operand_p (res))
|
|
continue;
|
|
|
|
FOR_EACH_PHI_ARG (arg_p, phi, i, SSA_OP_USE)
|
|
{
|
|
tree arg = USE_FROM_PTR (arg_p);
|
|
if (TREE_CODE (arg) == SSA_NAME)
|
|
bitmap_set_bit (live, SSA_NAME_VERSION (arg));
|
|
}
|
|
|
|
bitmap_clear_bit (live, SSA_NAME_VERSION (res));
|
|
}
|
|
|
|
return need_assert;
|
|
}
|
|
|
|
/* Do an RPO walk over the function computing SSA name liveness
|
|
on-the-fly and deciding on assert expressions to insert.
|
|
Returns true if there are assert expressions to be inserted. */
|
|
|
|
static bool
|
|
find_assert_locations (void)
|
|
{
|
|
int *rpo = XNEWVEC (int, last_basic_block);
|
|
int *bb_rpo = XNEWVEC (int, last_basic_block);
|
|
int *last_rpo = XCNEWVEC (int, last_basic_block);
|
|
int rpo_cnt, i;
|
|
bool need_asserts;
|
|
|
|
live = XCNEWVEC (sbitmap, last_basic_block);
|
|
rpo_cnt = pre_and_rev_post_order_compute (NULL, rpo, false);
|
|
for (i = 0; i < rpo_cnt; ++i)
|
|
bb_rpo[rpo[i]] = i;
|
|
|
|
need_asserts = false;
|
|
for (i = rpo_cnt - 1; i >= 0; --i)
|
|
{
|
|
basic_block bb = BASIC_BLOCK (rpo[i]);
|
|
edge e;
|
|
edge_iterator ei;
|
|
|
|
if (!live[rpo[i]])
|
|
{
|
|
live[rpo[i]] = sbitmap_alloc (num_ssa_names);
|
|
bitmap_clear (live[rpo[i]]);
|
|
}
|
|
|
|
/* Process BB and update the live information with uses in
|
|
this block. */
|
|
need_asserts |= find_assert_locations_1 (bb, live[rpo[i]]);
|
|
|
|
/* Merge liveness into the predecessor blocks and free it. */
|
|
if (!bitmap_empty_p (live[rpo[i]]))
|
|
{
|
|
int pred_rpo = i;
|
|
FOR_EACH_EDGE (e, ei, bb->preds)
|
|
{
|
|
int pred = e->src->index;
|
|
if ((e->flags & EDGE_DFS_BACK) || pred == ENTRY_BLOCK)
|
|
continue;
|
|
|
|
if (!live[pred])
|
|
{
|
|
live[pred] = sbitmap_alloc (num_ssa_names);
|
|
bitmap_clear (live[pred]);
|
|
}
|
|
bitmap_ior (live[pred], live[pred], live[rpo[i]]);
|
|
|
|
if (bb_rpo[pred] < pred_rpo)
|
|
pred_rpo = bb_rpo[pred];
|
|
}
|
|
|
|
/* Record the RPO number of the last visited block that needs
|
|
live information from this block. */
|
|
last_rpo[rpo[i]] = pred_rpo;
|
|
}
|
|
else
|
|
{
|
|
sbitmap_free (live[rpo[i]]);
|
|
live[rpo[i]] = NULL;
|
|
}
|
|
|
|
/* We can free all successors live bitmaps if all their
|
|
predecessors have been visited already. */
|
|
FOR_EACH_EDGE (e, ei, bb->succs)
|
|
if (last_rpo[e->dest->index] == i
|
|
&& live[e->dest->index])
|
|
{
|
|
sbitmap_free (live[e->dest->index]);
|
|
live[e->dest->index] = NULL;
|
|
}
|
|
}
|
|
|
|
XDELETEVEC (rpo);
|
|
XDELETEVEC (bb_rpo);
|
|
XDELETEVEC (last_rpo);
|
|
for (i = 0; i < last_basic_block; ++i)
|
|
if (live[i])
|
|
sbitmap_free (live[i]);
|
|
XDELETEVEC (live);
|
|
|
|
return need_asserts;
|
|
}
|
|
|
|
/* Create an ASSERT_EXPR for NAME and insert it in the location
|
|
indicated by LOC. Return true if we made any edge insertions. */
|
|
|
|
static bool
|
|
process_assert_insertions_for (tree name, assert_locus_t loc)
|
|
{
|
|
/* Build the comparison expression NAME_i COMP_CODE VAL. */
|
|
gimple stmt;
|
|
tree cond;
|
|
gimple assert_stmt;
|
|
edge_iterator ei;
|
|
edge e;
|
|
|
|
/* If we have X <=> X do not insert an assert expr for that. */
|
|
if (loc->expr == loc->val)
|
|
return false;
|
|
|
|
cond = build2 (loc->comp_code, boolean_type_node, loc->expr, loc->val);
|
|
assert_stmt = build_assert_expr_for (cond, name);
|
|
if (loc->e)
|
|
{
|
|
/* We have been asked to insert the assertion on an edge. This
|
|
is used only by COND_EXPR and SWITCH_EXPR assertions. */
|
|
gcc_checking_assert (gimple_code (gsi_stmt (loc->si)) == GIMPLE_COND
|
|
|| (gimple_code (gsi_stmt (loc->si))
|
|
== GIMPLE_SWITCH));
|
|
|
|
gsi_insert_on_edge (loc->e, assert_stmt);
|
|
return true;
|
|
}
|
|
|
|
/* Otherwise, we can insert right after LOC->SI iff the
|
|
statement must not be the last statement in the block. */
|
|
stmt = gsi_stmt (loc->si);
|
|
if (!stmt_ends_bb_p (stmt))
|
|
{
|
|
gsi_insert_after (&loc->si, assert_stmt, GSI_SAME_STMT);
|
|
return false;
|
|
}
|
|
|
|
/* If STMT must be the last statement in BB, we can only insert new
|
|
assertions on the non-abnormal edge out of BB. Note that since
|
|
STMT is not control flow, there may only be one non-abnormal edge
|
|
out of BB. */
|
|
FOR_EACH_EDGE (e, ei, loc->bb->succs)
|
|
if (!(e->flags & EDGE_ABNORMAL))
|
|
{
|
|
gsi_insert_on_edge (e, assert_stmt);
|
|
return true;
|
|
}
|
|
|
|
gcc_unreachable ();
|
|
}
|
|
|
|
|
|
/* Process all the insertions registered for every name N_i registered
|
|
in NEED_ASSERT_FOR. The list of assertions to be inserted are
|
|
found in ASSERTS_FOR[i]. */
|
|
|
|
static void
|
|
process_assert_insertions (void)
|
|
{
|
|
unsigned i;
|
|
bitmap_iterator bi;
|
|
bool update_edges_p = false;
|
|
int num_asserts = 0;
|
|
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
dump_all_asserts (dump_file);
|
|
|
|
EXECUTE_IF_SET_IN_BITMAP (need_assert_for, 0, i, bi)
|
|
{
|
|
assert_locus_t loc = asserts_for[i];
|
|
gcc_assert (loc);
|
|
|
|
while (loc)
|
|
{
|
|
assert_locus_t next = loc->next;
|
|
update_edges_p |= process_assert_insertions_for (ssa_name (i), loc);
|
|
free (loc);
|
|
loc = next;
|
|
num_asserts++;
|
|
}
|
|
}
|
|
|
|
if (update_edges_p)
|
|
gsi_commit_edge_inserts ();
|
|
|
|
statistics_counter_event (cfun, "Number of ASSERT_EXPR expressions inserted",
|
|
num_asserts);
|
|
}
|
|
|
|
|
|
/* Traverse the flowgraph looking for conditional jumps to insert range
|
|
expressions. These range expressions are meant to provide information
|
|
to optimizations that need to reason in terms of value ranges. They
|
|
will not be expanded into RTL. For instance, given:
|
|
|
|
x = ...
|
|
y = ...
|
|
if (x < y)
|
|
y = x - 2;
|
|
else
|
|
x = y + 3;
|
|
|
|
this pass will transform the code into:
|
|
|
|
x = ...
|
|
y = ...
|
|
if (x < y)
|
|
{
|
|
x = ASSERT_EXPR <x, x < y>
|
|
y = x - 2
|
|
}
|
|
else
|
|
{
|
|
y = ASSERT_EXPR <y, x <= y>
|
|
x = y + 3
|
|
}
|
|
|
|
The idea is that once copy and constant propagation have run, other
|
|
optimizations will be able to determine what ranges of values can 'x'
|
|
take in different paths of the code, simply by checking the reaching
|
|
definition of 'x'. */
|
|
|
|
static void
|
|
insert_range_assertions (void)
|
|
{
|
|
need_assert_for = BITMAP_ALLOC (NULL);
|
|
asserts_for = XCNEWVEC (assert_locus_t, num_ssa_names);
|
|
|
|
calculate_dominance_info (CDI_DOMINATORS);
|
|
|
|
if (find_assert_locations ())
|
|
{
|
|
process_assert_insertions ();
|
|
update_ssa (TODO_update_ssa_no_phi);
|
|
}
|
|
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
{
|
|
fprintf (dump_file, "\nSSA form after inserting ASSERT_EXPRs\n");
|
|
dump_function_to_file (current_function_decl, dump_file, dump_flags);
|
|
}
|
|
|
|
free (asserts_for);
|
|
BITMAP_FREE (need_assert_for);
|
|
}
|
|
|
|
/* Checks one ARRAY_REF in REF, located at LOCUS. Ignores flexible arrays
|
|
and "struct" hacks. If VRP can determine that the
|
|
array subscript is a constant, check if it is outside valid
|
|
range. If the array subscript is a RANGE, warn if it is
|
|
non-overlapping with valid range.
|
|
IGNORE_OFF_BY_ONE is true if the ARRAY_REF is inside a ADDR_EXPR. */
|
|
|
|
static void
|
|
check_array_ref (location_t location, tree ref, bool ignore_off_by_one)
|
|
{
|
|
value_range_t* vr = NULL;
|
|
tree low_sub, up_sub;
|
|
tree low_bound, up_bound, up_bound_p1;
|
|
tree base;
|
|
|
|
if (TREE_NO_WARNING (ref))
|
|
return;
|
|
|
|
low_sub = up_sub = TREE_OPERAND (ref, 1);
|
|
up_bound = array_ref_up_bound (ref);
|
|
|
|
/* Can not check flexible arrays. */
|
|
if (!up_bound
|
|
|| TREE_CODE (up_bound) != INTEGER_CST)
|
|
return;
|
|
|
|
/* Accesses to trailing arrays via pointers may access storage
|
|
beyond the types array bounds. */
|
|
base = get_base_address (ref);
|
|
if (base && TREE_CODE (base) == MEM_REF)
|
|
{
|
|
tree cref, next = NULL_TREE;
|
|
|
|
if (TREE_CODE (TREE_OPERAND (ref, 0)) != COMPONENT_REF)
|
|
return;
|
|
|
|
cref = TREE_OPERAND (ref, 0);
|
|
if (TREE_CODE (TREE_TYPE (TREE_OPERAND (cref, 0))) == RECORD_TYPE)
|
|
for (next = DECL_CHAIN (TREE_OPERAND (cref, 1));
|
|
next && TREE_CODE (next) != FIELD_DECL;
|
|
next = DECL_CHAIN (next))
|
|
;
|
|
|
|
/* If this is the last field in a struct type or a field in a
|
|
union type do not warn. */
|
|
if (!next)
|
|
return;
|
|
}
|
|
|
|
low_bound = array_ref_low_bound (ref);
|
|
up_bound_p1 = int_const_binop (PLUS_EXPR, up_bound, integer_one_node);
|
|
|
|
if (TREE_CODE (low_sub) == SSA_NAME)
|
|
{
|
|
vr = get_value_range (low_sub);
|
|
if (vr->type == VR_RANGE || vr->type == VR_ANTI_RANGE)
|
|
{
|
|
low_sub = vr->type == VR_RANGE ? vr->max : vr->min;
|
|
up_sub = vr->type == VR_RANGE ? vr->min : vr->max;
|
|
}
|
|
}
|
|
|
|
if (vr && vr->type == VR_ANTI_RANGE)
|
|
{
|
|
if (TREE_CODE (up_sub) == INTEGER_CST
|
|
&& tree_int_cst_lt (up_bound, up_sub)
|
|
&& TREE_CODE (low_sub) == INTEGER_CST
|
|
&& tree_int_cst_lt (low_sub, low_bound))
|
|
{
|
|
warning_at (location, OPT_Warray_bounds,
|
|
"array subscript is outside array bounds");
|
|
TREE_NO_WARNING (ref) = 1;
|
|
}
|
|
}
|
|
else if (TREE_CODE (up_sub) == INTEGER_CST
|
|
&& (ignore_off_by_one
|
|
? (tree_int_cst_lt (up_bound, up_sub)
|
|
&& !tree_int_cst_equal (up_bound_p1, up_sub))
|
|
: (tree_int_cst_lt (up_bound, up_sub)
|
|
|| tree_int_cst_equal (up_bound_p1, up_sub))))
|
|
{
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
{
|
|
fprintf (dump_file, "Array bound warning for ");
|
|
dump_generic_expr (MSG_NOTE, TDF_SLIM, ref);
|
|
}
|
|
warning_at (location, OPT_Warray_bounds,
|
|
"array subscript is above array bounds");
|
|
TREE_NO_WARNING (ref) = 1;
|
|
}
|
|
else if (TREE_CODE (low_sub) == INTEGER_CST
|
|
&& tree_int_cst_lt (low_sub, low_bound))
|
|
{
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
{
|
|
fprintf (dump_file, "Array bound warning for ");
|
|
dump_generic_expr (MSG_NOTE, TDF_SLIM, ref);
|
|
}
|
|
warning_at (location, OPT_Warray_bounds,
|
|
"array subscript is below array bounds");
|
|
TREE_NO_WARNING (ref) = 1;
|
|
}
|
|
}
|
|
|
|
/* Searches if the expr T, located at LOCATION computes
|
|
address of an ARRAY_REF, and call check_array_ref on it. */
|
|
|
|
static void
|
|
search_for_addr_array (tree t, location_t location)
|
|
{
|
|
while (TREE_CODE (t) == SSA_NAME)
|
|
{
|
|
gimple g = SSA_NAME_DEF_STMT (t);
|
|
|
|
if (gimple_code (g) != GIMPLE_ASSIGN)
|
|
return;
|
|
|
|
if (get_gimple_rhs_class (gimple_assign_rhs_code (g))
|
|
!= GIMPLE_SINGLE_RHS)
|
|
return;
|
|
|
|
t = gimple_assign_rhs1 (g);
|
|
}
|
|
|
|
|
|
/* We are only interested in addresses of ARRAY_REF's. */
|
|
if (TREE_CODE (t) != ADDR_EXPR)
|
|
return;
|
|
|
|
/* Check each ARRAY_REFs in the reference chain. */
|
|
do
|
|
{
|
|
if (TREE_CODE (t) == ARRAY_REF)
|
|
check_array_ref (location, t, true /*ignore_off_by_one*/);
|
|
|
|
t = TREE_OPERAND (t, 0);
|
|
}
|
|
while (handled_component_p (t));
|
|
|
|
if (TREE_CODE (t) == MEM_REF
|
|
&& TREE_CODE (TREE_OPERAND (t, 0)) == ADDR_EXPR
|
|
&& !TREE_NO_WARNING (t))
|
|
{
|
|
tree tem = TREE_OPERAND (TREE_OPERAND (t, 0), 0);
|
|
tree low_bound, up_bound, el_sz;
|
|
double_int idx;
|
|
if (TREE_CODE (TREE_TYPE (tem)) != ARRAY_TYPE
|
|
|| TREE_CODE (TREE_TYPE (TREE_TYPE (tem))) == ARRAY_TYPE
|
|
|| !TYPE_DOMAIN (TREE_TYPE (tem)))
|
|
return;
|
|
|
|
low_bound = TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (tem)));
|
|
up_bound = TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (tem)));
|
|
el_sz = TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (tem)));
|
|
if (!low_bound
|
|
|| TREE_CODE (low_bound) != INTEGER_CST
|
|
|| !up_bound
|
|
|| TREE_CODE (up_bound) != INTEGER_CST
|
|
|| !el_sz
|
|
|| TREE_CODE (el_sz) != INTEGER_CST)
|
|
return;
|
|
|
|
idx = mem_ref_offset (t);
|
|
idx = idx.sdiv (tree_to_double_int (el_sz), TRUNC_DIV_EXPR);
|
|
if (idx.slt (double_int_zero))
|
|
{
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
{
|
|
fprintf (dump_file, "Array bound warning for ");
|
|
dump_generic_expr (MSG_NOTE, TDF_SLIM, t);
|
|
}
|
|
warning_at (location, OPT_Warray_bounds,
|
|
"array subscript is below array bounds");
|
|
TREE_NO_WARNING (t) = 1;
|
|
}
|
|
else if (idx.sgt (tree_to_double_int (up_bound)
|
|
- tree_to_double_int (low_bound)
|
|
+ double_int_one))
|
|
{
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
{
|
|
fprintf (dump_file, "Array bound warning for ");
|
|
dump_generic_expr (MSG_NOTE, TDF_SLIM, t);
|
|
}
|
|
warning_at (location, OPT_Warray_bounds,
|
|
"array subscript is above array bounds");
|
|
TREE_NO_WARNING (t) = 1;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* walk_tree() callback that checks if *TP is
|
|
an ARRAY_REF inside an ADDR_EXPR (in which an array
|
|
subscript one outside the valid range is allowed). Call
|
|
check_array_ref for each ARRAY_REF found. The location is
|
|
passed in DATA. */
|
|
|
|
static tree
|
|
check_array_bounds (tree *tp, int *walk_subtree, void *data)
|
|
{
|
|
tree t = *tp;
|
|
struct walk_stmt_info *wi = (struct walk_stmt_info *) data;
|
|
location_t location;
|
|
|
|
if (EXPR_HAS_LOCATION (t))
|
|
location = EXPR_LOCATION (t);
|
|
else
|
|
{
|
|
location_t *locp = (location_t *) wi->info;
|
|
location = *locp;
|
|
}
|
|
|
|
*walk_subtree = TRUE;
|
|
|
|
if (TREE_CODE (t) == ARRAY_REF)
|
|
check_array_ref (location, t, false /*ignore_off_by_one*/);
|
|
|
|
if (TREE_CODE (t) == MEM_REF
|
|
|| (TREE_CODE (t) == RETURN_EXPR && TREE_OPERAND (t, 0)))
|
|
search_for_addr_array (TREE_OPERAND (t, 0), location);
|
|
|
|
if (TREE_CODE (t) == ADDR_EXPR)
|
|
*walk_subtree = FALSE;
|
|
|
|
return NULL_TREE;
|
|
}
|
|
|
|
/* Walk over all statements of all reachable BBs and call check_array_bounds
|
|
on them. */
|
|
|
|
static void
|
|
check_all_array_refs (void)
|
|
{
|
|
basic_block bb;
|
|
gimple_stmt_iterator si;
|
|
|
|
FOR_EACH_BB (bb)
|
|
{
|
|
edge_iterator ei;
|
|
edge e;
|
|
bool executable = false;
|
|
|
|
/* Skip blocks that were found to be unreachable. */
|
|
FOR_EACH_EDGE (e, ei, bb->preds)
|
|
executable |= !!(e->flags & EDGE_EXECUTABLE);
|
|
if (!executable)
|
|
continue;
|
|
|
|
for (si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si))
|
|
{
|
|
gimple stmt = gsi_stmt (si);
|
|
struct walk_stmt_info wi;
|
|
if (!gimple_has_location (stmt))
|
|
continue;
|
|
|
|
if (is_gimple_call (stmt))
|
|
{
|
|
size_t i;
|
|
size_t n = gimple_call_num_args (stmt);
|
|
for (i = 0; i < n; i++)
|
|
{
|
|
tree arg = gimple_call_arg (stmt, i);
|
|
search_for_addr_array (arg, gimple_location (stmt));
|
|
}
|
|
}
|
|
else
|
|
{
|
|
memset (&wi, 0, sizeof (wi));
|
|
wi.info = CONST_CAST (void *, (const void *)
|
|
gimple_location_ptr (stmt));
|
|
|
|
walk_gimple_op (gsi_stmt (si),
|
|
check_array_bounds,
|
|
&wi);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Convert range assertion expressions into the implied copies and
|
|
copy propagate away the copies. Doing the trivial copy propagation
|
|
here avoids the need to run the full copy propagation pass after
|
|
VRP.
|
|
|
|
FIXME, this will eventually lead to copy propagation removing the
|
|
names that had useful range information attached to them. For
|
|
instance, if we had the assertion N_i = ASSERT_EXPR <N_j, N_j > 3>,
|
|
then N_i will have the range [3, +INF].
|
|
|
|
However, by converting the assertion into the implied copy
|
|
operation N_i = N_j, we will then copy-propagate N_j into the uses
|
|
of N_i and lose the range information. We may want to hold on to
|
|
ASSERT_EXPRs a little while longer as the ranges could be used in
|
|
things like jump threading.
|
|
|
|
The problem with keeping ASSERT_EXPRs around is that passes after
|
|
VRP need to handle them appropriately.
|
|
|
|
Another approach would be to make the range information a first
|
|
class property of the SSA_NAME so that it can be queried from
|
|
any pass. This is made somewhat more complex by the need for
|
|
multiple ranges to be associated with one SSA_NAME. */
|
|
|
|
static void
|
|
remove_range_assertions (void)
|
|
{
|
|
basic_block bb;
|
|
gimple_stmt_iterator si;
|
|
|
|
/* Note that the BSI iterator bump happens at the bottom of the
|
|
loop and no bump is necessary if we're removing the statement
|
|
referenced by the current BSI. */
|
|
FOR_EACH_BB (bb)
|
|
for (si = gsi_start_bb (bb); !gsi_end_p (si);)
|
|
{
|
|
gimple stmt = gsi_stmt (si);
|
|
gimple use_stmt;
|
|
|
|
if (is_gimple_assign (stmt)
|
|
&& gimple_assign_rhs_code (stmt) == ASSERT_EXPR)
|
|
{
|
|
tree rhs = gimple_assign_rhs1 (stmt);
|
|
tree var;
|
|
tree cond = fold (ASSERT_EXPR_COND (rhs));
|
|
use_operand_p use_p;
|
|
imm_use_iterator iter;
|
|
|
|
gcc_assert (cond != boolean_false_node);
|
|
|
|
/* Propagate the RHS into every use of the LHS. */
|
|
var = ASSERT_EXPR_VAR (rhs);
|
|
FOR_EACH_IMM_USE_STMT (use_stmt, iter,
|
|
gimple_assign_lhs (stmt))
|
|
FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
|
|
{
|
|
SET_USE (use_p, var);
|
|
gcc_assert (TREE_CODE (var) == SSA_NAME);
|
|
}
|
|
|
|
/* And finally, remove the copy, it is not needed. */
|
|
gsi_remove (&si, true);
|
|
release_defs (stmt);
|
|
}
|
|
else
|
|
gsi_next (&si);
|
|
}
|
|
}
|
|
|
|
|
|
/* Return true if STMT is interesting for VRP. */
|
|
|
|
static bool
|
|
stmt_interesting_for_vrp (gimple stmt)
|
|
{
|
|
if (gimple_code (stmt) == GIMPLE_PHI)
|
|
{
|
|
tree res = gimple_phi_result (stmt);
|
|
return (!virtual_operand_p (res)
|
|
&& (INTEGRAL_TYPE_P (TREE_TYPE (res))
|
|
|| POINTER_TYPE_P (TREE_TYPE (res))));
|
|
}
|
|
else if (is_gimple_assign (stmt) || is_gimple_call (stmt))
|
|
{
|
|
tree lhs = gimple_get_lhs (stmt);
|
|
|
|
/* In general, assignments with virtual operands are not useful
|
|
for deriving ranges, with the obvious exception of calls to
|
|
builtin functions. */
|
|
if (lhs && TREE_CODE (lhs) == SSA_NAME
|
|
&& (INTEGRAL_TYPE_P (TREE_TYPE (lhs))
|
|
|| POINTER_TYPE_P (TREE_TYPE (lhs)))
|
|
&& ((is_gimple_call (stmt)
|
|
&& gimple_call_fndecl (stmt) != NULL_TREE
|
|
&& DECL_BUILT_IN (gimple_call_fndecl (stmt)))
|
|
|| !gimple_vuse (stmt)))
|
|
return true;
|
|
}
|
|
else if (gimple_code (stmt) == GIMPLE_COND
|
|
|| gimple_code (stmt) == GIMPLE_SWITCH)
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
|
|
/* Initialize local data structures for VRP. */
|
|
|
|
static void
|
|
vrp_initialize (void)
|
|
{
|
|
basic_block bb;
|
|
|
|
values_propagated = false;
|
|
num_vr_values = num_ssa_names;
|
|
vr_value = XCNEWVEC (value_range_t *, num_vr_values);
|
|
vr_phi_edge_counts = XCNEWVEC (int, num_ssa_names);
|
|
|
|
FOR_EACH_BB (bb)
|
|
{
|
|
gimple_stmt_iterator si;
|
|
|
|
for (si = gsi_start_phis (bb); !gsi_end_p (si); gsi_next (&si))
|
|
{
|
|
gimple phi = gsi_stmt (si);
|
|
if (!stmt_interesting_for_vrp (phi))
|
|
{
|
|
tree lhs = PHI_RESULT (phi);
|
|
set_value_range_to_varying (get_value_range (lhs));
|
|
prop_set_simulate_again (phi, false);
|
|
}
|
|
else
|
|
prop_set_simulate_again (phi, true);
|
|
}
|
|
|
|
for (si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si))
|
|
{
|
|
gimple stmt = gsi_stmt (si);
|
|
|
|
/* If the statement is a control insn, then we do not
|
|
want to avoid simulating the statement once. Failure
|
|
to do so means that those edges will never get added. */
|
|
if (stmt_ends_bb_p (stmt))
|
|
prop_set_simulate_again (stmt, true);
|
|
else if (!stmt_interesting_for_vrp (stmt))
|
|
{
|
|
ssa_op_iter i;
|
|
tree def;
|
|
FOR_EACH_SSA_TREE_OPERAND (def, stmt, i, SSA_OP_DEF)
|
|
set_value_range_to_varying (get_value_range (def));
|
|
prop_set_simulate_again (stmt, false);
|
|
}
|
|
else
|
|
prop_set_simulate_again (stmt, true);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Return the singleton value-range for NAME or NAME. */
|
|
|
|
static inline tree
|
|
vrp_valueize (tree name)
|
|
{
|
|
if (TREE_CODE (name) == SSA_NAME)
|
|
{
|
|
value_range_t *vr = get_value_range (name);
|
|
if (vr->type == VR_RANGE
|
|
&& (vr->min == vr->max
|
|
|| operand_equal_p (vr->min, vr->max, 0)))
|
|
return vr->min;
|
|
}
|
|
return name;
|
|
}
|
|
|
|
/* Visit assignment STMT. If it produces an interesting range, record
|
|
the SSA name in *OUTPUT_P. */
|
|
|
|
static enum ssa_prop_result
|
|
vrp_visit_assignment_or_call (gimple stmt, tree *output_p)
|
|
{
|
|
tree def, lhs;
|
|
ssa_op_iter iter;
|
|
enum gimple_code code = gimple_code (stmt);
|
|
lhs = gimple_get_lhs (stmt);
|
|
|
|
/* We only keep track of ranges in integral and pointer types. */
|
|
if (TREE_CODE (lhs) == SSA_NAME
|
|
&& ((INTEGRAL_TYPE_P (TREE_TYPE (lhs))
|
|
/* It is valid to have NULL MIN/MAX values on a type. See
|
|
build_range_type. */
|
|
&& TYPE_MIN_VALUE (TREE_TYPE (lhs))
|
|
&& TYPE_MAX_VALUE (TREE_TYPE (lhs)))
|
|
|| POINTER_TYPE_P (TREE_TYPE (lhs))))
|
|
{
|
|
value_range_t new_vr = VR_INITIALIZER;
|
|
|
|
/* Try folding the statement to a constant first. */
|
|
tree tem = gimple_fold_stmt_to_constant (stmt, vrp_valueize);
|
|
if (tem && !is_overflow_infinity (tem))
|
|
set_value_range (&new_vr, VR_RANGE, tem, tem, NULL);
|
|
/* Then dispatch to value-range extracting functions. */
|
|
else if (code == GIMPLE_CALL)
|
|
extract_range_basic (&new_vr, stmt);
|
|
else
|
|
extract_range_from_assignment (&new_vr, stmt);
|
|
|
|
if (update_value_range (lhs, &new_vr))
|
|
{
|
|
*output_p = lhs;
|
|
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
{
|
|
fprintf (dump_file, "Found new range for ");
|
|
print_generic_expr (dump_file, lhs, 0);
|
|
fprintf (dump_file, ": ");
|
|
dump_value_range (dump_file, &new_vr);
|
|
fprintf (dump_file, "\n\n");
|
|
}
|
|
|
|
if (new_vr.type == VR_VARYING)
|
|
return SSA_PROP_VARYING;
|
|
|
|
return SSA_PROP_INTERESTING;
|
|
}
|
|
|
|
return SSA_PROP_NOT_INTERESTING;
|
|
}
|
|
|
|
/* Every other statement produces no useful ranges. */
|
|
FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_DEF)
|
|
set_value_range_to_varying (get_value_range (def));
|
|
|
|
return SSA_PROP_VARYING;
|
|
}
|
|
|
|
/* Helper that gets the value range of the SSA_NAME with version I
|
|
or a symbolic range containing the SSA_NAME only if the value range
|
|
is varying or undefined. */
|
|
|
|
static inline value_range_t
|
|
get_vr_for_comparison (int i)
|
|
{
|
|
value_range_t vr = *get_value_range (ssa_name (i));
|
|
|
|
/* If name N_i does not have a valid range, use N_i as its own
|
|
range. This allows us to compare against names that may
|
|
have N_i in their ranges. */
|
|
if (vr.type == VR_VARYING || vr.type == VR_UNDEFINED)
|
|
{
|
|
vr.type = VR_RANGE;
|
|
vr.min = ssa_name (i);
|
|
vr.max = ssa_name (i);
|
|
}
|
|
|
|
return vr;
|
|
}
|
|
|
|
/* Compare all the value ranges for names equivalent to VAR with VAL
|
|
using comparison code COMP. Return the same value returned by
|
|
compare_range_with_value, including the setting of
|
|
*STRICT_OVERFLOW_P. */
|
|
|
|
static tree
|
|
compare_name_with_value (enum tree_code comp, tree var, tree val,
|
|
bool *strict_overflow_p)
|
|
{
|
|
bitmap_iterator bi;
|
|
unsigned i;
|
|
bitmap e;
|
|
tree retval, t;
|
|
int used_strict_overflow;
|
|
bool sop;
|
|
value_range_t equiv_vr;
|
|
|
|
/* Get the set of equivalences for VAR. */
|
|
e = get_value_range (var)->equiv;
|
|
|
|
/* Start at -1. Set it to 0 if we do a comparison without relying
|
|
on overflow, or 1 if all comparisons rely on overflow. */
|
|
used_strict_overflow = -1;
|
|
|
|
/* Compare vars' value range with val. */
|
|
equiv_vr = get_vr_for_comparison (SSA_NAME_VERSION (var));
|
|
sop = false;
|
|
retval = compare_range_with_value (comp, &equiv_vr, val, &sop);
|
|
if (retval)
|
|
used_strict_overflow = sop ? 1 : 0;
|
|
|
|
/* If the equiv set is empty we have done all work we need to do. */
|
|
if (e == NULL)
|
|
{
|
|
if (retval
|
|
&& used_strict_overflow > 0)
|
|
*strict_overflow_p = true;
|
|
return retval;
|
|
}
|
|
|
|
EXECUTE_IF_SET_IN_BITMAP (e, 0, i, bi)
|
|
{
|
|
equiv_vr = get_vr_for_comparison (i);
|
|
sop = false;
|
|
t = compare_range_with_value (comp, &equiv_vr, val, &sop);
|
|
if (t)
|
|
{
|
|
/* If we get different answers from different members
|
|
of the equivalence set this check must be in a dead
|
|
code region. Folding it to a trap representation
|
|
would be correct here. For now just return don't-know. */
|
|
if (retval != NULL
|
|
&& t != retval)
|
|
{
|
|
retval = NULL_TREE;
|
|
break;
|
|
}
|
|
retval = t;
|
|
|
|
if (!sop)
|
|
used_strict_overflow = 0;
|
|
else if (used_strict_overflow < 0)
|
|
used_strict_overflow = 1;
|
|
}
|
|
}
|
|
|
|
if (retval
|
|
&& used_strict_overflow > 0)
|
|
*strict_overflow_p = true;
|
|
|
|
return retval;
|
|
}
|
|
|
|
|
|
/* Given a comparison code COMP and names N1 and N2, compare all the
|
|
ranges equivalent to N1 against all the ranges equivalent to N2
|
|
to determine the value of N1 COMP N2. Return the same value
|
|
returned by compare_ranges. Set *STRICT_OVERFLOW_P to indicate
|
|
whether we relied on an overflow infinity in the comparison. */
|
|
|
|
|
|
static tree
|
|
compare_names (enum tree_code comp, tree n1, tree n2,
|
|
bool *strict_overflow_p)
|
|
{
|
|
tree t, retval;
|
|
bitmap e1, e2;
|
|
bitmap_iterator bi1, bi2;
|
|
unsigned i1, i2;
|
|
int used_strict_overflow;
|
|
static bitmap_obstack *s_obstack = NULL;
|
|
static bitmap s_e1 = NULL, s_e2 = NULL;
|
|
|
|
/* Compare the ranges of every name equivalent to N1 against the
|
|
ranges of every name equivalent to N2. */
|
|
e1 = get_value_range (n1)->equiv;
|
|
e2 = get_value_range (n2)->equiv;
|
|
|
|
/* Use the fake bitmaps if e1 or e2 are not available. */
|
|
if (s_obstack == NULL)
|
|
{
|
|
s_obstack = XNEW (bitmap_obstack);
|
|
bitmap_obstack_initialize (s_obstack);
|
|
s_e1 = BITMAP_ALLOC (s_obstack);
|
|
s_e2 = BITMAP_ALLOC (s_obstack);
|
|
}
|
|
if (e1 == NULL)
|
|
e1 = s_e1;
|
|
if (e2 == NULL)
|
|
e2 = s_e2;
|
|
|
|
/* Add N1 and N2 to their own set of equivalences to avoid
|
|
duplicating the body of the loop just to check N1 and N2
|
|
ranges. */
|
|
bitmap_set_bit (e1, SSA_NAME_VERSION (n1));
|
|
bitmap_set_bit (e2, SSA_NAME_VERSION (n2));
|
|
|
|
/* If the equivalence sets have a common intersection, then the two
|
|
names can be compared without checking their ranges. */
|
|
if (bitmap_intersect_p (e1, e2))
|
|
{
|
|
bitmap_clear_bit (e1, SSA_NAME_VERSION (n1));
|
|
bitmap_clear_bit (e2, SSA_NAME_VERSION (n2));
|
|
|
|
return (comp == EQ_EXPR || comp == GE_EXPR || comp == LE_EXPR)
|
|
? boolean_true_node
|
|
: boolean_false_node;
|
|
}
|
|
|
|
/* Start at -1. Set it to 0 if we do a comparison without relying
|
|
on overflow, or 1 if all comparisons rely on overflow. */
|
|
used_strict_overflow = -1;
|
|
|
|
/* Otherwise, compare all the equivalent ranges. First, add N1 and
|
|
N2 to their own set of equivalences to avoid duplicating the body
|
|
of the loop just to check N1 and N2 ranges. */
|
|
EXECUTE_IF_SET_IN_BITMAP (e1, 0, i1, bi1)
|
|
{
|
|
value_range_t vr1 = get_vr_for_comparison (i1);
|
|
|
|
t = retval = NULL_TREE;
|
|
EXECUTE_IF_SET_IN_BITMAP (e2, 0, i2, bi2)
|
|
{
|
|
bool sop = false;
|
|
|
|
value_range_t vr2 = get_vr_for_comparison (i2);
|
|
|
|
t = compare_ranges (comp, &vr1, &vr2, &sop);
|
|
if (t)
|
|
{
|
|
/* If we get different answers from different members
|
|
of the equivalence set this check must be in a dead
|
|
code region. Folding it to a trap representation
|
|
would be correct here. For now just return don't-know. */
|
|
if (retval != NULL
|
|
&& t != retval)
|
|
{
|
|
bitmap_clear_bit (e1, SSA_NAME_VERSION (n1));
|
|
bitmap_clear_bit (e2, SSA_NAME_VERSION (n2));
|
|
return NULL_TREE;
|
|
}
|
|
retval = t;
|
|
|
|
if (!sop)
|
|
used_strict_overflow = 0;
|
|
else if (used_strict_overflow < 0)
|
|
used_strict_overflow = 1;
|
|
}
|
|
}
|
|
|
|
if (retval)
|
|
{
|
|
bitmap_clear_bit (e1, SSA_NAME_VERSION (n1));
|
|
bitmap_clear_bit (e2, SSA_NAME_VERSION (n2));
|
|
if (used_strict_overflow > 0)
|
|
*strict_overflow_p = true;
|
|
return retval;
|
|
}
|
|
}
|
|
|
|
/* None of the equivalent ranges are useful in computing this
|
|
comparison. */
|
|
bitmap_clear_bit (e1, SSA_NAME_VERSION (n1));
|
|
bitmap_clear_bit (e2, SSA_NAME_VERSION (n2));
|
|
return NULL_TREE;
|
|
}
|
|
|
|
/* Helper function for vrp_evaluate_conditional_warnv. */
|
|
|
|
static tree
|
|
vrp_evaluate_conditional_warnv_with_ops_using_ranges (enum tree_code code,
|
|
tree op0, tree op1,
|
|
bool * strict_overflow_p)
|
|
{
|
|
value_range_t *vr0, *vr1;
|
|
|
|
vr0 = (TREE_CODE (op0) == SSA_NAME) ? get_value_range (op0) : NULL;
|
|
vr1 = (TREE_CODE (op1) == SSA_NAME) ? get_value_range (op1) : NULL;
|
|
|
|
if (vr0 && vr1)
|
|
return compare_ranges (code, vr0, vr1, strict_overflow_p);
|
|
else if (vr0 && vr1 == NULL)
|
|
return compare_range_with_value (code, vr0, op1, strict_overflow_p);
|
|
else if (vr0 == NULL && vr1)
|
|
return (compare_range_with_value
|
|
(swap_tree_comparison (code), vr1, op0, strict_overflow_p));
|
|
return NULL;
|
|
}
|
|
|
|
/* Helper function for vrp_evaluate_conditional_warnv. */
|
|
|
|
static tree
|
|
vrp_evaluate_conditional_warnv_with_ops (enum tree_code code, tree op0,
|
|
tree op1, bool use_equiv_p,
|
|
bool *strict_overflow_p, bool *only_ranges)
|
|
{
|
|
tree ret;
|
|
if (only_ranges)
|
|
*only_ranges = true;
|
|
|
|
/* We only deal with integral and pointer types. */
|
|
if (!INTEGRAL_TYPE_P (TREE_TYPE (op0))
|
|
&& !POINTER_TYPE_P (TREE_TYPE (op0)))
|
|
return NULL_TREE;
|
|
|
|
if (use_equiv_p)
|
|
{
|
|
if (only_ranges
|
|
&& (ret = vrp_evaluate_conditional_warnv_with_ops_using_ranges
|
|
(code, op0, op1, strict_overflow_p)))
|
|
return ret;
|
|
*only_ranges = false;
|
|
if (TREE_CODE (op0) == SSA_NAME && TREE_CODE (op1) == SSA_NAME)
|
|
return compare_names (code, op0, op1, strict_overflow_p);
|
|
else if (TREE_CODE (op0) == SSA_NAME)
|
|
return compare_name_with_value (code, op0, op1, strict_overflow_p);
|
|
else if (TREE_CODE (op1) == SSA_NAME)
|
|
return (compare_name_with_value
|
|
(swap_tree_comparison (code), op1, op0, strict_overflow_p));
|
|
}
|
|
else
|
|
return vrp_evaluate_conditional_warnv_with_ops_using_ranges (code, op0, op1,
|
|
strict_overflow_p);
|
|
return NULL_TREE;
|
|
}
|
|
|
|
/* Given (CODE OP0 OP1) within STMT, try to simplify it based on value range
|
|
information. Return NULL if the conditional can not be evaluated.
|
|
The ranges of all the names equivalent with the operands in COND
|
|
will be used when trying to compute the value. If the result is
|
|
based on undefined signed overflow, issue a warning if
|
|
appropriate. */
|
|
|
|
static tree
|
|
vrp_evaluate_conditional (enum tree_code code, tree op0, tree op1, gimple stmt)
|
|
{
|
|
bool sop;
|
|
tree ret;
|
|
bool only_ranges;
|
|
|
|
/* Some passes and foldings leak constants with overflow flag set
|
|
into the IL. Avoid doing wrong things with these and bail out. */
|
|
if ((TREE_CODE (op0) == INTEGER_CST
|
|
&& TREE_OVERFLOW (op0))
|
|
|| (TREE_CODE (op1) == INTEGER_CST
|
|
&& TREE_OVERFLOW (op1)))
|
|
return NULL_TREE;
|
|
|
|
sop = false;
|
|
ret = vrp_evaluate_conditional_warnv_with_ops (code, op0, op1, true, &sop,
|
|
&only_ranges);
|
|
|
|
if (ret && sop)
|
|
{
|
|
enum warn_strict_overflow_code wc;
|
|
const char* warnmsg;
|
|
|
|
if (is_gimple_min_invariant (ret))
|
|
{
|
|
wc = WARN_STRICT_OVERFLOW_CONDITIONAL;
|
|
warnmsg = G_("assuming signed overflow does not occur when "
|
|
"simplifying conditional to constant");
|
|
}
|
|
else
|
|
{
|
|
wc = WARN_STRICT_OVERFLOW_COMPARISON;
|
|
warnmsg = G_("assuming signed overflow does not occur when "
|
|
"simplifying conditional");
|
|
}
|
|
|
|
if (issue_strict_overflow_warning (wc))
|
|
{
|
|
location_t location;
|
|
|
|
if (!gimple_has_location (stmt))
|
|
location = input_location;
|
|
else
|
|
location = gimple_location (stmt);
|
|
warning_at (location, OPT_Wstrict_overflow, "%s", warnmsg);
|
|
}
|
|
}
|
|
|
|
if (warn_type_limits
|
|
&& ret && only_ranges
|
|
&& TREE_CODE_CLASS (code) == tcc_comparison
|
|
&& TREE_CODE (op0) == SSA_NAME)
|
|
{
|
|
/* If the comparison is being folded and the operand on the LHS
|
|
is being compared against a constant value that is outside of
|
|
the natural range of OP0's type, then the predicate will
|
|
always fold regardless of the value of OP0. If -Wtype-limits
|
|
was specified, emit a warning. */
|
|
tree type = TREE_TYPE (op0);
|
|
value_range_t *vr0 = get_value_range (op0);
|
|
|
|
if (vr0->type != VR_VARYING
|
|
&& INTEGRAL_TYPE_P (type)
|
|
&& vrp_val_is_min (vr0->min)
|
|
&& vrp_val_is_max (vr0->max)
|
|
&& is_gimple_min_invariant (op1))
|
|
{
|
|
location_t location;
|
|
|
|
if (!gimple_has_location (stmt))
|
|
location = input_location;
|
|
else
|
|
location = gimple_location (stmt);
|
|
|
|
warning_at (location, OPT_Wtype_limits,
|
|
integer_zerop (ret)
|
|
? G_("comparison always false "
|
|
"due to limited range of data type")
|
|
: G_("comparison always true "
|
|
"due to limited range of data type"));
|
|
}
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
|
|
/* Visit conditional statement STMT. If we can determine which edge
|
|
will be taken out of STMT's basic block, record it in
|
|
*TAKEN_EDGE_P and return SSA_PROP_INTERESTING. Otherwise, return
|
|
SSA_PROP_VARYING. */
|
|
|
|
static enum ssa_prop_result
|
|
vrp_visit_cond_stmt (gimple stmt, edge *taken_edge_p)
|
|
{
|
|
tree val;
|
|
bool sop;
|
|
|
|
*taken_edge_p = NULL;
|
|
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
{
|
|
tree use;
|
|
ssa_op_iter i;
|
|
|
|
fprintf (dump_file, "\nVisiting conditional with predicate: ");
|
|
print_gimple_stmt (dump_file, stmt, 0, 0);
|
|
fprintf (dump_file, "\nWith known ranges\n");
|
|
|
|
FOR_EACH_SSA_TREE_OPERAND (use, stmt, i, SSA_OP_USE)
|
|
{
|
|
fprintf (dump_file, "\t");
|
|
print_generic_expr (dump_file, use, 0);
|
|
fprintf (dump_file, ": ");
|
|
dump_value_range (dump_file, vr_value[SSA_NAME_VERSION (use)]);
|
|
}
|
|
|
|
fprintf (dump_file, "\n");
|
|
}
|
|
|
|
/* Compute the value of the predicate COND by checking the known
|
|
ranges of each of its operands.
|
|
|
|
Note that we cannot evaluate all the equivalent ranges here
|
|
because those ranges may not yet be final and with the current
|
|
propagation strategy, we cannot determine when the value ranges
|
|
of the names in the equivalence set have changed.
|
|
|
|
For instance, given the following code fragment
|
|
|
|
i_5 = PHI <8, i_13>
|
|
...
|
|
i_14 = ASSERT_EXPR <i_5, i_5 != 0>
|
|
if (i_14 == 1)
|
|
...
|
|
|
|
Assume that on the first visit to i_14, i_5 has the temporary
|
|
range [8, 8] because the second argument to the PHI function is
|
|
not yet executable. We derive the range ~[0, 0] for i_14 and the
|
|
equivalence set { i_5 }. So, when we visit 'if (i_14 == 1)' for
|
|
the first time, since i_14 is equivalent to the range [8, 8], we
|
|
determine that the predicate is always false.
|
|
|
|
On the next round of propagation, i_13 is determined to be
|
|
VARYING, which causes i_5 to drop down to VARYING. So, another
|
|
visit to i_14 is scheduled. In this second visit, we compute the
|
|
exact same range and equivalence set for i_14, namely ~[0, 0] and
|
|
{ i_5 }. But we did not have the previous range for i_5
|
|
registered, so vrp_visit_assignment thinks that the range for
|
|
i_14 has not changed. Therefore, the predicate 'if (i_14 == 1)'
|
|
is not visited again, which stops propagation from visiting
|
|
statements in the THEN clause of that if().
|
|
|
|
To properly fix this we would need to keep the previous range
|
|
value for the names in the equivalence set. This way we would've
|
|
discovered that from one visit to the other i_5 changed from
|
|
range [8, 8] to VR_VARYING.
|
|
|
|
However, fixing this apparent limitation may not be worth the
|
|
additional checking. Testing on several code bases (GCC, DLV,
|
|
MICO, TRAMP3D and SPEC2000) showed that doing this results in
|
|
4 more predicates folded in SPEC. */
|
|
sop = false;
|
|
|
|
val = vrp_evaluate_conditional_warnv_with_ops (gimple_cond_code (stmt),
|
|
gimple_cond_lhs (stmt),
|
|
gimple_cond_rhs (stmt),
|
|
false, &sop, NULL);
|
|
if (val)
|
|
{
|
|
if (!sop)
|
|
*taken_edge_p = find_taken_edge (gimple_bb (stmt), val);
|
|
else
|
|
{
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
fprintf (dump_file,
|
|
"\nIgnoring predicate evaluation because "
|
|
"it assumes that signed overflow is undefined");
|
|
val = NULL_TREE;
|
|
}
|
|
}
|
|
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
{
|
|
fprintf (dump_file, "\nPredicate evaluates to: ");
|
|
if (val == NULL_TREE)
|
|
fprintf (dump_file, "DON'T KNOW\n");
|
|
else
|
|
print_generic_stmt (dump_file, val, 0);
|
|
}
|
|
|
|
return (*taken_edge_p) ? SSA_PROP_INTERESTING : SSA_PROP_VARYING;
|
|
}
|
|
|
|
/* Searches the case label vector VEC for the index *IDX of the CASE_LABEL
|
|
that includes the value VAL. The search is restricted to the range
|
|
[START_IDX, n - 1] where n is the size of VEC.
|
|
|
|
If there is a CASE_LABEL for VAL, its index is placed in IDX and true is
|
|
returned.
|
|
|
|
If there is no CASE_LABEL for VAL and there is one that is larger than VAL,
|
|
it is placed in IDX and false is returned.
|
|
|
|
If VAL is larger than any CASE_LABEL, n is placed on IDX and false is
|
|
returned. */
|
|
|
|
static bool
|
|
find_case_label_index (gimple stmt, size_t start_idx, tree val, size_t *idx)
|
|
{
|
|
size_t n = gimple_switch_num_labels (stmt);
|
|
size_t low, high;
|
|
|
|
/* Find case label for minimum of the value range or the next one.
|
|
At each iteration we are searching in [low, high - 1]. */
|
|
|
|
for (low = start_idx, high = n; high != low; )
|
|
{
|
|
tree t;
|
|
int cmp;
|
|
/* Note that i != high, so we never ask for n. */
|
|
size_t i = (high + low) / 2;
|
|
t = gimple_switch_label (stmt, i);
|
|
|
|
/* Cache the result of comparing CASE_LOW and val. */
|
|
cmp = tree_int_cst_compare (CASE_LOW (t), val);
|
|
|
|
if (cmp == 0)
|
|
{
|
|
/* Ranges cannot be empty. */
|
|
*idx = i;
|
|
return true;
|
|
}
|
|
else if (cmp > 0)
|
|
high = i;
|
|
else
|
|
{
|
|
low = i + 1;
|
|
if (CASE_HIGH (t) != NULL
|
|
&& tree_int_cst_compare (CASE_HIGH (t), val) >= 0)
|
|
{
|
|
*idx = i;
|
|
return true;
|
|
}
|
|
}
|
|
}
|
|
|
|
*idx = high;
|
|
return false;
|
|
}
|
|
|
|
/* Searches the case label vector VEC for the range of CASE_LABELs that is used
|
|
for values between MIN and MAX. The first index is placed in MIN_IDX. The
|
|
last index is placed in MAX_IDX. If the range of CASE_LABELs is empty
|
|
then MAX_IDX < MIN_IDX.
|
|
Returns true if the default label is not needed. */
|
|
|
|
static bool
|
|
find_case_label_range (gimple stmt, tree min, tree max, size_t *min_idx,
|
|
size_t *max_idx)
|
|
{
|
|
size_t i, j;
|
|
bool min_take_default = !find_case_label_index (stmt, 1, min, &i);
|
|
bool max_take_default = !find_case_label_index (stmt, i, max, &j);
|
|
|
|
if (i == j
|
|
&& min_take_default
|
|
&& max_take_default)
|
|
{
|
|
/* Only the default case label reached.
|
|
Return an empty range. */
|
|
*min_idx = 1;
|
|
*max_idx = 0;
|
|
return false;
|
|
}
|
|
else
|
|
{
|
|
bool take_default = min_take_default || max_take_default;
|
|
tree low, high;
|
|
size_t k;
|
|
|
|
if (max_take_default)
|
|
j--;
|
|
|
|
/* If the case label range is continuous, we do not need
|
|
the default case label. Verify that. */
|
|
high = CASE_LOW (gimple_switch_label (stmt, i));
|
|
if (CASE_HIGH (gimple_switch_label (stmt, i)))
|
|
high = CASE_HIGH (gimple_switch_label (stmt, i));
|
|
for (k = i + 1; k <= j; ++k)
|
|
{
|
|
low = CASE_LOW (gimple_switch_label (stmt, k));
|
|
if (!integer_onep (int_const_binop (MINUS_EXPR, low, high)))
|
|
{
|
|
take_default = true;
|
|
break;
|
|
}
|
|
high = low;
|
|
if (CASE_HIGH (gimple_switch_label (stmt, k)))
|
|
high = CASE_HIGH (gimple_switch_label (stmt, k));
|
|
}
|
|
|
|
*min_idx = i;
|
|
*max_idx = j;
|
|
return !take_default;
|
|
}
|
|
}
|
|
|
|
/* Searches the case label vector VEC for the ranges of CASE_LABELs that are
|
|
used in range VR. The indices are placed in MIN_IDX1, MAX_IDX, MIN_IDX2 and
|
|
MAX_IDX2. If the ranges of CASE_LABELs are empty then MAX_IDX1 < MIN_IDX1.
|
|
Returns true if the default label is not needed. */
|
|
|
|
static bool
|
|
find_case_label_ranges (gimple stmt, value_range_t *vr, size_t *min_idx1,
|
|
size_t *max_idx1, size_t *min_idx2,
|
|
size_t *max_idx2)
|
|
{
|
|
size_t i, j, k, l;
|
|
unsigned int n = gimple_switch_num_labels (stmt);
|
|
bool take_default;
|
|
tree case_low, case_high;
|
|
tree min = vr->min, max = vr->max;
|
|
|
|
gcc_checking_assert (vr->type == VR_RANGE || vr->type == VR_ANTI_RANGE);
|
|
|
|
take_default = !find_case_label_range (stmt, min, max, &i, &j);
|
|
|
|
/* Set second range to emtpy. */
|
|
*min_idx2 = 1;
|
|
*max_idx2 = 0;
|
|
|
|
if (vr->type == VR_RANGE)
|
|
{
|
|
*min_idx1 = i;
|
|
*max_idx1 = j;
|
|
return !take_default;
|
|
}
|
|
|
|
/* Set first range to all case labels. */
|
|
*min_idx1 = 1;
|
|
*max_idx1 = n - 1;
|
|
|
|
if (i > j)
|
|
return false;
|
|
|
|
/* Make sure all the values of case labels [i , j] are contained in
|
|
range [MIN, MAX]. */
|
|
case_low = CASE_LOW (gimple_switch_label (stmt, i));
|
|
case_high = CASE_HIGH (gimple_switch_label (stmt, j));
|
|
if (tree_int_cst_compare (case_low, min) < 0)
|
|
i += 1;
|
|
if (case_high != NULL_TREE
|
|
&& tree_int_cst_compare (max, case_high) < 0)
|
|
j -= 1;
|
|
|
|
if (i > j)
|
|
return false;
|
|
|
|
/* If the range spans case labels [i, j], the corresponding anti-range spans
|
|
the labels [1, i - 1] and [j + 1, n - 1]. */
|
|
k = j + 1;
|
|
l = n - 1;
|
|
if (k > l)
|
|
{
|
|
k = 1;
|
|
l = 0;
|
|
}
|
|
|
|
j = i - 1;
|
|
i = 1;
|
|
if (i > j)
|
|
{
|
|
i = k;
|
|
j = l;
|
|
k = 1;
|
|
l = 0;
|
|
}
|
|
|
|
*min_idx1 = i;
|
|
*max_idx1 = j;
|
|
*min_idx2 = k;
|
|
*max_idx2 = l;
|
|
return false;
|
|
}
|
|
|
|
/* Visit switch statement STMT. If we can determine which edge
|
|
will be taken out of STMT's basic block, record it in
|
|
*TAKEN_EDGE_P and return SSA_PROP_INTERESTING. Otherwise, return
|
|
SSA_PROP_VARYING. */
|
|
|
|
static enum ssa_prop_result
|
|
vrp_visit_switch_stmt (gimple stmt, edge *taken_edge_p)
|
|
{
|
|
tree op, val;
|
|
value_range_t *vr;
|
|
size_t i = 0, j = 0, k, l;
|
|
bool take_default;
|
|
|
|
*taken_edge_p = NULL;
|
|
op = gimple_switch_index (stmt);
|
|
if (TREE_CODE (op) != SSA_NAME)
|
|
return SSA_PROP_VARYING;
|
|
|
|
vr = get_value_range (op);
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
{
|
|
fprintf (dump_file, "\nVisiting switch expression with operand ");
|
|
print_generic_expr (dump_file, op, 0);
|
|
fprintf (dump_file, " with known range ");
|
|
dump_value_range (dump_file, vr);
|
|
fprintf (dump_file, "\n");
|
|
}
|
|
|
|
if ((vr->type != VR_RANGE
|
|
&& vr->type != VR_ANTI_RANGE)
|
|
|| symbolic_range_p (vr))
|
|
return SSA_PROP_VARYING;
|
|
|
|
/* Find the single edge that is taken from the switch expression. */
|
|
take_default = !find_case_label_ranges (stmt, vr, &i, &j, &k, &l);
|
|
|
|
/* Check if the range spans no CASE_LABEL. If so, we only reach the default
|
|
label */
|
|
if (j < i)
|
|
{
|
|
gcc_assert (take_default);
|
|
val = gimple_switch_default_label (stmt);
|
|
}
|
|
else
|
|
{
|
|
/* Check if labels with index i to j and maybe the default label
|
|
are all reaching the same label. */
|
|
|
|
val = gimple_switch_label (stmt, i);
|
|
if (take_default
|
|
&& CASE_LABEL (gimple_switch_default_label (stmt))
|
|
!= CASE_LABEL (val))
|
|
{
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
fprintf (dump_file, " not a single destination for this "
|
|
"range\n");
|
|
return SSA_PROP_VARYING;
|
|
}
|
|
for (++i; i <= j; ++i)
|
|
{
|
|
if (CASE_LABEL (gimple_switch_label (stmt, i)) != CASE_LABEL (val))
|
|
{
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
fprintf (dump_file, " not a single destination for this "
|
|
"range\n");
|
|
return SSA_PROP_VARYING;
|
|
}
|
|
}
|
|
for (; k <= l; ++k)
|
|
{
|
|
if (CASE_LABEL (gimple_switch_label (stmt, k)) != CASE_LABEL (val))
|
|
{
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
fprintf (dump_file, " not a single destination for this "
|
|
"range\n");
|
|
return SSA_PROP_VARYING;
|
|
}
|
|
}
|
|
}
|
|
|
|
*taken_edge_p = find_edge (gimple_bb (stmt),
|
|
label_to_block (CASE_LABEL (val)));
|
|
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
{
|
|
fprintf (dump_file, " will take edge to ");
|
|
print_generic_stmt (dump_file, CASE_LABEL (val), 0);
|
|
}
|
|
|
|
return SSA_PROP_INTERESTING;
|
|
}
|
|
|
|
|
|
/* Evaluate statement STMT. If the statement produces a useful range,
|
|
return SSA_PROP_INTERESTING and record the SSA name with the
|
|
interesting range into *OUTPUT_P.
|
|
|
|
If STMT is a conditional branch and we can determine its truth
|
|
value, the taken edge is recorded in *TAKEN_EDGE_P.
|
|
|
|
If STMT produces a varying value, return SSA_PROP_VARYING. */
|
|
|
|
static enum ssa_prop_result
|
|
vrp_visit_stmt (gimple stmt, edge *taken_edge_p, tree *output_p)
|
|
{
|
|
tree def;
|
|
ssa_op_iter iter;
|
|
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
{
|
|
fprintf (dump_file, "\nVisiting statement:\n");
|
|
print_gimple_stmt (dump_file, stmt, 0, dump_flags);
|
|
fprintf (dump_file, "\n");
|
|
}
|
|
|
|
if (!stmt_interesting_for_vrp (stmt))
|
|
gcc_assert (stmt_ends_bb_p (stmt));
|
|
else if (is_gimple_assign (stmt) || is_gimple_call (stmt))
|
|
{
|
|
/* In general, assignments with virtual operands are not useful
|
|
for deriving ranges, with the obvious exception of calls to
|
|
builtin functions. */
|
|
if ((is_gimple_call (stmt)
|
|
&& gimple_call_fndecl (stmt) != NULL_TREE
|
|
&& DECL_BUILT_IN (gimple_call_fndecl (stmt)))
|
|
|| !gimple_vuse (stmt))
|
|
return vrp_visit_assignment_or_call (stmt, output_p);
|
|
}
|
|
else if (gimple_code (stmt) == GIMPLE_COND)
|
|
return vrp_visit_cond_stmt (stmt, taken_edge_p);
|
|
else if (gimple_code (stmt) == GIMPLE_SWITCH)
|
|
return vrp_visit_switch_stmt (stmt, taken_edge_p);
|
|
|
|
/* All other statements produce nothing of interest for VRP, so mark
|
|
their outputs varying and prevent further simulation. */
|
|
FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_DEF)
|
|
set_value_range_to_varying (get_value_range (def));
|
|
|
|
return SSA_PROP_VARYING;
|
|
}
|
|
|
|
/* Union the two value-ranges { *VR0TYPE, *VR0MIN, *VR0MAX } and
|
|
{ VR1TYPE, VR0MIN, VR0MAX } and store the result
|
|
in { *VR0TYPE, *VR0MIN, *VR0MAX }. This may not be the smallest
|
|
possible such range. The resulting range is not canonicalized. */
|
|
|
|
static void
|
|
union_ranges (enum value_range_type *vr0type,
|
|
tree *vr0min, tree *vr0max,
|
|
enum value_range_type vr1type,
|
|
tree vr1min, tree vr1max)
|
|
{
|
|
bool mineq = operand_equal_p (*vr0min, vr1min, 0);
|
|
bool maxeq = operand_equal_p (*vr0max, vr1max, 0);
|
|
|
|
/* [] is vr0, () is vr1 in the following classification comments. */
|
|
if (mineq && maxeq)
|
|
{
|
|
/* [( )] */
|
|
if (*vr0type == vr1type)
|
|
/* Nothing to do for equal ranges. */
|
|
;
|
|
else if ((*vr0type == VR_RANGE
|
|
&& vr1type == VR_ANTI_RANGE)
|
|
|| (*vr0type == VR_ANTI_RANGE
|
|
&& vr1type == VR_RANGE))
|
|
{
|
|
/* For anti-range with range union the result is varying. */
|
|
goto give_up;
|
|
}
|
|
else
|
|
gcc_unreachable ();
|
|
}
|
|
else if (operand_less_p (*vr0max, vr1min) == 1
|
|
|| operand_less_p (vr1max, *vr0min) == 1)
|
|
{
|
|
/* [ ] ( ) or ( ) [ ]
|
|
If the ranges have an empty intersection, result of the union
|
|
operation is the anti-range or if both are anti-ranges
|
|
it covers all. */
|
|
if (*vr0type == VR_ANTI_RANGE
|
|
&& vr1type == VR_ANTI_RANGE)
|
|
goto give_up;
|
|
else if (*vr0type == VR_ANTI_RANGE
|
|
&& vr1type == VR_RANGE)
|
|
;
|
|
else if (*vr0type == VR_RANGE
|
|
&& vr1type == VR_ANTI_RANGE)
|
|
{
|
|
*vr0type = vr1type;
|
|
*vr0min = vr1min;
|
|
*vr0max = vr1max;
|
|
}
|
|
else if (*vr0type == VR_RANGE
|
|
&& vr1type == VR_RANGE)
|
|
{
|
|
/* The result is the convex hull of both ranges. */
|
|
if (operand_less_p (*vr0max, vr1min) == 1)
|
|
{
|
|
/* If the result can be an anti-range, create one. */
|
|
if (TREE_CODE (*vr0max) == INTEGER_CST
|
|
&& TREE_CODE (vr1min) == INTEGER_CST
|
|
&& vrp_val_is_min (*vr0min)
|
|
&& vrp_val_is_max (vr1max))
|
|
{
|
|
tree min = int_const_binop (PLUS_EXPR,
|
|
*vr0max, integer_one_node);
|
|
tree max = int_const_binop (MINUS_EXPR,
|
|
vr1min, integer_one_node);
|
|
if (!operand_less_p (max, min))
|
|
{
|
|
*vr0type = VR_ANTI_RANGE;
|
|
*vr0min = min;
|
|
*vr0max = max;
|
|
}
|
|
else
|
|
*vr0max = vr1max;
|
|
}
|
|
else
|
|
*vr0max = vr1max;
|
|
}
|
|
else
|
|
{
|
|
/* If the result can be an anti-range, create one. */
|
|
if (TREE_CODE (vr1max) == INTEGER_CST
|
|
&& TREE_CODE (*vr0min) == INTEGER_CST
|
|
&& vrp_val_is_min (vr1min)
|
|
&& vrp_val_is_max (*vr0max))
|
|
{
|
|
tree min = int_const_binop (PLUS_EXPR,
|
|
vr1max, integer_one_node);
|
|
tree max = int_const_binop (MINUS_EXPR,
|
|
*vr0min, integer_one_node);
|
|
if (!operand_less_p (max, min))
|
|
{
|
|
*vr0type = VR_ANTI_RANGE;
|
|
*vr0min = min;
|
|
*vr0max = max;
|
|
}
|
|
else
|
|
*vr0min = vr1min;
|
|
}
|
|
else
|
|
*vr0min = vr1min;
|
|
}
|
|
}
|
|
else
|
|
gcc_unreachable ();
|
|
}
|
|
else if ((maxeq || operand_less_p (vr1max, *vr0max) == 1)
|
|
&& (mineq || operand_less_p (*vr0min, vr1min) == 1))
|
|
{
|
|
/* [ ( ) ] or [( ) ] or [ ( )] */
|
|
if (*vr0type == VR_RANGE
|
|
&& vr1type == VR_RANGE)
|
|
;
|
|
else if (*vr0type == VR_ANTI_RANGE
|
|
&& vr1type == VR_ANTI_RANGE)
|
|
{
|
|
*vr0type = vr1type;
|
|
*vr0min = vr1min;
|
|
*vr0max = vr1max;
|
|
}
|
|
else if (*vr0type == VR_ANTI_RANGE
|
|
&& vr1type == VR_RANGE)
|
|
{
|
|
/* Arbitrarily choose the right or left gap. */
|
|
if (!mineq && TREE_CODE (vr1min) == INTEGER_CST)
|
|
*vr0max = int_const_binop (MINUS_EXPR, vr1min, integer_one_node);
|
|
else if (!maxeq && TREE_CODE (vr1max) == INTEGER_CST)
|
|
*vr0min = int_const_binop (PLUS_EXPR, vr1max, integer_one_node);
|
|
else
|
|
goto give_up;
|
|
}
|
|
else if (*vr0type == VR_RANGE
|
|
&& vr1type == VR_ANTI_RANGE)
|
|
/* The result covers everything. */
|
|
goto give_up;
|
|
else
|
|
gcc_unreachable ();
|
|
}
|
|
else if ((maxeq || operand_less_p (*vr0max, vr1max) == 1)
|
|
&& (mineq || operand_less_p (vr1min, *vr0min) == 1))
|
|
{
|
|
/* ( [ ] ) or ([ ] ) or ( [ ]) */
|
|
if (*vr0type == VR_RANGE
|
|
&& vr1type == VR_RANGE)
|
|
{
|
|
*vr0type = vr1type;
|
|
*vr0min = vr1min;
|
|
*vr0max = vr1max;
|
|
}
|
|
else if (*vr0type == VR_ANTI_RANGE
|
|
&& vr1type == VR_ANTI_RANGE)
|
|
;
|
|
else if (*vr0type == VR_RANGE
|
|
&& vr1type == VR_ANTI_RANGE)
|
|
{
|
|
*vr0type = VR_ANTI_RANGE;
|
|
if (!mineq && TREE_CODE (*vr0min) == INTEGER_CST)
|
|
{
|
|
*vr0max = int_const_binop (MINUS_EXPR, *vr0min, integer_one_node);
|
|
*vr0min = vr1min;
|
|
}
|
|
else if (!maxeq && TREE_CODE (*vr0max) == INTEGER_CST)
|
|
{
|
|
*vr0min = int_const_binop (PLUS_EXPR, *vr0max, integer_one_node);
|
|
*vr0max = vr1max;
|
|
}
|
|
else
|
|
goto give_up;
|
|
}
|
|
else if (*vr0type == VR_ANTI_RANGE
|
|
&& vr1type == VR_RANGE)
|
|
/* The result covers everything. */
|
|
goto give_up;
|
|
else
|
|
gcc_unreachable ();
|
|
}
|
|
else if ((operand_less_p (vr1min, *vr0max) == 1
|
|
|| operand_equal_p (vr1min, *vr0max, 0))
|
|
&& operand_less_p (*vr0min, vr1min) == 1)
|
|
{
|
|
/* [ ( ] ) or [ ]( ) */
|
|
if (*vr0type == VR_RANGE
|
|
&& vr1type == VR_RANGE)
|
|
*vr0max = vr1max;
|
|
else if (*vr0type == VR_ANTI_RANGE
|
|
&& vr1type == VR_ANTI_RANGE)
|
|
*vr0min = vr1min;
|
|
else if (*vr0type == VR_ANTI_RANGE
|
|
&& vr1type == VR_RANGE)
|
|
{
|
|
if (TREE_CODE (vr1min) == INTEGER_CST)
|
|
*vr0max = int_const_binop (MINUS_EXPR, vr1min, integer_one_node);
|
|
else
|
|
goto give_up;
|
|
}
|
|
else if (*vr0type == VR_RANGE
|
|
&& vr1type == VR_ANTI_RANGE)
|
|
{
|
|
if (TREE_CODE (*vr0max) == INTEGER_CST)
|
|
{
|
|
*vr0type = vr1type;
|
|
*vr0min = int_const_binop (PLUS_EXPR, *vr0max, integer_one_node);
|
|
*vr0max = vr1max;
|
|
}
|
|
else
|
|
goto give_up;
|
|
}
|
|
else
|
|
gcc_unreachable ();
|
|
}
|
|
else if ((operand_less_p (*vr0min, vr1max) == 1
|
|
|| operand_equal_p (*vr0min, vr1max, 0))
|
|
&& operand_less_p (vr1min, *vr0min) == 1)
|
|
{
|
|
/* ( [ ) ] or ( )[ ] */
|
|
if (*vr0type == VR_RANGE
|
|
&& vr1type == VR_RANGE)
|
|
*vr0min = vr1min;
|
|
else if (*vr0type == VR_ANTI_RANGE
|
|
&& vr1type == VR_ANTI_RANGE)
|
|
*vr0max = vr1max;
|
|
else if (*vr0type == VR_ANTI_RANGE
|
|
&& vr1type == VR_RANGE)
|
|
{
|
|
if (TREE_CODE (vr1max) == INTEGER_CST)
|
|
*vr0min = int_const_binop (PLUS_EXPR, vr1max, integer_one_node);
|
|
else
|
|
goto give_up;
|
|
}
|
|
else if (*vr0type == VR_RANGE
|
|
&& vr1type == VR_ANTI_RANGE)
|
|
{
|
|
if (TREE_CODE (*vr0min) == INTEGER_CST)
|
|
{
|
|
*vr0type = vr1type;
|
|
*vr0min = vr1min;
|
|
*vr0max = int_const_binop (MINUS_EXPR, *vr0min, integer_one_node);
|
|
}
|
|
else
|
|
goto give_up;
|
|
}
|
|
else
|
|
gcc_unreachable ();
|
|
}
|
|
else
|
|
goto give_up;
|
|
|
|
return;
|
|
|
|
give_up:
|
|
*vr0type = VR_VARYING;
|
|
*vr0min = NULL_TREE;
|
|
*vr0max = NULL_TREE;
|
|
}
|
|
|
|
/* Intersect the two value-ranges { *VR0TYPE, *VR0MIN, *VR0MAX } and
|
|
{ VR1TYPE, VR0MIN, VR0MAX } and store the result
|
|
in { *VR0TYPE, *VR0MIN, *VR0MAX }. This may not be the smallest
|
|
possible such range. The resulting range is not canonicalized. */
|
|
|
|
static void
|
|
intersect_ranges (enum value_range_type *vr0type,
|
|
tree *vr0min, tree *vr0max,
|
|
enum value_range_type vr1type,
|
|
tree vr1min, tree vr1max)
|
|
{
|
|
bool mineq = operand_equal_p (*vr0min, vr1min, 0);
|
|
bool maxeq = operand_equal_p (*vr0max, vr1max, 0);
|
|
|
|
/* [] is vr0, () is vr1 in the following classification comments. */
|
|
if (mineq && maxeq)
|
|
{
|
|
/* [( )] */
|
|
if (*vr0type == vr1type)
|
|
/* Nothing to do for equal ranges. */
|
|
;
|
|
else if ((*vr0type == VR_RANGE
|
|
&& vr1type == VR_ANTI_RANGE)
|
|
|| (*vr0type == VR_ANTI_RANGE
|
|
&& vr1type == VR_RANGE))
|
|
{
|
|
/* For anti-range with range intersection the result is empty. */
|
|
*vr0type = VR_UNDEFINED;
|
|
*vr0min = NULL_TREE;
|
|
*vr0max = NULL_TREE;
|
|
}
|
|
else
|
|
gcc_unreachable ();
|
|
}
|
|
else if (operand_less_p (*vr0max, vr1min) == 1
|
|
|| operand_less_p (vr1max, *vr0min) == 1)
|
|
{
|
|
/* [ ] ( ) or ( ) [ ]
|
|
If the ranges have an empty intersection, the result of the
|
|
intersect operation is the range for intersecting an
|
|
anti-range with a range or empty when intersecting two ranges. */
|
|
if (*vr0type == VR_RANGE
|
|
&& vr1type == VR_ANTI_RANGE)
|
|
;
|
|
else if (*vr0type == VR_ANTI_RANGE
|
|
&& vr1type == VR_RANGE)
|
|
{
|
|
*vr0type = vr1type;
|
|
*vr0min = vr1min;
|
|
*vr0max = vr1max;
|
|
}
|
|
else if (*vr0type == VR_RANGE
|
|
&& vr1type == VR_RANGE)
|
|
{
|
|
*vr0type = VR_UNDEFINED;
|
|
*vr0min = NULL_TREE;
|
|
*vr0max = NULL_TREE;
|
|
}
|
|
else if (*vr0type == VR_ANTI_RANGE
|
|
&& vr1type == VR_ANTI_RANGE)
|
|
{
|
|
/* If the anti-ranges are adjacent to each other merge them. */
|
|
if (TREE_CODE (*vr0max) == INTEGER_CST
|
|
&& TREE_CODE (vr1min) == INTEGER_CST
|
|
&& operand_less_p (*vr0max, vr1min) == 1
|
|
&& integer_onep (int_const_binop (MINUS_EXPR,
|
|
vr1min, *vr0max)))
|
|
*vr0max = vr1max;
|
|
else if (TREE_CODE (vr1max) == INTEGER_CST
|
|
&& TREE_CODE (*vr0min) == INTEGER_CST
|
|
&& operand_less_p (vr1max, *vr0min) == 1
|
|
&& integer_onep (int_const_binop (MINUS_EXPR,
|
|
*vr0min, vr1max)))
|
|
*vr0min = vr1min;
|
|
/* Else arbitrarily take VR0. */
|
|
}
|
|
}
|
|
else if ((maxeq || operand_less_p (vr1max, *vr0max) == 1)
|
|
&& (mineq || operand_less_p (*vr0min, vr1min) == 1))
|
|
{
|
|
/* [ ( ) ] or [( ) ] or [ ( )] */
|
|
if (*vr0type == VR_RANGE
|
|
&& vr1type == VR_RANGE)
|
|
{
|
|
/* If both are ranges the result is the inner one. */
|
|
*vr0type = vr1type;
|
|
*vr0min = vr1min;
|
|
*vr0max = vr1max;
|
|
}
|
|
else if (*vr0type == VR_RANGE
|
|
&& vr1type == VR_ANTI_RANGE)
|
|
{
|
|
/* Choose the right gap if the left one is empty. */
|
|
if (mineq)
|
|
{
|
|
if (TREE_CODE (vr1max) == INTEGER_CST)
|
|
*vr0min = int_const_binop (PLUS_EXPR, vr1max, integer_one_node);
|
|
else
|
|
*vr0min = vr1max;
|
|
}
|
|
/* Choose the left gap if the right one is empty. */
|
|
else if (maxeq)
|
|
{
|
|
if (TREE_CODE (vr1min) == INTEGER_CST)
|
|
*vr0max = int_const_binop (MINUS_EXPR, vr1min,
|
|
integer_one_node);
|
|
else
|
|
*vr0max = vr1min;
|
|
}
|
|
/* Choose the anti-range if the range is effectively varying. */
|
|
else if (vrp_val_is_min (*vr0min)
|
|
&& vrp_val_is_max (*vr0max))
|
|
{
|
|
*vr0type = vr1type;
|
|
*vr0min = vr1min;
|
|
*vr0max = vr1max;
|
|
}
|
|
/* Else choose the range. */
|
|
}
|
|
else if (*vr0type == VR_ANTI_RANGE
|
|
&& vr1type == VR_ANTI_RANGE)
|
|
/* If both are anti-ranges the result is the outer one. */
|
|
;
|
|
else if (*vr0type == VR_ANTI_RANGE
|
|
&& vr1type == VR_RANGE)
|
|
{
|
|
/* The intersection is empty. */
|
|
*vr0type = VR_UNDEFINED;
|
|
*vr0min = NULL_TREE;
|
|
*vr0max = NULL_TREE;
|
|
}
|
|
else
|
|
gcc_unreachable ();
|
|
}
|
|
else if ((maxeq || operand_less_p (*vr0max, vr1max) == 1)
|
|
&& (mineq || operand_less_p (vr1min, *vr0min) == 1))
|
|
{
|
|
/* ( [ ] ) or ([ ] ) or ( [ ]) */
|
|
if (*vr0type == VR_RANGE
|
|
&& vr1type == VR_RANGE)
|
|
/* Choose the inner range. */
|
|
;
|
|
else if (*vr0type == VR_ANTI_RANGE
|
|
&& vr1type == VR_RANGE)
|
|
{
|
|
/* Choose the right gap if the left is empty. */
|
|
if (mineq)
|
|
{
|
|
*vr0type = VR_RANGE;
|
|
if (TREE_CODE (*vr0max) == INTEGER_CST)
|
|
*vr0min = int_const_binop (PLUS_EXPR, *vr0max,
|
|
integer_one_node);
|
|
else
|
|
*vr0min = *vr0max;
|
|
*vr0max = vr1max;
|
|
}
|
|
/* Choose the left gap if the right is empty. */
|
|
else if (maxeq)
|
|
{
|
|
*vr0type = VR_RANGE;
|
|
if (TREE_CODE (*vr0min) == INTEGER_CST)
|
|
*vr0max = int_const_binop (MINUS_EXPR, *vr0min,
|
|
integer_one_node);
|
|
else
|
|
*vr0max = *vr0min;
|
|
*vr0min = vr1min;
|
|
}
|
|
/* Choose the anti-range if the range is effectively varying. */
|
|
else if (vrp_val_is_min (vr1min)
|
|
&& vrp_val_is_max (vr1max))
|
|
;
|
|
/* Else choose the range. */
|
|
else
|
|
{
|
|
*vr0type = vr1type;
|
|
*vr0min = vr1min;
|
|
*vr0max = vr1max;
|
|
}
|
|
}
|
|
else if (*vr0type == VR_ANTI_RANGE
|
|
&& vr1type == VR_ANTI_RANGE)
|
|
{
|
|
/* If both are anti-ranges the result is the outer one. */
|
|
*vr0type = vr1type;
|
|
*vr0min = vr1min;
|
|
*vr0max = vr1max;
|
|
}
|
|
else if (vr1type == VR_ANTI_RANGE
|
|
&& *vr0type == VR_RANGE)
|
|
{
|
|
/* The intersection is empty. */
|
|
*vr0type = VR_UNDEFINED;
|
|
*vr0min = NULL_TREE;
|
|
*vr0max = NULL_TREE;
|
|
}
|
|
else
|
|
gcc_unreachable ();
|
|
}
|
|
else if ((operand_less_p (vr1min, *vr0max) == 1
|
|
|| operand_equal_p (vr1min, *vr0max, 0))
|
|
&& operand_less_p (*vr0min, vr1min) == 1)
|
|
{
|
|
/* [ ( ] ) or [ ]( ) */
|
|
if (*vr0type == VR_ANTI_RANGE
|
|
&& vr1type == VR_ANTI_RANGE)
|
|
*vr0max = vr1max;
|
|
else if (*vr0type == VR_RANGE
|
|
&& vr1type == VR_RANGE)
|
|
*vr0min = vr1min;
|
|
else if (*vr0type == VR_RANGE
|
|
&& vr1type == VR_ANTI_RANGE)
|
|
{
|
|
if (TREE_CODE (vr1min) == INTEGER_CST)
|
|
*vr0max = int_const_binop (MINUS_EXPR, vr1min,
|
|
integer_one_node);
|
|
else
|
|
*vr0max = vr1min;
|
|
}
|
|
else if (*vr0type == VR_ANTI_RANGE
|
|
&& vr1type == VR_RANGE)
|
|
{
|
|
*vr0type = VR_RANGE;
|
|
if (TREE_CODE (*vr0max) == INTEGER_CST)
|
|
*vr0min = int_const_binop (PLUS_EXPR, *vr0max,
|
|
integer_one_node);
|
|
else
|
|
*vr0min = *vr0max;
|
|
*vr0max = vr1max;
|
|
}
|
|
else
|
|
gcc_unreachable ();
|
|
}
|
|
else if ((operand_less_p (*vr0min, vr1max) == 1
|
|
|| operand_equal_p (*vr0min, vr1max, 0))
|
|
&& operand_less_p (vr1min, *vr0min) == 1)
|
|
{
|
|
/* ( [ ) ] or ( )[ ] */
|
|
if (*vr0type == VR_ANTI_RANGE
|
|
&& vr1type == VR_ANTI_RANGE)
|
|
*vr0min = vr1min;
|
|
else if (*vr0type == VR_RANGE
|
|
&& vr1type == VR_RANGE)
|
|
*vr0max = vr1max;
|
|
else if (*vr0type == VR_RANGE
|
|
&& vr1type == VR_ANTI_RANGE)
|
|
{
|
|
if (TREE_CODE (vr1max) == INTEGER_CST)
|
|
*vr0min = int_const_binop (PLUS_EXPR, vr1max,
|
|
integer_one_node);
|
|
else
|
|
*vr0min = vr1max;
|
|
}
|
|
else if (*vr0type == VR_ANTI_RANGE
|
|
&& vr1type == VR_RANGE)
|
|
{
|
|
*vr0type = VR_RANGE;
|
|
if (TREE_CODE (*vr0min) == INTEGER_CST)
|
|
*vr0max = int_const_binop (MINUS_EXPR, *vr0min,
|
|
integer_one_node);
|
|
else
|
|
*vr0max = *vr0min;
|
|
*vr0min = vr1min;
|
|
}
|
|
else
|
|
gcc_unreachable ();
|
|
}
|
|
|
|
/* As a fallback simply use { *VRTYPE, *VR0MIN, *VR0MAX } as
|
|
result for the intersection. That's always a conservative
|
|
correct estimate. */
|
|
|
|
return;
|
|
}
|
|
|
|
|
|
/* Intersect the two value-ranges *VR0 and *VR1 and store the result
|
|
in *VR0. This may not be the smallest possible such range. */
|
|
|
|
static void
|
|
vrp_intersect_ranges_1 (value_range_t *vr0, value_range_t *vr1)
|
|
{
|
|
value_range_t saved;
|
|
|
|
/* If either range is VR_VARYING the other one wins. */
|
|
if (vr1->type == VR_VARYING)
|
|
return;
|
|
if (vr0->type == VR_VARYING)
|
|
{
|
|
copy_value_range (vr0, vr1);
|
|
return;
|
|
}
|
|
|
|
/* When either range is VR_UNDEFINED the resulting range is
|
|
VR_UNDEFINED, too. */
|
|
if (vr0->type == VR_UNDEFINED)
|
|
return;
|
|
if (vr1->type == VR_UNDEFINED)
|
|
{
|
|
set_value_range_to_undefined (vr0);
|
|
return;
|
|
}
|
|
|
|
/* Save the original vr0 so we can return it as conservative intersection
|
|
result when our worker turns things to varying. */
|
|
saved = *vr0;
|
|
intersect_ranges (&vr0->type, &vr0->min, &vr0->max,
|
|
vr1->type, vr1->min, vr1->max);
|
|
/* Make sure to canonicalize the result though as the inversion of a
|
|
VR_RANGE can still be a VR_RANGE. */
|
|
set_and_canonicalize_value_range (vr0, vr0->type,
|
|
vr0->min, vr0->max, vr0->equiv);
|
|
/* If that failed, use the saved original VR0. */
|
|
if (vr0->type == VR_VARYING)
|
|
{
|
|
*vr0 = saved;
|
|
return;
|
|
}
|
|
/* If the result is VR_UNDEFINED there is no need to mess with
|
|
the equivalencies. */
|
|
if (vr0->type == VR_UNDEFINED)
|
|
return;
|
|
|
|
/* The resulting set of equivalences for range intersection is the union of
|
|
the two sets. */
|
|
if (vr0->equiv && vr1->equiv && vr0->equiv != vr1->equiv)
|
|
bitmap_ior_into (vr0->equiv, vr1->equiv);
|
|
else if (vr1->equiv && !vr0->equiv)
|
|
bitmap_copy (vr0->equiv, vr1->equiv);
|
|
}
|
|
|
|
static void
|
|
vrp_intersect_ranges (value_range_t *vr0, value_range_t *vr1)
|
|
{
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
{
|
|
fprintf (dump_file, "Intersecting\n ");
|
|
dump_value_range (dump_file, vr0);
|
|
fprintf (dump_file, "\nand\n ");
|
|
dump_value_range (dump_file, vr1);
|
|
fprintf (dump_file, "\n");
|
|
}
|
|
vrp_intersect_ranges_1 (vr0, vr1);
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
{
|
|
fprintf (dump_file, "to\n ");
|
|
dump_value_range (dump_file, vr0);
|
|
fprintf (dump_file, "\n");
|
|
}
|
|
}
|
|
|
|
/* Meet operation for value ranges. Given two value ranges VR0 and
|
|
VR1, store in VR0 a range that contains both VR0 and VR1. This
|
|
may not be the smallest possible such range. */
|
|
|
|
static void
|
|
vrp_meet_1 (value_range_t *vr0, value_range_t *vr1)
|
|
{
|
|
value_range_t saved;
|
|
|
|
if (vr0->type == VR_UNDEFINED)
|
|
{
|
|
/* Drop equivalences. See PR53465. */
|
|
set_value_range (vr0, vr1->type, vr1->min, vr1->max, NULL);
|
|
return;
|
|
}
|
|
|
|
if (vr1->type == VR_UNDEFINED)
|
|
{
|
|
/* VR0 already has the resulting range, just drop equivalences.
|
|
See PR53465. */
|
|
if (vr0->equiv)
|
|
bitmap_clear (vr0->equiv);
|
|
return;
|
|
}
|
|
|
|
if (vr0->type == VR_VARYING)
|
|
{
|
|
/* Nothing to do. VR0 already has the resulting range. */
|
|
return;
|
|
}
|
|
|
|
if (vr1->type == VR_VARYING)
|
|
{
|
|
set_value_range_to_varying (vr0);
|
|
return;
|
|
}
|
|
|
|
saved = *vr0;
|
|
union_ranges (&vr0->type, &vr0->min, &vr0->max,
|
|
vr1->type, vr1->min, vr1->max);
|
|
if (vr0->type == VR_VARYING)
|
|
{
|
|
/* Failed to find an efficient meet. Before giving up and setting
|
|
the result to VARYING, see if we can at least derive a useful
|
|
anti-range. FIXME, all this nonsense about distinguishing
|
|
anti-ranges from ranges is necessary because of the odd
|
|
semantics of range_includes_zero_p and friends. */
|
|
if (((saved.type == VR_RANGE
|
|
&& range_includes_zero_p (saved.min, saved.max) == 0)
|
|
|| (saved.type == VR_ANTI_RANGE
|
|
&& range_includes_zero_p (saved.min, saved.max) == 1))
|
|
&& ((vr1->type == VR_RANGE
|
|
&& range_includes_zero_p (vr1->min, vr1->max) == 0)
|
|
|| (vr1->type == VR_ANTI_RANGE
|
|
&& range_includes_zero_p (vr1->min, vr1->max) == 1)))
|
|
{
|
|
set_value_range_to_nonnull (vr0, TREE_TYPE (saved.min));
|
|
|
|
/* Since this meet operation did not result from the meeting of
|
|
two equivalent names, VR0 cannot have any equivalences. */
|
|
if (vr0->equiv)
|
|
bitmap_clear (vr0->equiv);
|
|
return;
|
|
}
|
|
|
|
set_value_range_to_varying (vr0);
|
|
return;
|
|
}
|
|
set_and_canonicalize_value_range (vr0, vr0->type, vr0->min, vr0->max,
|
|
vr0->equiv);
|
|
if (vr0->type == VR_VARYING)
|
|
return;
|
|
|
|
/* The resulting set of equivalences is always the intersection of
|
|
the two sets. */
|
|
if (vr0->equiv && vr1->equiv && vr0->equiv != vr1->equiv)
|
|
bitmap_and_into (vr0->equiv, vr1->equiv);
|
|
else if (vr0->equiv && !vr1->equiv)
|
|
bitmap_clear (vr0->equiv);
|
|
}
|
|
|
|
static void
|
|
vrp_meet (value_range_t *vr0, value_range_t *vr1)
|
|
{
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
{
|
|
fprintf (dump_file, "Meeting\n ");
|
|
dump_value_range (dump_file, vr0);
|
|
fprintf (dump_file, "\nand\n ");
|
|
dump_value_range (dump_file, vr1);
|
|
fprintf (dump_file, "\n");
|
|
}
|
|
vrp_meet_1 (vr0, vr1);
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
{
|
|
fprintf (dump_file, "to\n ");
|
|
dump_value_range (dump_file, vr0);
|
|
fprintf (dump_file, "\n");
|
|
}
|
|
}
|
|
|
|
|
|
/* Visit all arguments for PHI node PHI that flow through executable
|
|
edges. If a valid value range can be derived from all the incoming
|
|
value ranges, set a new range for the LHS of PHI. */
|
|
|
|
static enum ssa_prop_result
|
|
vrp_visit_phi_node (gimple phi)
|
|
{
|
|
size_t i;
|
|
tree lhs = PHI_RESULT (phi);
|
|
value_range_t *lhs_vr = get_value_range (lhs);
|
|
value_range_t vr_result = VR_INITIALIZER;
|
|
bool first = true;
|
|
int edges, old_edges;
|
|
struct loop *l;
|
|
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
{
|
|
fprintf (dump_file, "\nVisiting PHI node: ");
|
|
print_gimple_stmt (dump_file, phi, 0, dump_flags);
|
|
}
|
|
|
|
edges = 0;
|
|
for (i = 0; i < gimple_phi_num_args (phi); i++)
|
|
{
|
|
edge e = gimple_phi_arg_edge (phi, i);
|
|
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
{
|
|
fprintf (dump_file,
|
|
"\n Argument #%d (%d -> %d %sexecutable)\n",
|
|
(int) i, e->src->index, e->dest->index,
|
|
(e->flags & EDGE_EXECUTABLE) ? "" : "not ");
|
|
}
|
|
|
|
if (e->flags & EDGE_EXECUTABLE)
|
|
{
|
|
tree arg = PHI_ARG_DEF (phi, i);
|
|
value_range_t vr_arg;
|
|
|
|
++edges;
|
|
|
|
if (TREE_CODE (arg) == SSA_NAME)
|
|
{
|
|
vr_arg = *(get_value_range (arg));
|
|
}
|
|
else
|
|
{
|
|
if (is_overflow_infinity (arg))
|
|
{
|
|
arg = copy_node (arg);
|
|
TREE_OVERFLOW (arg) = 0;
|
|
}
|
|
|
|
vr_arg.type = VR_RANGE;
|
|
vr_arg.min = arg;
|
|
vr_arg.max = arg;
|
|
vr_arg.equiv = NULL;
|
|
}
|
|
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
{
|
|
fprintf (dump_file, "\t");
|
|
print_generic_expr (dump_file, arg, dump_flags);
|
|
fprintf (dump_file, "\n\tValue: ");
|
|
dump_value_range (dump_file, &vr_arg);
|
|
fprintf (dump_file, "\n");
|
|
}
|
|
|
|
if (first)
|
|
copy_value_range (&vr_result, &vr_arg);
|
|
else
|
|
vrp_meet (&vr_result, &vr_arg);
|
|
first = false;
|
|
|
|
if (vr_result.type == VR_VARYING)
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (vr_result.type == VR_VARYING)
|
|
goto varying;
|
|
else if (vr_result.type == VR_UNDEFINED)
|
|
goto update_range;
|
|
|
|
old_edges = vr_phi_edge_counts[SSA_NAME_VERSION (lhs)];
|
|
vr_phi_edge_counts[SSA_NAME_VERSION (lhs)] = edges;
|
|
|
|
/* To prevent infinite iterations in the algorithm, derive ranges
|
|
when the new value is slightly bigger or smaller than the
|
|
previous one. We don't do this if we have seen a new executable
|
|
edge; this helps us avoid an overflow infinity for conditionals
|
|
which are not in a loop. If the old value-range was VR_UNDEFINED
|
|
use the updated range and iterate one more time. */
|
|
if (edges > 0
|
|
&& gimple_phi_num_args (phi) > 1
|
|
&& edges == old_edges
|
|
&& lhs_vr->type != VR_UNDEFINED)
|
|
{
|
|
int cmp_min = compare_values (lhs_vr->min, vr_result.min);
|
|
int cmp_max = compare_values (lhs_vr->max, vr_result.max);
|
|
|
|
/* For non VR_RANGE or for pointers fall back to varying if
|
|
the range changed. */
|
|
if ((lhs_vr->type != VR_RANGE || vr_result.type != VR_RANGE
|
|
|| POINTER_TYPE_P (TREE_TYPE (lhs)))
|
|
&& (cmp_min != 0 || cmp_max != 0))
|
|
goto varying;
|
|
|
|
/* If the new minimum is smaller or larger than the previous
|
|
one, go all the way to -INF. In the first case, to avoid
|
|
iterating millions of times to reach -INF, and in the
|
|
other case to avoid infinite bouncing between different
|
|
minimums. */
|
|
if (cmp_min > 0 || cmp_min < 0)
|
|
{
|
|
if (!needs_overflow_infinity (TREE_TYPE (vr_result.min))
|
|
|| !vrp_var_may_overflow (lhs, phi))
|
|
vr_result.min = TYPE_MIN_VALUE (TREE_TYPE (vr_result.min));
|
|
else if (supports_overflow_infinity (TREE_TYPE (vr_result.min)))
|
|
vr_result.min =
|
|
negative_overflow_infinity (TREE_TYPE (vr_result.min));
|
|
}
|
|
|
|
/* Similarly, if the new maximum is smaller or larger than
|
|
the previous one, go all the way to +INF. */
|
|
if (cmp_max < 0 || cmp_max > 0)
|
|
{
|
|
if (!needs_overflow_infinity (TREE_TYPE (vr_result.max))
|
|
|| !vrp_var_may_overflow (lhs, phi))
|
|
vr_result.max = TYPE_MAX_VALUE (TREE_TYPE (vr_result.max));
|
|
else if (supports_overflow_infinity (TREE_TYPE (vr_result.max)))
|
|
vr_result.max =
|
|
positive_overflow_infinity (TREE_TYPE (vr_result.max));
|
|
}
|
|
|
|
/* If we dropped either bound to +-INF then if this is a loop
|
|
PHI node SCEV may known more about its value-range. */
|
|
if ((cmp_min > 0 || cmp_min < 0
|
|
|| cmp_max < 0 || cmp_max > 0)
|
|
&& current_loops
|
|
&& (l = loop_containing_stmt (phi))
|
|
&& l->header == gimple_bb (phi))
|
|
adjust_range_with_scev (&vr_result, l, phi, lhs);
|
|
|
|
/* If we will end up with a (-INF, +INF) range, set it to
|
|
VARYING. Same if the previous max value was invalid for
|
|
the type and we end up with vr_result.min > vr_result.max. */
|
|
if ((vrp_val_is_max (vr_result.max)
|
|
&& vrp_val_is_min (vr_result.min))
|
|
|| compare_values (vr_result.min,
|
|
vr_result.max) > 0)
|
|
goto varying;
|
|
}
|
|
|
|
/* If the new range is different than the previous value, keep
|
|
iterating. */
|
|
update_range:
|
|
if (update_value_range (lhs, &vr_result))
|
|
{
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
{
|
|
fprintf (dump_file, "Found new range for ");
|
|
print_generic_expr (dump_file, lhs, 0);
|
|
fprintf (dump_file, ": ");
|
|
dump_value_range (dump_file, &vr_result);
|
|
fprintf (dump_file, "\n\n");
|
|
}
|
|
|
|
return SSA_PROP_INTERESTING;
|
|
}
|
|
|
|
/* Nothing changed, don't add outgoing edges. */
|
|
return SSA_PROP_NOT_INTERESTING;
|
|
|
|
/* No match found. Set the LHS to VARYING. */
|
|
varying:
|
|
set_value_range_to_varying (lhs_vr);
|
|
return SSA_PROP_VARYING;
|
|
}
|
|
|
|
/* Simplify boolean operations if the source is known
|
|
to be already a boolean. */
|
|
static bool
|
|
simplify_truth_ops_using_ranges (gimple_stmt_iterator *gsi, gimple stmt)
|
|
{
|
|
enum tree_code rhs_code = gimple_assign_rhs_code (stmt);
|
|
tree lhs, op0, op1;
|
|
bool need_conversion;
|
|
|
|
/* We handle only !=/== case here. */
|
|
gcc_assert (rhs_code == EQ_EXPR || rhs_code == NE_EXPR);
|
|
|
|
op0 = gimple_assign_rhs1 (stmt);
|
|
if (!op_with_boolean_value_range_p (op0))
|
|
return false;
|
|
|
|
op1 = gimple_assign_rhs2 (stmt);
|
|
if (!op_with_boolean_value_range_p (op1))
|
|
return false;
|
|
|
|
/* Reduce number of cases to handle to NE_EXPR. As there is no
|
|
BIT_XNOR_EXPR we cannot replace A == B with a single statement. */
|
|
if (rhs_code == EQ_EXPR)
|
|
{
|
|
if (TREE_CODE (op1) == INTEGER_CST)
|
|
op1 = int_const_binop (BIT_XOR_EXPR, op1, integer_one_node);
|
|
else
|
|
return false;
|
|
}
|
|
|
|
lhs = gimple_assign_lhs (stmt);
|
|
need_conversion
|
|
= !useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (op0));
|
|
|
|
/* Make sure to not sign-extend a 1-bit 1 when converting the result. */
|
|
if (need_conversion
|
|
&& !TYPE_UNSIGNED (TREE_TYPE (op0))
|
|
&& TYPE_PRECISION (TREE_TYPE (op0)) == 1
|
|
&& TYPE_PRECISION (TREE_TYPE (lhs)) > 1)
|
|
return false;
|
|
|
|
/* For A != 0 we can substitute A itself. */
|
|
if (integer_zerop (op1))
|
|
gimple_assign_set_rhs_with_ops (gsi,
|
|
need_conversion
|
|
? NOP_EXPR : TREE_CODE (op0),
|
|
op0, NULL_TREE);
|
|
/* For A != B we substitute A ^ B. Either with conversion. */
|
|
else if (need_conversion)
|
|
{
|
|
tree tem = make_ssa_name (TREE_TYPE (op0), NULL);
|
|
gimple newop = gimple_build_assign_with_ops (BIT_XOR_EXPR, tem, op0, op1);
|
|
gsi_insert_before (gsi, newop, GSI_SAME_STMT);
|
|
gimple_assign_set_rhs_with_ops (gsi, NOP_EXPR, tem, NULL_TREE);
|
|
}
|
|
/* Or without. */
|
|
else
|
|
gimple_assign_set_rhs_with_ops (gsi, BIT_XOR_EXPR, op0, op1);
|
|
update_stmt (gsi_stmt (*gsi));
|
|
|
|
return true;
|
|
}
|
|
|
|
/* Simplify a division or modulo operator to a right shift or
|
|
bitwise and if the first operand is unsigned or is greater
|
|
than zero and the second operand is an exact power of two. */
|
|
|
|
static bool
|
|
simplify_div_or_mod_using_ranges (gimple stmt)
|
|
{
|
|
enum tree_code rhs_code = gimple_assign_rhs_code (stmt);
|
|
tree val = NULL;
|
|
tree op0 = gimple_assign_rhs1 (stmt);
|
|
tree op1 = gimple_assign_rhs2 (stmt);
|
|
value_range_t *vr = get_value_range (gimple_assign_rhs1 (stmt));
|
|
|
|
if (TYPE_UNSIGNED (TREE_TYPE (op0)))
|
|
{
|
|
val = integer_one_node;
|
|
}
|
|
else
|
|
{
|
|
bool sop = false;
|
|
|
|
val = compare_range_with_value (GE_EXPR, vr, integer_zero_node, &sop);
|
|
|
|
if (val
|
|
&& sop
|
|
&& integer_onep (val)
|
|
&& issue_strict_overflow_warning (WARN_STRICT_OVERFLOW_MISC))
|
|
{
|
|
location_t location;
|
|
|
|
if (!gimple_has_location (stmt))
|
|
location = input_location;
|
|
else
|
|
location = gimple_location (stmt);
|
|
warning_at (location, OPT_Wstrict_overflow,
|
|
"assuming signed overflow does not occur when "
|
|
"simplifying %</%> or %<%%%> to %<>>%> or %<&%>");
|
|
}
|
|
}
|
|
|
|
if (val && integer_onep (val))
|
|
{
|
|
tree t;
|
|
|
|
if (rhs_code == TRUNC_DIV_EXPR)
|
|
{
|
|
t = build_int_cst (integer_type_node, tree_log2 (op1));
|
|
gimple_assign_set_rhs_code (stmt, RSHIFT_EXPR);
|
|
gimple_assign_set_rhs1 (stmt, op0);
|
|
gimple_assign_set_rhs2 (stmt, t);
|
|
}
|
|
else
|
|
{
|
|
t = build_int_cst (TREE_TYPE (op1), 1);
|
|
t = int_const_binop (MINUS_EXPR, op1, t);
|
|
t = fold_convert (TREE_TYPE (op0), t);
|
|
|
|
gimple_assign_set_rhs_code (stmt, BIT_AND_EXPR);
|
|
gimple_assign_set_rhs1 (stmt, op0);
|
|
gimple_assign_set_rhs2 (stmt, t);
|
|
}
|
|
|
|
update_stmt (stmt);
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/* If the operand to an ABS_EXPR is >= 0, then eliminate the
|
|
ABS_EXPR. If the operand is <= 0, then simplify the
|
|
ABS_EXPR into a NEGATE_EXPR. */
|
|
|
|
static bool
|
|
simplify_abs_using_ranges (gimple stmt)
|
|
{
|
|
tree val = NULL;
|
|
tree op = gimple_assign_rhs1 (stmt);
|
|
tree type = TREE_TYPE (op);
|
|
value_range_t *vr = get_value_range (op);
|
|
|
|
if (TYPE_UNSIGNED (type))
|
|
{
|
|
val = integer_zero_node;
|
|
}
|
|
else if (vr)
|
|
{
|
|
bool sop = false;
|
|
|
|
val = compare_range_with_value (LE_EXPR, vr, integer_zero_node, &sop);
|
|
if (!val)
|
|
{
|
|
sop = false;
|
|
val = compare_range_with_value (GE_EXPR, vr, integer_zero_node,
|
|
&sop);
|
|
|
|
if (val)
|
|
{
|
|
if (integer_zerop (val))
|
|
val = integer_one_node;
|
|
else if (integer_onep (val))
|
|
val = integer_zero_node;
|
|
}
|
|
}
|
|
|
|
if (val
|
|
&& (integer_onep (val) || integer_zerop (val)))
|
|
{
|
|
if (sop && issue_strict_overflow_warning (WARN_STRICT_OVERFLOW_MISC))
|
|
{
|
|
location_t location;
|
|
|
|
if (!gimple_has_location (stmt))
|
|
location = input_location;
|
|
else
|
|
location = gimple_location (stmt);
|
|
warning_at (location, OPT_Wstrict_overflow,
|
|
"assuming signed overflow does not occur when "
|
|
"simplifying %<abs (X)%> to %<X%> or %<-X%>");
|
|
}
|
|
|
|
gimple_assign_set_rhs1 (stmt, op);
|
|
if (integer_onep (val))
|
|
gimple_assign_set_rhs_code (stmt, NEGATE_EXPR);
|
|
else
|
|
gimple_assign_set_rhs_code (stmt, SSA_NAME);
|
|
update_stmt (stmt);
|
|
return true;
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/* Optimize away redundant BIT_AND_EXPR and BIT_IOR_EXPR.
|
|
If all the bits that are being cleared by & are already
|
|
known to be zero from VR, or all the bits that are being
|
|
set by | are already known to be one from VR, the bit
|
|
operation is redundant. */
|
|
|
|
static bool
|
|
simplify_bit_ops_using_ranges (gimple_stmt_iterator *gsi, gimple stmt)
|
|
{
|
|
tree op0 = gimple_assign_rhs1 (stmt);
|
|
tree op1 = gimple_assign_rhs2 (stmt);
|
|
tree op = NULL_TREE;
|
|
value_range_t vr0 = VR_INITIALIZER;
|
|
value_range_t vr1 = VR_INITIALIZER;
|
|
double_int may_be_nonzero0, may_be_nonzero1;
|
|
double_int must_be_nonzero0, must_be_nonzero1;
|
|
double_int mask;
|
|
|
|
if (TREE_CODE (op0) == SSA_NAME)
|
|
vr0 = *(get_value_range (op0));
|
|
else if (is_gimple_min_invariant (op0))
|
|
set_value_range_to_value (&vr0, op0, NULL);
|
|
else
|
|
return false;
|
|
|
|
if (TREE_CODE (op1) == SSA_NAME)
|
|
vr1 = *(get_value_range (op1));
|
|
else if (is_gimple_min_invariant (op1))
|
|
set_value_range_to_value (&vr1, op1, NULL);
|
|
else
|
|
return false;
|
|
|
|
if (!zero_nonzero_bits_from_vr (&vr0, &may_be_nonzero0, &must_be_nonzero0))
|
|
return false;
|
|
if (!zero_nonzero_bits_from_vr (&vr1, &may_be_nonzero1, &must_be_nonzero1))
|
|
return false;
|
|
|
|
switch (gimple_assign_rhs_code (stmt))
|
|
{
|
|
case BIT_AND_EXPR:
|
|
mask = may_be_nonzero0.and_not (must_be_nonzero1);
|
|
if (mask.is_zero ())
|
|
{
|
|
op = op0;
|
|
break;
|
|
}
|
|
mask = may_be_nonzero1.and_not (must_be_nonzero0);
|
|
if (mask.is_zero ())
|
|
{
|
|
op = op1;
|
|
break;
|
|
}
|
|
break;
|
|
case BIT_IOR_EXPR:
|
|
mask = may_be_nonzero0.and_not (must_be_nonzero1);
|
|
if (mask.is_zero ())
|
|
{
|
|
op = op1;
|
|
break;
|
|
}
|
|
mask = may_be_nonzero1.and_not (must_be_nonzero0);
|
|
if (mask.is_zero ())
|
|
{
|
|
op = op0;
|
|
break;
|
|
}
|
|
break;
|
|
default:
|
|
gcc_unreachable ();
|
|
}
|
|
|
|
if (op == NULL_TREE)
|
|
return false;
|
|
|
|
gimple_assign_set_rhs_with_ops (gsi, TREE_CODE (op), op, NULL);
|
|
update_stmt (gsi_stmt (*gsi));
|
|
return true;
|
|
}
|
|
|
|
/* We are comparing trees OP0 and OP1 using COND_CODE. OP0 has
|
|
a known value range VR.
|
|
|
|
If there is one and only one value which will satisfy the
|
|
conditional, then return that value. Else return NULL. */
|
|
|
|
static tree
|
|
test_for_singularity (enum tree_code cond_code, tree op0,
|
|
tree op1, value_range_t *vr)
|
|
{
|
|
tree min = NULL;
|
|
tree max = NULL;
|
|
|
|
/* Extract minimum/maximum values which satisfy the
|
|
the conditional as it was written. */
|
|
if (cond_code == LE_EXPR || cond_code == LT_EXPR)
|
|
{
|
|
/* This should not be negative infinity; there is no overflow
|
|
here. */
|
|
min = TYPE_MIN_VALUE (TREE_TYPE (op0));
|
|
|
|
max = op1;
|
|
if (cond_code == LT_EXPR && !is_overflow_infinity (max))
|
|
{
|
|
tree one = build_int_cst (TREE_TYPE (op0), 1);
|
|
max = fold_build2 (MINUS_EXPR, TREE_TYPE (op0), max, one);
|
|
if (EXPR_P (max))
|
|
TREE_NO_WARNING (max) = 1;
|
|
}
|
|
}
|
|
else if (cond_code == GE_EXPR || cond_code == GT_EXPR)
|
|
{
|
|
/* This should not be positive infinity; there is no overflow
|
|
here. */
|
|
max = TYPE_MAX_VALUE (TREE_TYPE (op0));
|
|
|
|
min = op1;
|
|
if (cond_code == GT_EXPR && !is_overflow_infinity (min))
|
|
{
|
|
tree one = build_int_cst (TREE_TYPE (op0), 1);
|
|
min = fold_build2 (PLUS_EXPR, TREE_TYPE (op0), min, one);
|
|
if (EXPR_P (min))
|
|
TREE_NO_WARNING (min) = 1;
|
|
}
|
|
}
|
|
|
|
/* Now refine the minimum and maximum values using any
|
|
value range information we have for op0. */
|
|
if (min && max)
|
|
{
|
|
if (compare_values (vr->min, min) == 1)
|
|
min = vr->min;
|
|
if (compare_values (vr->max, max) == -1)
|
|
max = vr->max;
|
|
|
|
/* If the new min/max values have converged to a single value,
|
|
then there is only one value which can satisfy the condition,
|
|
return that value. */
|
|
if (operand_equal_p (min, max, 0) && is_gimple_min_invariant (min))
|
|
return min;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
/* Simplify a conditional using a relational operator to an equality
|
|
test if the range information indicates only one value can satisfy
|
|
the original conditional. */
|
|
|
|
static bool
|
|
simplify_cond_using_ranges (gimple stmt)
|
|
{
|
|
tree op0 = gimple_cond_lhs (stmt);
|
|
tree op1 = gimple_cond_rhs (stmt);
|
|
enum tree_code cond_code = gimple_cond_code (stmt);
|
|
|
|
if (cond_code != NE_EXPR
|
|
&& cond_code != EQ_EXPR
|
|
&& TREE_CODE (op0) == SSA_NAME
|
|
&& INTEGRAL_TYPE_P (TREE_TYPE (op0))
|
|
&& is_gimple_min_invariant (op1))
|
|
{
|
|
value_range_t *vr = get_value_range (op0);
|
|
|
|
/* If we have range information for OP0, then we might be
|
|
able to simplify this conditional. */
|
|
if (vr->type == VR_RANGE)
|
|
{
|
|
tree new_tree = test_for_singularity (cond_code, op0, op1, vr);
|
|
|
|
if (new_tree)
|
|
{
|
|
if (dump_file)
|
|
{
|
|
fprintf (dump_file, "Simplified relational ");
|
|
print_gimple_stmt (dump_file, stmt, 0, 0);
|
|
fprintf (dump_file, " into ");
|
|
}
|
|
|
|
gimple_cond_set_code (stmt, EQ_EXPR);
|
|
gimple_cond_set_lhs (stmt, op0);
|
|
gimple_cond_set_rhs (stmt, new_tree);
|
|
|
|
update_stmt (stmt);
|
|
|
|
if (dump_file)
|
|
{
|
|
print_gimple_stmt (dump_file, stmt, 0, 0);
|
|
fprintf (dump_file, "\n");
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
/* Try again after inverting the condition. We only deal
|
|
with integral types here, so no need to worry about
|
|
issues with inverting FP comparisons. */
|
|
cond_code = invert_tree_comparison (cond_code, false);
|
|
new_tree = test_for_singularity (cond_code, op0, op1, vr);
|
|
|
|
if (new_tree)
|
|
{
|
|
if (dump_file)
|
|
{
|
|
fprintf (dump_file, "Simplified relational ");
|
|
print_gimple_stmt (dump_file, stmt, 0, 0);
|
|
fprintf (dump_file, " into ");
|
|
}
|
|
|
|
gimple_cond_set_code (stmt, NE_EXPR);
|
|
gimple_cond_set_lhs (stmt, op0);
|
|
gimple_cond_set_rhs (stmt, new_tree);
|
|
|
|
update_stmt (stmt);
|
|
|
|
if (dump_file)
|
|
{
|
|
print_gimple_stmt (dump_file, stmt, 0, 0);
|
|
fprintf (dump_file, "\n");
|
|
}
|
|
|
|
return true;
|
|
}
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/* Simplify a switch statement using the value range of the switch
|
|
argument. */
|
|
|
|
static bool
|
|
simplify_switch_using_ranges (gimple stmt)
|
|
{
|
|
tree op = gimple_switch_index (stmt);
|
|
value_range_t *vr;
|
|
bool take_default;
|
|
edge e;
|
|
edge_iterator ei;
|
|
size_t i = 0, j = 0, n, n2;
|
|
tree vec2;
|
|
switch_update su;
|
|
size_t k = 1, l = 0;
|
|
|
|
if (TREE_CODE (op) == SSA_NAME)
|
|
{
|
|
vr = get_value_range (op);
|
|
|
|
/* We can only handle integer ranges. */
|
|
if ((vr->type != VR_RANGE
|
|
&& vr->type != VR_ANTI_RANGE)
|
|
|| symbolic_range_p (vr))
|
|
return false;
|
|
|
|
/* Find case label for min/max of the value range. */
|
|
take_default = !find_case_label_ranges (stmt, vr, &i, &j, &k, &l);
|
|
}
|
|
else if (TREE_CODE (op) == INTEGER_CST)
|
|
{
|
|
take_default = !find_case_label_index (stmt, 1, op, &i);
|
|
if (take_default)
|
|
{
|
|
i = 1;
|
|
j = 0;
|
|
}
|
|
else
|
|
{
|
|
j = i;
|
|
}
|
|
}
|
|
else
|
|
return false;
|
|
|
|
n = gimple_switch_num_labels (stmt);
|
|
|
|
/* Bail out if this is just all edges taken. */
|
|
if (i == 1
|
|
&& j == n - 1
|
|
&& take_default)
|
|
return false;
|
|
|
|
/* Build a new vector of taken case labels. */
|
|
vec2 = make_tree_vec (j - i + 1 + l - k + 1 + (int)take_default);
|
|
n2 = 0;
|
|
|
|
/* Add the default edge, if necessary. */
|
|
if (take_default)
|
|
TREE_VEC_ELT (vec2, n2++) = gimple_switch_default_label (stmt);
|
|
|
|
for (; i <= j; ++i, ++n2)
|
|
TREE_VEC_ELT (vec2, n2) = gimple_switch_label (stmt, i);
|
|
|
|
for (; k <= l; ++k, ++n2)
|
|
TREE_VEC_ELT (vec2, n2) = gimple_switch_label (stmt, k);
|
|
|
|
/* Mark needed edges. */
|
|
for (i = 0; i < n2; ++i)
|
|
{
|
|
e = find_edge (gimple_bb (stmt),
|
|
label_to_block (CASE_LABEL (TREE_VEC_ELT (vec2, i))));
|
|
e->aux = (void *)-1;
|
|
}
|
|
|
|
/* Queue not needed edges for later removal. */
|
|
FOR_EACH_EDGE (e, ei, gimple_bb (stmt)->succs)
|
|
{
|
|
if (e->aux == (void *)-1)
|
|
{
|
|
e->aux = NULL;
|
|
continue;
|
|
}
|
|
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
{
|
|
fprintf (dump_file, "removing unreachable case label\n");
|
|
}
|
|
to_remove_edges.safe_push (e);
|
|
e->flags &= ~EDGE_EXECUTABLE;
|
|
}
|
|
|
|
/* And queue an update for the stmt. */
|
|
su.stmt = stmt;
|
|
su.vec = vec2;
|
|
to_update_switch_stmts.safe_push (su);
|
|
return false;
|
|
}
|
|
|
|
/* Simplify an integral conversion from an SSA name in STMT. */
|
|
|
|
static bool
|
|
simplify_conversion_using_ranges (gimple stmt)
|
|
{
|
|
tree innerop, middleop, finaltype;
|
|
gimple def_stmt;
|
|
value_range_t *innervr;
|
|
bool inner_unsigned_p, middle_unsigned_p, final_unsigned_p;
|
|
unsigned inner_prec, middle_prec, final_prec;
|
|
double_int innermin, innermed, innermax, middlemin, middlemed, middlemax;
|
|
|
|
finaltype = TREE_TYPE (gimple_assign_lhs (stmt));
|
|
if (!INTEGRAL_TYPE_P (finaltype))
|
|
return false;
|
|
middleop = gimple_assign_rhs1 (stmt);
|
|
def_stmt = SSA_NAME_DEF_STMT (middleop);
|
|
if (!is_gimple_assign (def_stmt)
|
|
|| !CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt)))
|
|
return false;
|
|
innerop = gimple_assign_rhs1 (def_stmt);
|
|
if (TREE_CODE (innerop) != SSA_NAME)
|
|
return false;
|
|
|
|
/* Get the value-range of the inner operand. */
|
|
innervr = get_value_range (innerop);
|
|
if (innervr->type != VR_RANGE
|
|
|| TREE_CODE (innervr->min) != INTEGER_CST
|
|
|| TREE_CODE (innervr->max) != INTEGER_CST)
|
|
return false;
|
|
|
|
/* Simulate the conversion chain to check if the result is equal if
|
|
the middle conversion is removed. */
|
|
innermin = tree_to_double_int (innervr->min);
|
|
innermax = tree_to_double_int (innervr->max);
|
|
|
|
inner_prec = TYPE_PRECISION (TREE_TYPE (innerop));
|
|
middle_prec = TYPE_PRECISION (TREE_TYPE (middleop));
|
|
final_prec = TYPE_PRECISION (finaltype);
|
|
|
|
/* If the first conversion is not injective, the second must not
|
|
be widening. */
|
|
if ((innermax - innermin).ugt (double_int::mask (middle_prec))
|
|
&& middle_prec < final_prec)
|
|
return false;
|
|
/* We also want a medium value so that we can track the effect that
|
|
narrowing conversions with sign change have. */
|
|
inner_unsigned_p = TYPE_UNSIGNED (TREE_TYPE (innerop));
|
|
if (inner_unsigned_p)
|
|
innermed = double_int::mask (inner_prec).lrshift (1, inner_prec);
|
|
else
|
|
innermed = double_int_zero;
|
|
if (innermin.cmp (innermed, inner_unsigned_p) >= 0
|
|
|| innermed.cmp (innermax, inner_unsigned_p) >= 0)
|
|
innermed = innermin;
|
|
|
|
middle_unsigned_p = TYPE_UNSIGNED (TREE_TYPE (middleop));
|
|
middlemin = innermin.ext (middle_prec, middle_unsigned_p);
|
|
middlemed = innermed.ext (middle_prec, middle_unsigned_p);
|
|
middlemax = innermax.ext (middle_prec, middle_unsigned_p);
|
|
|
|
/* Require that the final conversion applied to both the original
|
|
and the intermediate range produces the same result. */
|
|
final_unsigned_p = TYPE_UNSIGNED (finaltype);
|
|
if (middlemin.ext (final_prec, final_unsigned_p)
|
|
!= innermin.ext (final_prec, final_unsigned_p)
|
|
|| middlemed.ext (final_prec, final_unsigned_p)
|
|
!= innermed.ext (final_prec, final_unsigned_p)
|
|
|| middlemax.ext (final_prec, final_unsigned_p)
|
|
!= innermax.ext (final_prec, final_unsigned_p))
|
|
return false;
|
|
|
|
gimple_assign_set_rhs1 (stmt, innerop);
|
|
update_stmt (stmt);
|
|
return true;
|
|
}
|
|
|
|
/* Return whether the value range *VR fits in an integer type specified
|
|
by PRECISION and UNSIGNED_P. */
|
|
|
|
static bool
|
|
range_fits_type_p (value_range_t *vr, unsigned precision, bool unsigned_p)
|
|
{
|
|
tree src_type;
|
|
unsigned src_precision;
|
|
double_int tem;
|
|
|
|
/* We can only handle integral and pointer types. */
|
|
src_type = TREE_TYPE (vr->min);
|
|
if (!INTEGRAL_TYPE_P (src_type)
|
|
&& !POINTER_TYPE_P (src_type))
|
|
return false;
|
|
|
|
/* An extension is always fine, so is an identity transform. */
|
|
src_precision = TYPE_PRECISION (TREE_TYPE (vr->min));
|
|
if (src_precision < precision
|
|
|| (src_precision == precision
|
|
&& TYPE_UNSIGNED (src_type) == unsigned_p))
|
|
return true;
|
|
|
|
/* Now we can only handle ranges with constant bounds. */
|
|
if (vr->type != VR_RANGE
|
|
|| TREE_CODE (vr->min) != INTEGER_CST
|
|
|| TREE_CODE (vr->max) != INTEGER_CST)
|
|
return false;
|
|
|
|
/* For precision-preserving sign-changes the MSB of the double-int
|
|
has to be clear. */
|
|
if (src_precision == precision
|
|
&& (TREE_INT_CST_HIGH (vr->min) | TREE_INT_CST_HIGH (vr->max)) < 0)
|
|
return false;
|
|
|
|
/* Then we can perform the conversion on both ends and compare
|
|
the result for equality. */
|
|
tem = tree_to_double_int (vr->min).ext (precision, unsigned_p);
|
|
if (tree_to_double_int (vr->min) != tem)
|
|
return false;
|
|
tem = tree_to_double_int (vr->max).ext (precision, unsigned_p);
|
|
if (tree_to_double_int (vr->max) != tem)
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
/* Simplify a conversion from integral SSA name to float in STMT. */
|
|
|
|
static bool
|
|
simplify_float_conversion_using_ranges (gimple_stmt_iterator *gsi, gimple stmt)
|
|
{
|
|
tree rhs1 = gimple_assign_rhs1 (stmt);
|
|
value_range_t *vr = get_value_range (rhs1);
|
|
enum machine_mode fltmode = TYPE_MODE (TREE_TYPE (gimple_assign_lhs (stmt)));
|
|
enum machine_mode mode;
|
|
tree tem;
|
|
gimple conv;
|
|
|
|
/* We can only handle constant ranges. */
|
|
if (vr->type != VR_RANGE
|
|
|| TREE_CODE (vr->min) != INTEGER_CST
|
|
|| TREE_CODE (vr->max) != INTEGER_CST)
|
|
return false;
|
|
|
|
/* First check if we can use a signed type in place of an unsigned. */
|
|
if (TYPE_UNSIGNED (TREE_TYPE (rhs1))
|
|
&& (can_float_p (fltmode, TYPE_MODE (TREE_TYPE (rhs1)), 0)
|
|
!= CODE_FOR_nothing)
|
|
&& range_fits_type_p (vr, GET_MODE_PRECISION
|
|
(TYPE_MODE (TREE_TYPE (rhs1))), 0))
|
|
mode = TYPE_MODE (TREE_TYPE (rhs1));
|
|
/* If we can do the conversion in the current input mode do nothing. */
|
|
else if (can_float_p (fltmode, TYPE_MODE (TREE_TYPE (rhs1)),
|
|
TYPE_UNSIGNED (TREE_TYPE (rhs1))))
|
|
return false;
|
|
/* Otherwise search for a mode we can use, starting from the narrowest
|
|
integer mode available. */
|
|
else
|
|
{
|
|
mode = GET_CLASS_NARROWEST_MODE (MODE_INT);
|
|
do
|
|
{
|
|
/* If we cannot do a signed conversion to float from mode
|
|
or if the value-range does not fit in the signed type
|
|
try with a wider mode. */
|
|
if (can_float_p (fltmode, mode, 0) != CODE_FOR_nothing
|
|
&& range_fits_type_p (vr, GET_MODE_PRECISION (mode), 0))
|
|
break;
|
|
|
|
mode = GET_MODE_WIDER_MODE (mode);
|
|
/* But do not widen the input. Instead leave that to the
|
|
optabs expansion code. */
|
|
if (GET_MODE_PRECISION (mode) > TYPE_PRECISION (TREE_TYPE (rhs1)))
|
|
return false;
|
|
}
|
|
while (mode != VOIDmode);
|
|
if (mode == VOIDmode)
|
|
return false;
|
|
}
|
|
|
|
/* It works, insert a truncation or sign-change before the
|
|
float conversion. */
|
|
tem = make_ssa_name (build_nonstandard_integer_type
|
|
(GET_MODE_PRECISION (mode), 0), NULL);
|
|
conv = gimple_build_assign_with_ops (NOP_EXPR, tem, rhs1, NULL_TREE);
|
|
gsi_insert_before (gsi, conv, GSI_SAME_STMT);
|
|
gimple_assign_set_rhs1 (stmt, tem);
|
|
update_stmt (stmt);
|
|
|
|
return true;
|
|
}
|
|
|
|
/* Simplify STMT using ranges if possible. */
|
|
|
|
static bool
|
|
simplify_stmt_using_ranges (gimple_stmt_iterator *gsi)
|
|
{
|
|
gimple stmt = gsi_stmt (*gsi);
|
|
if (is_gimple_assign (stmt))
|
|
{
|
|
enum tree_code rhs_code = gimple_assign_rhs_code (stmt);
|
|
tree rhs1 = gimple_assign_rhs1 (stmt);
|
|
|
|
switch (rhs_code)
|
|
{
|
|
case EQ_EXPR:
|
|
case NE_EXPR:
|
|
/* Transform EQ_EXPR, NE_EXPR into BIT_XOR_EXPR or identity
|
|
if the RHS is zero or one, and the LHS are known to be boolean
|
|
values. */
|
|
if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1)))
|
|
return simplify_truth_ops_using_ranges (gsi, stmt);
|
|
break;
|
|
|
|
/* Transform TRUNC_DIV_EXPR and TRUNC_MOD_EXPR into RSHIFT_EXPR
|
|
and BIT_AND_EXPR respectively if the first operand is greater
|
|
than zero and the second operand is an exact power of two. */
|
|
case TRUNC_DIV_EXPR:
|
|
case TRUNC_MOD_EXPR:
|
|
if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1))
|
|
&& integer_pow2p (gimple_assign_rhs2 (stmt)))
|
|
return simplify_div_or_mod_using_ranges (stmt);
|
|
break;
|
|
|
|
/* Transform ABS (X) into X or -X as appropriate. */
|
|
case ABS_EXPR:
|
|
if (TREE_CODE (rhs1) == SSA_NAME
|
|
&& INTEGRAL_TYPE_P (TREE_TYPE (rhs1)))
|
|
return simplify_abs_using_ranges (stmt);
|
|
break;
|
|
|
|
case BIT_AND_EXPR:
|
|
case BIT_IOR_EXPR:
|
|
/* Optimize away BIT_AND_EXPR and BIT_IOR_EXPR
|
|
if all the bits being cleared are already cleared or
|
|
all the bits being set are already set. */
|
|
if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1)))
|
|
return simplify_bit_ops_using_ranges (gsi, stmt);
|
|
break;
|
|
|
|
CASE_CONVERT:
|
|
if (TREE_CODE (rhs1) == SSA_NAME
|
|
&& INTEGRAL_TYPE_P (TREE_TYPE (rhs1)))
|
|
return simplify_conversion_using_ranges (stmt);
|
|
break;
|
|
|
|
case FLOAT_EXPR:
|
|
if (TREE_CODE (rhs1) == SSA_NAME
|
|
&& INTEGRAL_TYPE_P (TREE_TYPE (rhs1)))
|
|
return simplify_float_conversion_using_ranges (gsi, stmt);
|
|
break;
|
|
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
else if (gimple_code (stmt) == GIMPLE_COND)
|
|
return simplify_cond_using_ranges (stmt);
|
|
else if (gimple_code (stmt) == GIMPLE_SWITCH)
|
|
return simplify_switch_using_ranges (stmt);
|
|
|
|
return false;
|
|
}
|
|
|
|
/* If the statement pointed by SI has a predicate whose value can be
|
|
computed using the value range information computed by VRP, compute
|
|
its value and return true. Otherwise, return false. */
|
|
|
|
static bool
|
|
fold_predicate_in (gimple_stmt_iterator *si)
|
|
{
|
|
bool assignment_p = false;
|
|
tree val;
|
|
gimple stmt = gsi_stmt (*si);
|
|
|
|
if (is_gimple_assign (stmt)
|
|
&& TREE_CODE_CLASS (gimple_assign_rhs_code (stmt)) == tcc_comparison)
|
|
{
|
|
assignment_p = true;
|
|
val = vrp_evaluate_conditional (gimple_assign_rhs_code (stmt),
|
|
gimple_assign_rhs1 (stmt),
|
|
gimple_assign_rhs2 (stmt),
|
|
stmt);
|
|
}
|
|
else if (gimple_code (stmt) == GIMPLE_COND)
|
|
val = vrp_evaluate_conditional (gimple_cond_code (stmt),
|
|
gimple_cond_lhs (stmt),
|
|
gimple_cond_rhs (stmt),
|
|
stmt);
|
|
else
|
|
return false;
|
|
|
|
if (val)
|
|
{
|
|
if (assignment_p)
|
|
val = fold_convert (gimple_expr_type (stmt), val);
|
|
|
|
if (dump_file)
|
|
{
|
|
fprintf (dump_file, "Folding predicate ");
|
|
print_gimple_expr (dump_file, stmt, 0, 0);
|
|
fprintf (dump_file, " to ");
|
|
print_generic_expr (dump_file, val, 0);
|
|
fprintf (dump_file, "\n");
|
|
}
|
|
|
|
if (is_gimple_assign (stmt))
|
|
gimple_assign_set_rhs_from_tree (si, val);
|
|
else
|
|
{
|
|
gcc_assert (gimple_code (stmt) == GIMPLE_COND);
|
|
if (integer_zerop (val))
|
|
gimple_cond_make_false (stmt);
|
|
else if (integer_onep (val))
|
|
gimple_cond_make_true (stmt);
|
|
else
|
|
gcc_unreachable ();
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/* Callback for substitute_and_fold folding the stmt at *SI. */
|
|
|
|
static bool
|
|
vrp_fold_stmt (gimple_stmt_iterator *si)
|
|
{
|
|
if (fold_predicate_in (si))
|
|
return true;
|
|
|
|
return simplify_stmt_using_ranges (si);
|
|
}
|
|
|
|
/* Stack of dest,src equivalency pairs that need to be restored after
|
|
each attempt to thread a block's incoming edge to an outgoing edge.
|
|
|
|
A NULL entry is used to mark the end of pairs which need to be
|
|
restored. */
|
|
static vec<tree> equiv_stack;
|
|
|
|
/* A trivial wrapper so that we can present the generic jump threading
|
|
code with a simple API for simplifying statements. STMT is the
|
|
statement we want to simplify, WITHIN_STMT provides the location
|
|
for any overflow warnings. */
|
|
|
|
static tree
|
|
simplify_stmt_for_jump_threading (gimple stmt, gimple within_stmt)
|
|
{
|
|
/* We only use VRP information to simplify conditionals. This is
|
|
overly conservative, but it's unclear if doing more would be
|
|
worth the compile time cost. */
|
|
if (gimple_code (stmt) != GIMPLE_COND)
|
|
return NULL;
|
|
|
|
return vrp_evaluate_conditional (gimple_cond_code (stmt),
|
|
gimple_cond_lhs (stmt),
|
|
gimple_cond_rhs (stmt), within_stmt);
|
|
}
|
|
|
|
/* Blocks which have more than one predecessor and more than
|
|
one successor present jump threading opportunities, i.e.,
|
|
when the block is reached from a specific predecessor, we
|
|
may be able to determine which of the outgoing edges will
|
|
be traversed. When this optimization applies, we are able
|
|
to avoid conditionals at runtime and we may expose secondary
|
|
optimization opportunities.
|
|
|
|
This routine is effectively a driver for the generic jump
|
|
threading code. It basically just presents the generic code
|
|
with edges that may be suitable for jump threading.
|
|
|
|
Unlike DOM, we do not iterate VRP if jump threading was successful.
|
|
While iterating may expose new opportunities for VRP, it is expected
|
|
those opportunities would be very limited and the compile time cost
|
|
to expose those opportunities would be significant.
|
|
|
|
As jump threading opportunities are discovered, they are registered
|
|
for later realization. */
|
|
|
|
static void
|
|
identify_jump_threads (void)
|
|
{
|
|
basic_block bb;
|
|
gimple dummy;
|
|
int i;
|
|
edge e;
|
|
|
|
/* Ugh. When substituting values earlier in this pass we can
|
|
wipe the dominance information. So rebuild the dominator
|
|
information as we need it within the jump threading code. */
|
|
calculate_dominance_info (CDI_DOMINATORS);
|
|
|
|
/* We do not allow VRP information to be used for jump threading
|
|
across a back edge in the CFG. Otherwise it becomes too
|
|
difficult to avoid eliminating loop exit tests. Of course
|
|
EDGE_DFS_BACK is not accurate at this time so we have to
|
|
recompute it. */
|
|
mark_dfs_back_edges ();
|
|
|
|
/* Do not thread across edges we are about to remove. Just marking
|
|
them as EDGE_DFS_BACK will do. */
|
|
FOR_EACH_VEC_ELT (to_remove_edges, i, e)
|
|
e->flags |= EDGE_DFS_BACK;
|
|
|
|
/* Allocate our unwinder stack to unwind any temporary equivalences
|
|
that might be recorded. */
|
|
equiv_stack.create (20);
|
|
|
|
/* To avoid lots of silly node creation, we create a single
|
|
conditional and just modify it in-place when attempting to
|
|
thread jumps. */
|
|
dummy = gimple_build_cond (EQ_EXPR,
|
|
integer_zero_node, integer_zero_node,
|
|
NULL, NULL);
|
|
|
|
/* Walk through all the blocks finding those which present a
|
|
potential jump threading opportunity. We could set this up
|
|
as a dominator walker and record data during the walk, but
|
|
I doubt it's worth the effort for the classes of jump
|
|
threading opportunities we are trying to identify at this
|
|
point in compilation. */
|
|
FOR_EACH_BB (bb)
|
|
{
|
|
gimple last;
|
|
|
|
/* If the generic jump threading code does not find this block
|
|
interesting, then there is nothing to do. */
|
|
if (! potentially_threadable_block (bb))
|
|
continue;
|
|
|
|
/* We only care about blocks ending in a COND_EXPR. While there
|
|
may be some value in handling SWITCH_EXPR here, I doubt it's
|
|
terribly important. */
|
|
last = gsi_stmt (gsi_last_bb (bb));
|
|
|
|
/* We're basically looking for a switch or any kind of conditional with
|
|
integral or pointer type arguments. Note the type of the second
|
|
argument will be the same as the first argument, so no need to
|
|
check it explicitly. */
|
|
if (gimple_code (last) == GIMPLE_SWITCH
|
|
|| (gimple_code (last) == GIMPLE_COND
|
|
&& TREE_CODE (gimple_cond_lhs (last)) == SSA_NAME
|
|
&& (INTEGRAL_TYPE_P (TREE_TYPE (gimple_cond_lhs (last)))
|
|
|| POINTER_TYPE_P (TREE_TYPE (gimple_cond_lhs (last))))
|
|
&& (TREE_CODE (gimple_cond_rhs (last)) == SSA_NAME
|
|
|| is_gimple_min_invariant (gimple_cond_rhs (last)))))
|
|
{
|
|
edge_iterator ei;
|
|
|
|
/* We've got a block with multiple predecessors and multiple
|
|
successors which also ends in a suitable conditional or
|
|
switch statement. For each predecessor, see if we can thread
|
|
it to a specific successor. */
|
|
FOR_EACH_EDGE (e, ei, bb->preds)
|
|
{
|
|
/* Do not thread across back edges or abnormal edges
|
|
in the CFG. */
|
|
if (e->flags & (EDGE_DFS_BACK | EDGE_COMPLEX))
|
|
continue;
|
|
|
|
thread_across_edge (dummy, e, true, &equiv_stack,
|
|
simplify_stmt_for_jump_threading);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* We do not actually update the CFG or SSA graphs at this point as
|
|
ASSERT_EXPRs are still in the IL and cfg cleanup code does not yet
|
|
handle ASSERT_EXPRs gracefully. */
|
|
}
|
|
|
|
/* We identified all the jump threading opportunities earlier, but could
|
|
not transform the CFG at that time. This routine transforms the
|
|
CFG and arranges for the dominator tree to be rebuilt if necessary.
|
|
|
|
Note the SSA graph update will occur during the normal TODO
|
|
processing by the pass manager. */
|
|
static void
|
|
finalize_jump_threads (void)
|
|
{
|
|
thread_through_all_blocks (false);
|
|
equiv_stack.release ();
|
|
}
|
|
|
|
|
|
/* Traverse all the blocks folding conditionals with known ranges. */
|
|
|
|
static void
|
|
vrp_finalize (void)
|
|
{
|
|
size_t i;
|
|
|
|
values_propagated = true;
|
|
|
|
if (dump_file)
|
|
{
|
|
fprintf (dump_file, "\nValue ranges after VRP:\n\n");
|
|
dump_all_value_ranges (dump_file);
|
|
fprintf (dump_file, "\n");
|
|
}
|
|
|
|
substitute_and_fold (op_with_constant_singleton_value_range,
|
|
vrp_fold_stmt, false);
|
|
|
|
if (warn_array_bounds)
|
|
check_all_array_refs ();
|
|
|
|
/* We must identify jump threading opportunities before we release
|
|
the datastructures built by VRP. */
|
|
identify_jump_threads ();
|
|
|
|
/* Free allocated memory. */
|
|
for (i = 0; i < num_vr_values; i++)
|
|
if (vr_value[i])
|
|
{
|
|
BITMAP_FREE (vr_value[i]->equiv);
|
|
free (vr_value[i]);
|
|
}
|
|
|
|
free (vr_value);
|
|
free (vr_phi_edge_counts);
|
|
|
|
/* So that we can distinguish between VRP data being available
|
|
and not available. */
|
|
vr_value = NULL;
|
|
vr_phi_edge_counts = NULL;
|
|
}
|
|
|
|
|
|
/* Main entry point to VRP (Value Range Propagation). This pass is
|
|
loosely based on J. R. C. Patterson, ``Accurate Static Branch
|
|
Prediction by Value Range Propagation,'' in SIGPLAN Conference on
|
|
Programming Language Design and Implementation, pp. 67-78, 1995.
|
|
Also available at http://citeseer.ist.psu.edu/patterson95accurate.html
|
|
|
|
This is essentially an SSA-CCP pass modified to deal with ranges
|
|
instead of constants.
|
|
|
|
While propagating ranges, we may find that two or more SSA name
|
|
have equivalent, though distinct ranges. For instance,
|
|
|
|
1 x_9 = p_3->a;
|
|
2 p_4 = ASSERT_EXPR <p_3, p_3 != 0>
|
|
3 if (p_4 == q_2)
|
|
4 p_5 = ASSERT_EXPR <p_4, p_4 == q_2>;
|
|
5 endif
|
|
6 if (q_2)
|
|
|
|
In the code above, pointer p_5 has range [q_2, q_2], but from the
|
|
code we can also determine that p_5 cannot be NULL and, if q_2 had
|
|
a non-varying range, p_5's range should also be compatible with it.
|
|
|
|
These equivalences are created by two expressions: ASSERT_EXPR and
|
|
copy operations. Since p_5 is an assertion on p_4, and p_4 was the
|
|
result of another assertion, then we can use the fact that p_5 and
|
|
p_4 are equivalent when evaluating p_5's range.
|
|
|
|
Together with value ranges, we also propagate these equivalences
|
|
between names so that we can take advantage of information from
|
|
multiple ranges when doing final replacement. Note that this
|
|
equivalency relation is transitive but not symmetric.
|
|
|
|
In the example above, p_5 is equivalent to p_4, q_2 and p_3, but we
|
|
cannot assert that q_2 is equivalent to p_5 because q_2 may be used
|
|
in contexts where that assertion does not hold (e.g., in line 6).
|
|
|
|
TODO, the main difference between this pass and Patterson's is that
|
|
we do not propagate edge probabilities. We only compute whether
|
|
edges can be taken or not. That is, instead of having a spectrum
|
|
of jump probabilities between 0 and 1, we only deal with 0, 1 and
|
|
DON'T KNOW. In the future, it may be worthwhile to propagate
|
|
probabilities to aid branch prediction. */
|
|
|
|
static unsigned int
|
|
execute_vrp (void)
|
|
{
|
|
int i;
|
|
edge e;
|
|
switch_update *su;
|
|
|
|
loop_optimizer_init (LOOPS_NORMAL | LOOPS_HAVE_RECORDED_EXITS);
|
|
rewrite_into_loop_closed_ssa (NULL, TODO_update_ssa);
|
|
scev_initialize ();
|
|
|
|
insert_range_assertions ();
|
|
|
|
to_remove_edges.create (10);
|
|
to_update_switch_stmts.create (5);
|
|
threadedge_initialize_values ();
|
|
|
|
vrp_initialize ();
|
|
ssa_propagate (vrp_visit_stmt, vrp_visit_phi_node);
|
|
vrp_finalize ();
|
|
|
|
free_numbers_of_iterations_estimates ();
|
|
|
|
/* ASSERT_EXPRs must be removed before finalizing jump threads
|
|
as finalizing jump threads calls the CFG cleanup code which
|
|
does not properly handle ASSERT_EXPRs. */
|
|
remove_range_assertions ();
|
|
|
|
/* If we exposed any new variables, go ahead and put them into
|
|
SSA form now, before we handle jump threading. This simplifies
|
|
interactions between rewriting of _DECL nodes into SSA form
|
|
and rewriting SSA_NAME nodes into SSA form after block
|
|
duplication and CFG manipulation. */
|
|
update_ssa (TODO_update_ssa);
|
|
|
|
finalize_jump_threads ();
|
|
|
|
/* Remove dead edges from SWITCH_EXPR optimization. This leaves the
|
|
CFG in a broken state and requires a cfg_cleanup run. */
|
|
FOR_EACH_VEC_ELT (to_remove_edges, i, e)
|
|
remove_edge (e);
|
|
/* Update SWITCH_EXPR case label vector. */
|
|
FOR_EACH_VEC_ELT (to_update_switch_stmts, i, su)
|
|
{
|
|
size_t j;
|
|
size_t n = TREE_VEC_LENGTH (su->vec);
|
|
tree label;
|
|
gimple_switch_set_num_labels (su->stmt, n);
|
|
for (j = 0; j < n; j++)
|
|
gimple_switch_set_label (su->stmt, j, TREE_VEC_ELT (su->vec, j));
|
|
/* As we may have replaced the default label with a regular one
|
|
make sure to make it a real default label again. This ensures
|
|
optimal expansion. */
|
|
label = gimple_switch_label (su->stmt, 0);
|
|
CASE_LOW (label) = NULL_TREE;
|
|
CASE_HIGH (label) = NULL_TREE;
|
|
}
|
|
|
|
if (to_remove_edges.length () > 0)
|
|
free_dominance_info (CDI_DOMINATORS);
|
|
|
|
to_remove_edges.release ();
|
|
to_update_switch_stmts.release ();
|
|
threadedge_finalize_values ();
|
|
|
|
scev_finalize ();
|
|
loop_optimizer_finalize ();
|
|
return 0;
|
|
}
|
|
|
|
static bool
|
|
gate_vrp (void)
|
|
{
|
|
return flag_tree_vrp != 0;
|
|
}
|
|
|
|
struct gimple_opt_pass pass_vrp =
|
|
{
|
|
{
|
|
GIMPLE_PASS,
|
|
"vrp", /* name */
|
|
OPTGROUP_NONE, /* optinfo_flags */
|
|
gate_vrp, /* gate */
|
|
execute_vrp, /* execute */
|
|
NULL, /* sub */
|
|
NULL, /* next */
|
|
0, /* static_pass_number */
|
|
TV_TREE_VRP, /* tv_id */
|
|
PROP_ssa, /* properties_required */
|
|
0, /* properties_provided */
|
|
0, /* properties_destroyed */
|
|
0, /* todo_flags_start */
|
|
TODO_cleanup_cfg
|
|
| TODO_update_ssa
|
|
| TODO_verify_ssa
|
|
| TODO_verify_flow
|
|
| TODO_ggc_collect /* todo_flags_finish */
|
|
}
|
|
};
|