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* [Bug tree-optimization/56790] New: VEC_COND_EXPR not constant folded
@ 2013-03-30 23:03 glisse at gcc dot gnu.org
2013-04-02 9:10 ` [Bug tree-optimization/56790] " rguenth at gcc dot gnu.org
2013-04-12 14:02 ` glisse at gcc dot gnu.org
0 siblings, 2 replies; 3+ messages in thread
From: glisse at gcc dot gnu.org @ 2013-03-30 23:03 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56790
Bug #: 56790
Summary: VEC_COND_EXPR not constant folded
Classification: Unclassified
Product: gcc
Version: 4.8.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: enhancement
Priority: P3
Component: tree-optimization
AssignedTo: unassigned@gcc.gnu.org
ReportedBy: glisse@gcc.gnu.org
Target: x86_64-linux-gnu
#include <x86intrin.h>
__m128d f(){
__m128d a={5,7};
__m128d b={11,13};
__m128i m={-1,0};
return m?a:b;
}
With -msse3 or less, this is lowered to scalar operations and thus to a
constant. However, with -msse4 or higher, nothing folds it to a constant,
either at tree level or rtl level, and we end up with:
pxor %xmm0, %xmm0
pcmpgtq .LC0(%rip), %xmm0
movapd .LC2(%rip), %xmm1
blendvpd %xmm0, .LC1(%rip), %xmm1
movapd %xmm1, %xmm0
The most natural seems to be to add something to fold-const.c, which currently
only handles the case where the first argument is all 1s or all 0s. It would be
good if the optimization worked when the second and third arguments can be
either VECTOR_CST or CONSTRUCTOR, similarly to VEC_PERM_EXPR.
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug tree-optimization/56790] VEC_COND_EXPR not constant folded
2013-03-30 23:03 [Bug tree-optimization/56790] New: VEC_COND_EXPR not constant folded glisse at gcc dot gnu.org
@ 2013-04-02 9:10 ` rguenth at gcc dot gnu.org
2013-04-12 14:02 ` glisse at gcc dot gnu.org
1 sibling, 0 replies; 3+ messages in thread
From: rguenth at gcc dot gnu.org @ 2013-04-02 9:10 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56790
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Last reconfirmed| |2013-04-02
Ever Confirmed|0 |1
--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> 2013-04-02 09:10:14 UTC ---
Confirmed.
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug tree-optimization/56790] VEC_COND_EXPR not constant folded
2013-03-30 23:03 [Bug tree-optimization/56790] New: VEC_COND_EXPR not constant folded glisse at gcc dot gnu.org
2013-04-02 9:10 ` [Bug tree-optimization/56790] " rguenth at gcc dot gnu.org
@ 2013-04-12 14:02 ` glisse at gcc dot gnu.org
1 sibling, 0 replies; 3+ messages in thread
From: glisse at gcc dot gnu.org @ 2013-04-12 14:02 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56790
Marc Glisse <glisse at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |RESOLVED
Resolution| |FIXED
--- Comment #2 from Marc Glisse <glisse at gcc dot gnu.org> 2013-04-12 14:02:17 UTC ---
r197395 | glisse | 2013-04-03 11:49:44 +0200 (Wed, 03 Apr 2013) | 10 lines
2013-04-03 Marc Glisse <marc.glisse@inria.fr>
PR tree-optimization/56790
gcc/
* fold-const.c (fold_ternary_loc) <VEC_COND_EXPR>: Add constant
folding.
gcc/testsuite/
* g++.dg/ext/pr56790-1.C: New testcase.
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2013-04-12 14:02 UTC | newest]
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2013-03-30 23:03 [Bug tree-optimization/56790] New: VEC_COND_EXPR not constant folded glisse at gcc dot gnu.org
2013-04-02 9:10 ` [Bug tree-optimization/56790] " rguenth at gcc dot gnu.org
2013-04-12 14:02 ` glisse at gcc dot gnu.org
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