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* [Bug target/52568] New: suboptimal __builtin_shuffle on cycles with AVX
@ 2012-03-12 19:00 marc.glisse at normalesup dot org
2012-03-13 8:36 ` [Bug target/52568] " jakub at gcc dot gnu.org
` (4 more replies)
0 siblings, 5 replies; 6+ messages in thread
From: marc.glisse at normalesup dot org @ 2012-03-12 19:00 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52568
Bug #: 52568
Summary: suboptimal __builtin_shuffle on cycles with AVX
Classification: Unclassified
Product: gcc
Version: 4.7.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
AssignedTo: unassigned@gcc.gnu.org
ReportedBy: marc.glisse@normalesup.org
Hello,
I compiled the following with -O3 (or -Os) and -mavx
#include <x86intrin.h>
__m256d left(__m256d x){
__m256i mask={1,2,3,0};
return __builtin_shuffle(x,mask);
}
(by the way, for some reason, gcc insists that 'mask' is set but not used with
-Wall)
and got:
vunpckhpd %xmm0, %xmm0, %xmm3
vmovapd %xmm0, %xmm1
vextractf128 $0x1, %ymm0, %xmm0
vmovaps %xmm0, %xmm2
vunpckhpd %xmm0, %xmm0, %xmm0
vunpcklpd %xmm1, %xmm0, %xmm1
vunpcklpd %xmm2, %xmm3, %xmm0
vinsertf128 $0x1, %xmm1, %ymm0, %ymm0
ret
That doesn't really match the code I currently use to do this:
#ifdef __AVX2__
__m256d d=_mm256_permute4x64_pd(x,1+2*4+3*16+0*64);
#else
__m256d b=_mm256_shuffle_pd(x,x,5);
__m256d c=_mm256_permute2f128_pd(b,b,1);
__m256d d=_mm256_blend_pd(b,c,10);
#endif
Could something recognizing this permutation pattern (and the right cyclic
shift) be added? I know there are too many shuffles to hand-code them all, but
cycles seem like they shouldn't be too uncommon.
With -mavx2, I get a single vpermq, which is close enough to the expected
vpermpd.
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug target/52568] suboptimal __builtin_shuffle on cycles with AVX
2012-03-12 19:00 [Bug target/52568] New: suboptimal __builtin_shuffle on cycles with AVX marc.glisse at normalesup dot org
@ 2012-03-13 8:36 ` jakub at gcc dot gnu.org
2012-03-13 8:44 ` rguenth at gcc dot gnu.org
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: jakub at gcc dot gnu.org @ 2012-03-13 8:36 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52568
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |jakub at gcc dot gnu.org
--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-03-13 08:36:29 UTC ---
-Wunused-but-set-* warning false positive tracked in PR52577.
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug target/52568] suboptimal __builtin_shuffle on cycles with AVX
2012-03-12 19:00 [Bug target/52568] New: suboptimal __builtin_shuffle on cycles with AVX marc.glisse at normalesup dot org
2012-03-13 8:36 ` [Bug target/52568] " jakub at gcc dot gnu.org
@ 2012-03-13 8:44 ` rguenth at gcc dot gnu.org
2012-03-15 23:47 ` jakub at gcc dot gnu.org
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: rguenth at gcc dot gnu.org @ 2012-03-13 8:44 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52568
Richard Guenther <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |missed-optimization
Target| |x86_64-*-*
Status|UNCONFIRMED |NEW
Last reconfirmed| |2012-03-13
Ever Confirmed|0 |1
--- Comment #2 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-03-13 08:44:06 UTC ---
Confirmed.
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug target/52568] suboptimal __builtin_shuffle on cycles with AVX
2012-03-12 19:00 [Bug target/52568] New: suboptimal __builtin_shuffle on cycles with AVX marc.glisse at normalesup dot org
2012-03-13 8:36 ` [Bug target/52568] " jakub at gcc dot gnu.org
2012-03-13 8:44 ` rguenth at gcc dot gnu.org
@ 2012-03-15 23:47 ` jakub at gcc dot gnu.org
2012-03-15 23:54 ` jakub at gcc dot gnu.org
2012-03-16 8:28 ` jakub at gcc dot gnu.org
4 siblings, 0 replies; 6+ messages in thread
From: jakub at gcc dot gnu.org @ 2012-03-15 23:47 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52568
--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-03-15 23:45:49 UTC ---
Author: jakub
Date: Thu Mar 15 23:45:45 2012
New Revision: 185446
URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=185446
Log:
PR target/52568
* config/i386/sse.md (UNSPEC_VPERMDF): Remove.
(avx2_permv4df): Remove.
(avx2_permv4di): Macroize into...
(avx2_perm<mode>): ... this using VI8F_256 iterator.
(avx2_permv4di_1): Macroize into...
(avx2_perm<mode>_1): ... this using VI8F_256 iterator.
Modified:
trunk/gcc/ChangeLog
trunk/gcc/config/i386/sse.md
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug target/52568] suboptimal __builtin_shuffle on cycles with AVX
2012-03-12 19:00 [Bug target/52568] New: suboptimal __builtin_shuffle on cycles with AVX marc.glisse at normalesup dot org
` (2 preceding siblings ...)
2012-03-15 23:47 ` jakub at gcc dot gnu.org
@ 2012-03-15 23:54 ` jakub at gcc dot gnu.org
2012-03-16 8:28 ` jakub at gcc dot gnu.org
4 siblings, 0 replies; 6+ messages in thread
From: jakub at gcc dot gnu.org @ 2012-03-15 23:54 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52568
--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-03-15 23:46:37 UTC ---
Author: jakub
Date: Thu Mar 15 23:46:34 2012
New Revision: 185447
URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=185447
Log:
PR target/52568
* config/i386/i386.c (expand_vec_perm_vperm2f128_vblend): New
function.
(ix86_expand_vec_perm_const_1): Use it.
* gcc.dg/torture/vshuf-4.inc: Add two new tests.
* gcc.dg/torture/vshuf-8.inc: Likewise.
* gcc.dg/torture/vshuf-16.inc: Likewise.
* gcc.dg/torture/vshuf-32.inc: Likewise.
Modified:
trunk/gcc/ChangeLog
trunk/gcc/config/i386/i386.c
trunk/gcc/testsuite/ChangeLog
trunk/gcc/testsuite/gcc.dg/torture/vshuf-16.inc
trunk/gcc/testsuite/gcc.dg/torture/vshuf-32.inc
trunk/gcc/testsuite/gcc.dg/torture/vshuf-4.inc
trunk/gcc/testsuite/gcc.dg/torture/vshuf-8.inc
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug target/52568] suboptimal __builtin_shuffle on cycles with AVX
2012-03-12 19:00 [Bug target/52568] New: suboptimal __builtin_shuffle on cycles with AVX marc.glisse at normalesup dot org
` (3 preceding siblings ...)
2012-03-15 23:54 ` jakub at gcc dot gnu.org
@ 2012-03-16 8:28 ` jakub at gcc dot gnu.org
4 siblings, 0 replies; 6+ messages in thread
From: jakub at gcc dot gnu.org @ 2012-03-16 8:28 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52568
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |RESOLVED
Resolution| |FIXED
--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-03-16 07:40:13 UTC ---
Should be fixed on the trunk. For -mavx2 we now generate vpermpd, for -mavx
vpermilpd + vperm2f128 + vblendpd.
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2012-03-16 7:40 UTC | newest]
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2012-03-12 19:00 [Bug target/52568] New: suboptimal __builtin_shuffle on cycles with AVX marc.glisse at normalesup dot org
2012-03-13 8:36 ` [Bug target/52568] " jakub at gcc dot gnu.org
2012-03-13 8:44 ` rguenth at gcc dot gnu.org
2012-03-15 23:47 ` jakub at gcc dot gnu.org
2012-03-15 23:54 ` jakub at gcc dot gnu.org
2012-03-16 8:28 ` jakub at gcc dot gnu.org
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