mirror/gcc
2
0
Fork 0
mirror of git://gcc.gnu.org/git/gcc.git synced 2025-04-20 02:00:48 +08:00
Code Issues Packages Projects Releases Wiki Activity

fold-const.c (fold_mathfn_compare): New function to simplify comparisons against built-in math functions.

Browse Source 
* fold-const.c (fold_mathfn_compare): New function to simplify
	comparisons against built-in math functions.  Fold comparisons
	of sqrt against constants.
	(fold): Call fold_mathfn_compare when appropriate.

	* gcc.dg/builtins-6.c: New test case.

From-SVN: r64619
This commit is contained in:
Roger Sayle 2003-03-20 17:48:26 +00:00
parent 952a6df761
commit c876997fea
4 changed files with 260 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

35
gcc/ChangeLog
View File

@ -1,3 +1,10 @@
2003-03-20 Roger Sayle <roger@eyesopen.com>
* fold-const.c (fold_mathfn_compare): New function to simplify
comparisons against built-in math functions. Fold comparisons
of sqrt against constants.
(fold): Call fold_mathfn_compare when appropriate.
2003-03-20 Richard Earnshaw <rearnsha@arm.com>
* ifcvt.c (find_if_case_1): If we add a new bb, update the dominance
@ -1542,24 +1549,24 @@ Sat Mar 8 14:13:35 CET 2003 Jan Hubicka <jh@suse.cz>
MEM, try loading the MEM into a register and taking the low-part
of that, to help CSE see the use of the MEM in its true mode.
2002-03-05 Tom Tromey <tromey@redhat.com>
2003-03-05 Tom Tromey <tromey@redhat.com>
* config/stormy16/stormy16.h (DWARF_LINE_MIN_INSTR_LENGTH):
Define.
2002-03-05 Nick Clifton <nickc@cambridge.redhat.com>
2003-03-05 Nick Clifton <nickc@cambridge.redhat.com>
* config/stormy16/stormy16.md ("*eqbranchsi"): Remove '+' on
operand 2.
("*ineqbranchsi"): Likewise.
2002-03-05 Andrew Haley <aph@cambridge.redhat.com>
2003-03-05 Andrew Haley <aph@cambridge.redhat.com>
* config/stormy16/stormy16.c (xstormy16_expand_prologue): Delete
mem_fake_push_rtx. Instead construct a SEQUENCE to show the
register store followed by a stack increment.
2002-03-05 Chris Moller <cmoller@redhat.com>
2003-03-05 Chris Moller <cmoller@redhat.com>
* config/stormy16/stormy16.c (REG_NEEDS_SAVE): added a term
to inhibit saving CARRY_REGS.
@ -2328,7 +2335,7 @@ Mon Mar 3 19:07:21 CET 2003 Jan Hubicka <jh@suse.cz>
(*tst_extzv_memqi_1_n): Likewise.
(a peephole2): New.
2002-02-28 Richard Sandiford <rsandifo@redhat.com>
2003-02-28 Richard Sandiford <rsandifo@redhat.com>
* config/mips/mips.h (CRT_CALL_STATIC_FUNCTION): Wrap in
#ifndef __mips16.
@ -4123,7 +4130,7 @@ Sun Feb 9 23:54:59 CET 2003 Jan Hubicka <jh@suse.cz>
simplify_binary_operation): Deal with vector modes
(simplify_ternary_operation): Deal with no-op VEC_MERGE.
2002-02-09 Richard Sandiford <rsandifo@redhat.com>
2003-02-09 Richard Sandiford <rsandifo@redhat.com>
* toplev.c (rest_of_compilation): Recompute register usage after
split_all_insns.
@ -4489,7 +4496,7 @@ Wed Feb 5 23:12:57 CET 2003 Jan Hubicka <jh@suse.cz>
* config/ia64/unwind-ia64.c: include coretypes.h, tm.h to get
config/ia64/linux.h
2002-02-05 Roger Sayle <roger@eyesopen.com>
2003-02-05 Roger Sayle <roger@eyesopen.com>
* cfgloop.h (flow_bb_inside_loop_p): Correct prototype again.
@ -4605,7 +4612,7 @@ Mon Feb 3 21:19:11 CET 2003 Jan Hubicka <jh@suse.cz>
(movups/movupd/movdqu patterns): Force one of operands to not be
memory.
2002-02-03 Roger Sayle <roger@eyesopen.com>
2003-02-03 Roger Sayle <roger@eyesopen.com>
* hooks.c (hook_rtx_rtx_identity): Generic hook function that
takes a single rtx and returns it unmodified.
@ -5624,11 +5631,11 @@ Sat Jan 25 21:04:33 CET 2003 Jan Hubicka <jh@suse.cz>
* config/h8300/h8300.c (h8300_shift_needs_scratch_p): Update a
comment.
2002-01-25 Richard Henderson <rth@redhat.com>
2003-01-25 Richard Henderson <rth@redhat.com>
* config/m68k/m68k-none.h (ASM_SPEC): Adjust inter-option spacing.
2002-01-25 Kelley Cook <kelleycook@comcast.net>
2003-01-25 Kelley Cook <kelleycook@comcast.net>
* ggc-simple.c (debug_ggc_tree): Add PTR cast.
@ -5646,7 +5653,7 @@ Sat Jan 25 21:04:33 CET 2003 Jan Hubicka <jh@suse.cz>
2002-02-19 Robert Lipe <robertlipe@usa.net>
* config/i386/t-sco5gas: (CRTSTUFF_T_CFLAGS_S): Delete -mcoff.
2002-01-25 Roger Sayle <roger@eyesopen.com>
2003-01-25 Roger Sayle <roger@eyesopen.com>
* builtins.c (purge_builtin_constant_p): Scan insn stream
sequentially rather than by basic block.
@ -5656,7 +5663,7 @@ Sat Jan 25 21:04:33 CET 2003 Jan Hubicka <jh@suse.cz>
* combine.c (simplify_comparison, case AND): Remove a redundant test.
2002-01-25 Roger Sayle <roger@eyesopen.com>
2003-01-25 Roger Sayle <roger@eyesopen.com>
* function.h (struct function): New field calls_constant_p.
(current_function_calls_constant_p): New macro for above.
@ -5668,7 +5675,7 @@ Sat Jan 25 21:04:33 CET 2003 Jan Hubicka <jh@suse.cz>
* integrate.c (expand_inline_function): Set calls_constant_p if
the function being inlined has calls_constant_p set.
2002-01-25 Roger Sayle <roger@eyesopen.com>
2003-01-25 Roger Sayle <roger@eyesopen.com>
* cse.c (fold_rtx): Instantiate CONSTANT_P_RTX to 0 when not
optimizing, even if flag_gcse is true.
@ -5728,7 +5735,7 @@ Sat Jan 25 11:10:03 CET 2003 Jan Hubicka <jh@suse.cz>
* builtins.c (fold_trunc_transparent_mathfn): Undo accidental commit.
2002-01-24 Stuart Hastings <stuart@apple.com>
2003-01-24 Stuart Hastings <stuart@apple.com>
* config/i386/i386.c (x86_output_mi_thunk): Add Darwin/x86 support.

155
gcc/fold-const.c
View File

@ -112,6 +112,8 @@ static int count_cond PARAMS ((tree, int));
static tree fold_binary_op_with_conditional_arg
PARAMS ((enum tree_code, tree, tree, tree, int));
static bool fold_real_zero_addition_p PARAMS ((tree, tree, int));
static tree fold_mathfn_compare PARAMS ((enum built_in_function,
enum tree_code, tree, tree, tree));
/* The following constants represent a bit based encoding of GCC's
comparison operators. This encoding simplifies transformations
@ -4661,6 +4663,144 @@ fold_real_zero_addition_p (type, addend, negate)
return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
}
/* Subroutine of fold() that checks comparisons of built-in math
functions against real constants.
FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
is the type of the result and ARG0 and ARG1 are the operands of the
comparison. ARG1 must be a TREE_REAL_CST.
The function returns the constant folded tree if a simplification
can be made, and NULL_TREE otherwise. */
static tree
fold_mathfn_compare (fcode, code, type, arg0, arg1)
enum built_in_function fcode;
enum tree_code code;
tree type, arg0, arg1;
{
REAL_VALUE_TYPE c;
if (fcode == BUILT_IN_SQRT
|| fcode == BUILT_IN_SQRTF
|| fcode == BUILT_IN_SQRTL)
{
tree arg = TREE_VALUE (TREE_OPERAND (arg0, 1));
enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg0));
c = TREE_REAL_CST (arg1);
if (REAL_VALUE_NEGATIVE (c))
{
/* sqrt(x) < y is always false, if y is negative. */
if (code == EQ_EXPR || code == LT_EXPR || code == LE_EXPR)
return omit_one_operand (type,
convert (type, integer_zero_node),
arg);
/* sqrt(x) > y is always true, if y is negative and we
don't care about NaNs, i.e. negative values of x. */
if (code == NE_EXPR || !HONOR_NANS (mode))
return omit_one_operand (type,
convert (type, integer_one_node),
arg);
/* sqrt(x) > y is the same as x >= 0, if y is negative. */
return fold (build (GE_EXPR, type, arg,
build_real (TREE_TYPE (arg), dconst0)));
}
else if (code == GT_EXPR || code == GE_EXPR)
{
REAL_VALUE_TYPE c2;
REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
real_convert (&c2, mode, &c2);
if (REAL_VALUE_ISINF (c2))
{
/* sqrt(x) > y is x == +Inf, when y is very large. */
if (HONOR_INFINITIES (mode))
return fold (build (EQ_EXPR, type, arg,
build_real (TREE_TYPE (arg), c2)));
/* sqrt(x) > y is always false, when y is very large
and we don't care about infinities. */
return omit_one_operand (type,
convert (type, integer_zero_node),
arg);
}
/* sqrt(x) > c is the same as x > c*c. */
return fold (build (code, type, arg,
build_real (TREE_TYPE (arg), c2)));
}
else if (code == LT_EXPR || code == LE_EXPR)
{
REAL_VALUE_TYPE c2;
REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
real_convert (&c2, mode, &c2);
if (REAL_VALUE_ISINF (c2))
{
/* sqrt(x) < y is always true, when y is a very large
value and we don't care about NaNs or Infinities. */
if (! HONOR_NANS (mode) && ! HONOR_INFINITIES (mode))
return omit_one_operand (type,
convert (type, integer_one_node),
arg);
/* sqrt(x) < y is x != +Inf when y is very large and we
don't care about NaNs. */
if (! HONOR_NANS (mode))
return fold (build (NE_EXPR, type, arg,
build_real (TREE_TYPE (arg), c2)));
/* sqrt(x) < y is x >= 0 when y is very large and we
don't care about Infinities. */
if (! HONOR_INFINITIES (mode))
return fold (build (GE_EXPR, type, arg,
build_real (TREE_TYPE (arg), dconst0)));
/* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
if ((*lang_hooks.decls.global_bindings_p) () != 0
|| contains_placeholder_p (arg))
return NULL_TREE;
arg = save_expr (arg);
return fold (build (TRUTH_ANDIF_EXPR, type,
fold (build (GE_EXPR, type, arg,
build_real (TREE_TYPE (arg),
dconst0))),
fold (build (NE_EXPR, type, arg,
build_real (TREE_TYPE (arg),
c2)))));
}
/* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
if (! HONOR_NANS (mode))
return fold (build (code, type, arg,
build_real (TREE_TYPE (arg), c2)));
/* sqrt(x) < c is the same as x >= 0 && x < c*c. */
if ((*lang_hooks.decls.global_bindings_p) () == 0
&& ! contains_placeholder_p (arg))
{
arg = save_expr (arg);
return fold (build (TRUTH_ANDIF_EXPR, type,
fold (build (GE_EXPR, type, arg,
build_real (TREE_TYPE (arg),
dconst0))),
fold (build (code, type, arg,
build_real (TREE_TYPE (arg),
c2)))));
}
}
}
return NULL_TREE;
}
/* Perform constant folding and related simplification of EXPR.
The related simplifications include x*1 => x, x*0 => 0, etc.,
@ -6209,6 +6349,21 @@ fold (expr)
arg1, TREE_OPERAND (arg0, 1), 0))
&& ! TREE_CONSTANT_OVERFLOW (tem))
return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
/* Fold comparisons against built-in math functions. */
if (TREE_CODE (arg1) == REAL_CST
&& flag_unsafe_math_optimizations
&& ! flag_errno_math)
{
enum built_in_function fcode = builtin_mathfn_code (arg0);
if (fcode != END_BUILTINS)
{
tem = fold_mathfn_compare (fcode, code, type, arg0, arg1);
if (tem != NULL_TREE)
return tem;
}
}
}
/* Convert foo++ == CONST into ++foo == CONST + INCR.

4
gcc/testsuite/ChangeLog
View File

@ -1,3 +1,7 @@
2003-03-20 Roger Sayle <roger@eyesopen.com>
* gcc.dg/builtins-6.c: New test case.
2003-03-19 Alan Modra <amodra@bigpond.net.au>
PR target/10073

80
gcc/testsuite/gcc.dg/builtins-6.c Normal file
View File

@ -0,0 +1,80 @@
/* Copyright (C) 2003 Free Software Foundation.
Verify that constant folding comparisons against built-in math functions
don't cause any problems for the compiler, and produce expected results.
Written by Roger Sayle, 15th March 2003. */
/* { dg-do run } */
/* { dg-options "-O2 -ffast-math" } */
#include <float.h>
extern void abort (void);
extern double sqrt (double);
int test1(double x)
{
return sqrt(x) < -9.0;
}
int test2(double x)
{
return sqrt(x) > -9.0;
}
int test3(double x)
{
return sqrt(x) < 9.0;
}
int test4(double x)
{
return sqrt(x) > 9.0;
}
int test5(double x)
{
return sqrt(x) < DBL_MAX;
}
int test6(double x)
{
return sqrt(x) > DBL_MAX;
}
int main()
{
double x;
x = 80.0;
if (test1 (x))
abort ();
if (! test2 (x))
abort ();
if (! test3 (x))
abort ();
if (test4 (x))
abort ();
if (! test5 (x))
abort ();
if (test6 (x))
abort ();
x = 100.0;
if (test1 (x))
abort ();
if (! test2 (x))
abort ();
if (test3 (x))
abort ();
if (! test4 (x))
abort ();
if (! test5 (x))
abort ();
if (test6 (x))
abort ();
return 0;
}