public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
* [Bug target/101989] New: Fail to optimize (a & b) | (c & ~b) to vpternlog instruction.
@ 2021-08-20  1:46 crazylht at gmail dot com
  2021-08-20  1:50 ` [Bug target/101989] " crazylht at gmail dot com
                   ` (8 more replies)
  0 siblings, 9 replies; 10+ messages in thread
From: crazylht at gmail dot com @ 2021-08-20  1:46 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101989

            Bug ID: 101989
           Summary: Fail to optimize (a & b) | (c & ~b) to vpternlog
                    instruction.
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: crazylht at gmail dot com
  Target Milestone: ---
              Host: x86_64-pc-linux-gnu
            Target: x86_64-*-* i?86-*-*

cat test.c

__m128i foo (__m128i src1, __m128i src2, __m128i src3)
{
  return (src2 & ~src1) | (src3 & src1);
}

__m128i foo1 (__m128i src1, __m128i src2, __m128i src3)
{
  return (src2 & src1) | (src3 & ~src1);
}

gcc -O2 -march=cascadelake  generates

foo(long long __vector(2), long long __vector(2), long long __vector(2)):
        vpxor   %xmm2, %xmm1, %xmm2
        vpand   %xmm0, %xmm2, %xmm2
        vpxor   %xmm1, %xmm2, %xmm0
        ret
foo1(long long __vector(2), long long __vector(2), long long __vector(2)):
        vpxor   %xmm2, %xmm1, %xmm1
        vpand   %xmm0, %xmm1, %xmm1
        vpxor   %xmm2, %xmm1, %xmm0
        ret


icx generates

foo(long long __vector(2), long long __vector(2), long long __vector(2)):      
                 # 
        vpternlogq      xmm0, xmm2, xmm1, 202
        ret
foo1(long long __vector(2), long long __vector(2), long long __vector(2)):     
                 # 
        vpternlogq      xmm0, xmm1, xmm2, 202
        ret

Guess we need a post_reload splitter to match

Failed to match this instruction:
(set (reg:V2DI 88)
    (xor:V2DI (and:V2DI (xor:V2DI (reg:V2DI 92)
                (reg/v:V2DI 87 [ src3 ]))
            (reg:V2DI 91))
        (reg/v:V2DI 87 [ src3 ])))
Failed to match this instruction:

^ permalink raw reply	[flat|nested] 10+ messages in thread

end of thread, other threads:[~2022-09-25 19:35 UTC | newest]

Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-08-20  1:46 [Bug target/101989] New: Fail to optimize (a & b) | (c & ~b) to vpternlog instruction crazylht at gmail dot com
2021-08-20  1:50 ` [Bug target/101989] " crazylht at gmail dot com
2021-08-20  2:00 ` pinskia at gcc dot gnu.org
2021-08-24  9:45 ` cvs-commit at gcc dot gnu.org
2021-08-24 10:34 ` cvs-commit at gcc dot gnu.org
2021-08-24 10:35 ` crazylht at gmail dot com
2021-08-25  1:57 ` cvs-commit at gcc dot gnu.org
2021-08-25  2:32 ` pinskia at gcc dot gnu.org
2021-11-04  8:10 ` cvs-commit at gcc dot gnu.org
2022-09-25 19:35 ` ak at gcc dot gnu.org

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).