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tree.h (ALLOCA_FOR_VAR_P): Rename to CALL_ALLOCA_FOR_VAR_P.

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* tree.h (ALLOCA_FOR_VAR_P): Rename to CALL_ALLOCA_FOR_VAR_P.
	* builtins.c (expand_builtin): Use CALL_ALLOCA_FOR_VAR_P.
	* function.c (gimplify_parameters): Ditto.
	* gimplify.c (gimplify_vla_decl): Ditto.

	* gimple.h (enum gf_mask): Add GF_CALL_ALLOCA_FOR_VAR.
	(gimple_call_set_alloca_for_var): New inline function.
	(gimple_call_alloca_for_var_p): Ditto.
	* gimple.c (gimple_build_call_from_tree): Remember CALL_ALLOCA_FOR_VAR_P
	state.
	* cfgexpand.c (expand_call_stmt): Restore CALL_ALLOCA_FOR_VAR_P state.

	* tree-inline.c (inline_forbidden_p_stmt): Don't reject alloca
	calls if they were for VLA objects.

From-SVN: r172516
This commit is contained in:
Michael Matz 2011-04-15 19:48:25 +00:00 committed by Michael Matz
parent dee74c3436
commit 63d2a3533f
9 changed files with 63 additions and 8 deletions
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17
gcc/ChangeLog
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@ -1,3 +1,20 @@
2011-04-15 Michael Matz <matz@suse.de>
* tree.h (ALLOCA_FOR_VAR_P): Rename to CALL_ALLOCA_FOR_VAR_P.
* builtins.c (expand_builtin): Use CALL_ALLOCA_FOR_VAR_P.
* function.c (gimplify_parameters): Ditto.
* gimplify.c (gimplify_vla_decl): Ditto.
* gimple.h (enum gf_mask): Add GF_CALL_ALLOCA_FOR_VAR.
(gimple_call_set_alloca_for_var): New inline function.
(gimple_call_alloca_for_var_p): Ditto.
* gimple.c (gimple_build_call_from_tree): Remember CALL_ALLOCA_FOR_VAR_P
state.
* cfgexpand.c (expand_call_stmt): Restore CALL_ALLOCA_FOR_VAR_P state.
* tree-inline.c (inline_forbidden_p_stmt): Don't reject alloca
calls if they were for VLA objects.
2011-04-15 Martin Jambor <mjambor@suse.cz>
* ipa-prop.c (ipa_analyze_virtual_call_uses): Remove handling

2
gcc/builtins.c
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@ -6025,7 +6025,7 @@ expand_builtin (tree exp, rtx target, rtx subtarget, enum machine_mode mode,
case BUILT_IN_ALLOCA:
/* If the allocation stems from the declaration of a variable-sized
object, it cannot accumulate. */
target = expand_builtin_alloca (exp, ALLOCA_FOR_VAR_P (exp));
target = expand_builtin_alloca (exp, CALL_ALLOCA_FOR_VAR_P (exp));
if (target)
return target;
break;

7
gcc/cfgexpand.c
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@ -1879,7 +1879,12 @@ expand_call_stmt (gimple stmt)
CALL_EXPR_TAILCALL (exp) = gimple_call_tail_p (stmt);
CALL_EXPR_RETURN_SLOT_OPT (exp) = gimple_call_return_slot_opt_p (stmt);
CALL_FROM_THUNK_P (exp) = gimple_call_from_thunk_p (stmt);
if (decl
&& DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL
&& DECL_FUNCTION_CODE (decl) == BUILT_IN_ALLOCA)
CALL_ALLOCA_FOR_VAR_P (exp) = gimple_call_alloca_for_var_p (stmt);
else
CALL_FROM_THUNK_P (exp) = gimple_call_from_thunk_p (stmt);
CALL_CANNOT_INLINE_P (exp) = gimple_call_cannot_inline_p (stmt);
CALL_EXPR_VA_ARG_PACK (exp) = gimple_call_va_arg_pack_p (stmt);
SET_EXPR_LOCATION (exp, gimple_location (stmt));

2
gcc/function.c
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@ -3652,7 +3652,7 @@ gimplify_parameters (void)
t = built_in_decls[BUILT_IN_ALLOCA];
t = build_call_expr (t, 1, DECL_SIZE_UNIT (parm));
/* The call has been built for a variable-sized object. */
ALLOCA_FOR_VAR_P (t) = 1;
CALL_ALLOCA_FOR_VAR_P (t) = 1;
t = fold_convert (ptr_type, t);
t = build2 (MODIFY_EXPR, TREE_TYPE (addr), addr, t);
gimplify_and_add (t, &stmts);

7
gcc/gimple.c
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@ -303,7 +303,12 @@ gimple_build_call_from_tree (tree t)
gimple_call_set_tail (call, CALL_EXPR_TAILCALL (t));
gimple_call_set_cannot_inline (call, CALL_CANNOT_INLINE_P (t));
gimple_call_set_return_slot_opt (call, CALL_EXPR_RETURN_SLOT_OPT (t));
gimple_call_set_from_thunk (call, CALL_FROM_THUNK_P (t));
if (fndecl
&& DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
&& DECL_FUNCTION_CODE (fndecl) == BUILT_IN_ALLOCA)
gimple_call_set_alloca_for_var (call, CALL_ALLOCA_FOR_VAR_P (t));
else
gimple_call_set_from_thunk (call, CALL_FROM_THUNK_P (t));
gimple_call_set_va_arg_pack (call, CALL_EXPR_VA_ARG_PACK (t));
gimple_call_set_nothrow (call, TREE_NOTHROW (t));
gimple_set_no_warning (call, TREE_NO_WARNING (t));

24
gcc/gimple.h
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@ -102,6 +102,7 @@ enum gf_mask {
GF_CALL_TAILCALL = 1 << 3,
GF_CALL_VA_ARG_PACK = 1 << 4,
GF_CALL_NOTHROW = 1 << 5,
GF_CALL_ALLOCA_FOR_VAR = 1 << 6,
GF_OMP_PARALLEL_COMBINED = 1 << 0,
/* True on an GIMPLE_OMP_RETURN statement if the return does not require
@ -2330,6 +2331,29 @@ gimple_call_nothrow_p (gimple s)
return (gimple_call_flags (s) & ECF_NOTHROW) != 0;
}
/* If FOR_VAR is true, GIMPLE_CALL S is a call to builtin_alloca that
is known to be emitted for VLA objects. Those are wrapped by
stack_save/stack_restore calls and hence can't lead to unbounded
stack growth even when they occur in loops. */
static inline void
gimple_call_set_alloca_for_var (gimple s, bool for_var)
{
GIMPLE_CHECK (s, GIMPLE_CALL);
if (for_var)
s->gsbase.subcode |= GF_CALL_ALLOCA_FOR_VAR;
else
s->gsbase.subcode &= ~GF_CALL_ALLOCA_FOR_VAR;
}
/* Return true of S is a call to builtin_alloca emitted for VLA objects. */
static inline bool
gimple_call_alloca_for_var_p (gimple s)
{
GIMPLE_CHECK (s, GIMPLE_CALL);
return (s->gsbase.subcode & GF_CALL_ALLOCA_FOR_VAR) != 0;
}
/* Copy all the GF_CALL_* flags from ORIG_CALL to DEST_CALL. */

2
gcc/gimplify.c
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@ -1337,7 +1337,7 @@ gimplify_vla_decl (tree decl, gimple_seq *seq_p)
t = built_in_decls[BUILT_IN_ALLOCA];
t = build_call_expr (t, 1, DECL_SIZE_UNIT (decl));
/* The call has been built for a variable-sized object. */
ALLOCA_FOR_VAR_P (t) = 1;
CALL_ALLOCA_FOR_VAR_P (t) = 1;
t = fold_convert (ptr_type, t);
t = build2 (MODIFY_EXPR, TREE_TYPE (addr), addr, t);

5
gcc/tree-inline.c
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@ -2997,8 +2997,11 @@ inline_forbidden_p_stmt (gimple_stmt_iterator *gsi, bool *handled_ops_p,
this may change program's memory overhead drastically when the
function using alloca is called in loop. In GCC present in
SPEC2000 inlining into schedule_block cause it to require 2GB of
RAM instead of 256MB. */
RAM instead of 256MB. Don't do so for alloca calls emitted for
VLA objects as those can't cause unbounded growth (they're always
wrapped inside stack_save/stack_restore regions. */
if (gimple_alloca_call_p (stmt)
&& !gimple_call_alloca_for_var_p (stmt)
&& !lookup_attribute ("always_inline", DECL_ATTRIBUTES (fn)))
{
inline_forbidden_reason

5
gcc/tree.h
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@ -574,7 +574,7 @@ struct GTY(()) tree_common {
all decls
CALL_FROM_THUNK_P and
ALLOCA_FOR_VAR_P in
CALL_ALLOCA_FOR_VAR_P in
CALL_EXPR
side_effects_flag:
@ -1388,7 +1388,8 @@ extern void omp_clause_range_check_failed (const_tree, const char *, int,
/* In a CALL_EXPR, if the function being called is BUILT_IN_ALLOCA, means that
it has been built for the declaration of a variable-sized object. */
#define ALLOCA_FOR_VAR_P(NODE) (CALL_EXPR_CHECK (NODE)->base.protected_flag)
#define CALL_ALLOCA_FOR_VAR_P(NODE) \
(CALL_EXPR_CHECK (NODE)->base.protected_flag)
/* In a type, nonzero means that all objects of the type are guaranteed by the
language or front-end to be properly aligned, so we can indicate that a MEM