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re PR middle-end/40106 (Weird interaction between optimize_insn_for_speed_p and -funsafe-math-optimizations)

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2010-03-22  Richard Guenther  <rguenther@suse.de>

	PR middle-end/40106
	* builtins.c (expand_builtin_pow): Expand pow (x, 1.5) as
	x * sqrt (x) even when optimizing for size if the target
	has native support for sqrt.

From-SVN: r157623
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Richard Guenther 2010-03-22 12:38:02 +00:00 committed by Richard Biener
parent 2305a1e82e
commit 6af84c851d
2 changed files with 15 additions and 2 deletions
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7
gcc/ChangeLog
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@ -1,3 +1,10 @@
2010-03-22 Richard Guenther <rguenther@suse.de>
PR middle-end/40106
* builtins.c (expand_builtin_pow): Expand pow (x, 1.5) as
x * sqrt (x) even when optimizing for size if the target
has native support for sqrt.
2010-03-22 Jakub Jelinek <jakub@redhat.com>
* varasm.c (make_decl_rtl_for_debug): Also clear

10
gcc/builtins.c
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@ -2984,10 +2984,16 @@ expand_builtin_pow (tree exp, rtx target, rtx subtarget)
&& ((flag_unsafe_math_optimizations
&& optimize_insn_for_speed_p ()
&& powi_cost (n/2) <= POWI_MAX_MULTS)
/* Even the c==0.5 case cannot be done unconditionally
/* Even the c == 0.5 case cannot be done unconditionally
when we need to preserve signed zeros, as
pow (-0, 0.5) is +0, while sqrt(-0) is -0. */
|| (!HONOR_SIGNED_ZEROS (mode) && n == 1)))
|| (!HONOR_SIGNED_ZEROS (mode) && n == 1)
/* For c == 1.5 we can assume that x * sqrt (x) is always
smaller than pow (x, 1.5) if sqrt will not be expanded
as a call. */
|| (n == 3
&& (optab_handler (sqrt_optab, mode)->insn_code
!= CODE_FOR_nothing))))
{
tree call_expr = build_call_nofold (fn, 1, narg0);
/* Use expand_expr in case the newly built call expression