[Bug target/113090] New: Suboptimal vector permuation for 64-bit vector.

[Bug target/113090] New: Suboptimal vector permuation for 64-bit vector.

[liuhongt at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113090

            Bug ID: 113090
           Summary: Suboptimal vector permuation for 64-bit vector.
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: liuhongt at gcc dot gnu.org
  Target Milestone: ---

When working on PR113079, loop vectorizer try to reduc sum of v2si with
permuation, x86 backend generates

typedef int v2si __attribute__((vector_size(8)));

v2si
foo (v2si a, v2si b)
{
    return __builtin_shufflevector (a, b, 1, 2);
}

foo(int __vector(2), int __vector(2)):
        vpshufb xmm0, xmm0, XMMWORD PTR .LC0[rip]
        vpshufb xmm1, xmm1, XMMWORD PTR .LC1[rip]
        vpor    xmm0, xmm0, xmm1

But it can be better with

        .cfi_startproc
        punpcklqdq      %xmm1, %xmm0
        pshufd  $153, %xmm0, %xmm0
        ret

[Bug target/113090] Suboptimal vector permuation for 64-bit vector.

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113090

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2023-12-20
             Status|UNCONFIRMED                 |NEW

[Bug target/113090] Suboptimal vector permuation for 64-bit vector.

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113090

--- Comment #1 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by hongtao Liu <liuhongt@gcc.gnu.org>:

https://gcc.gnu.org/g:a9f642783853b60bb0a59562b8ab3ed10ec01641

commit r15-234-ga9f642783853b60bb0a59562b8ab3ed10ec01641
Author: liuhongt <hongtao.liu@intel.com>
Date:   Wed Dec 20 11:54:43 2023 +0800

    Optimize 64-bit vector permutation with punpcklqdq + 128-bit vector pshuf.

    gcc/ChangeLog:

            PR target/113090
            * config/i386/i386-expand.cc
            (expand_vec_perm_punpckldq_pshuf): New function.
            (ix86_expand_vec_perm_const_1): Try
            expand_vec_perm_punpckldq_pshuf for sequence of 2
            instructions.

    gcc/testsuite/ChangeLog:

            * gcc.target/i386/pr113090.c: New test.

[Bug target/113090] Suboptimal vector permuation for 64-bit vector.

[liuhongt at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113090

Hongtao Liu <liuhongt at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |FIXED
             Status|NEW                         |RESOLVED

--- Comment #2 from Hongtao Liu <liuhongt at gcc dot gnu.org> ---
Fixed in GCC15