[Bug target/53759] New: gcc -mavx emits vshufps for__builtin_ia32_loadlps

[Bug target/53759] New: gcc -mavx emits vshufps for__builtin_ia32_loadlps

[dag at nimrod dot no]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53759

             Bug #: 53759
           Summary: gcc -mavx emits vshufps for__builtin_ia32_loadlps
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: dag@nimrod.no

[Bug target/53759] gcc -mavx emits vshufps for__builtin_ia32_loadlps

[dag at nimrod dot no]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53759

--- Comment #1 from Dag Lem <dag at nimrod dot no> 2012-06-24 12:45:55 UTC ---
Test code as follows:
------------------------
typedef float v4sf __attribute__ ((vector_size (4*4)));
typedef float v2sf __attribute__ ((vector_size (4*2)));

v2sf mem[1];

int main()
{
  v4sf reg = (v4sf){0,0,0,0};
  reg = __builtin_ia32_loadlps(reg, mem);
  return reg[0];
}
------------------------

With -msse, gcc emits the following code:

    xorps    %xmm0, %xmm0
    movlps    mem, %xmm0

However with -mavx, gcc emits:

    vxorps    %xmm0, %xmm0, %xmm0
    vmovlps    mem, %xmm1, %xmm1
    vshufps    $0xe4, %xmm0, %xmm1, %xmm0

Shouldn't this rather have been something like

    vxorps    %xmm0, %xmm0, %xmm0
    vmovlps    mem, %xmm0, %xmm0

???

[Bug target/53759] [4.7/4.8 Regression] gcc -mavx emits vshufps for __builtin_ia32_loadlps

[hjl.tools at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53759

H.J. Lu <hjl.tools at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2012-06-24
                 CC|                            |areg.melikadamyan at gmail
                   |                            |dot com, hjl.tools at gmail
                   |                            |dot com, ubizjak at gmail
                   |                            |dot com
   Target Milestone|---                         |4.7.2
            Summary|gcc -mavx emits vshufps for |[4.7/4.8 Regression] gcc
                   |__builtin_ia32_loadlps      |-mavx emits vshufps for
                   |                            |__builtin_ia32_loadlps
     Ever Confirmed|0                           |1

--- Comment #2 from H.J. Lu <hjl.tools at gmail dot com> 2012-06-24 14:54:44 UTC ---
GCC 4.6 doesn't have this problem:

[hjl@gnu-6 pr53759]$ cat x.i
typedef float v4sf __attribute__ ((vector_size (4*4)));
typedef float v2sf __attribute__ ((vector_size (4*2)));

v2sf mem[1];

int main()
{
  v4sf reg = (v4sf){0,0,0,0};
  reg = __builtin_ia32_loadlps(reg, mem);
  return reg[0];
}
[hjl@gnu-6 pr53759]$ gcc -S -mavx -O x.i
[hjl@gnu-6 pr53759]$ cat x.s
    .file    "x.i"
    .text
    .globl    main
    .type    main, @function
main:
.LFB0:
    .cfi_startproc
    vxorps    %xmm0, %xmm0, %xmm0
    vmovlps    mem(%rip), %xmm0, %xmm0
    vcvttss2si    %xmm0, %eax
    ret
    .cfi_endproc
.LFE0:
    .size    main, .-main
    .comm    mem,8,8
    .ident    "GCC: (GNU) 4.6.3 20120306 (Red Hat 4.6.3-2)"
    .section    .note.GNU-stack,"",@progbits
[hjl@gnu-6 pr53759]$

[Bug target/53759] [4.7/4.8 Regression] gcc -mavx emits vshufps for __builtin_ia32_loadlps

[hjl.tools at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53759

--- Comment #3 from H.J. Lu <hjl.tools at gmail dot com> 2012-06-24 15:46:33 UTC ---
It is caused by revision 172123:

http://gcc.gnu.org/ml/gcc-cvs/2011-04/msg00316.html

[Bug target/53759] [4.7/4.8 Regression] gcc -mavx emits vshufps for __builtin_ia32_loadlps

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53759

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
                 CC|                            |jakub at gcc dot gnu.org
         AssignedTo|unassigned at gcc dot       |jakub at gcc dot gnu.org
                   |gnu.org                     |

[Bug target/53759] [4.7/4.8 Regression] gcc -mavx emits vshufps for __builtin_ia32_loadlps

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53759

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-06-25 08:48:50 UTC ---
Created attachment 27699
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=27699
gcc48-pr53759.patch

Sounds like an obvious typo in that change, the x, x, x alternative is already
earlier and shouldn't use vmovlps insn, so that obviously should have been x,
m, x.

[Bug target/53759] [4.7/4.8 Regression] gcc -mavx emits vshufps for __builtin_ia32_loadlps

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53759

--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-06-25 14:53:04 UTC ---
Author: jakub
Date: Mon Jun 25 14:52:59 2012
New Revision: 188937

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=188937
Log:
    PR target/53759
    * config/i386/sse.md (sse_loadlps): Use x m x constraints instead
    of x x x in the vmovlps load alternative.

    * gcc.target/i386/pr53759.c: New test.

Added:
    trunk/gcc/testsuite/gcc.target/i386/pr53759.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/config/i386/sse.md
    trunk/gcc/testsuite/ChangeLog

[Bug target/53759] [4.7/4.8 Regression] gcc -mavx emits vshufps for __builtin_ia32_loadlps

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53759

--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-06-25 14:56:22 UTC ---
Author: jakub
Date: Mon Jun 25 14:56:17 2012
New Revision: 188938

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=188938
Log:
    PR target/53759
    * config/i386/sse.md (sse_loadlps): Use x m x constraints instead
    of x x x in the vmovlps load alternative.

    * gcc.target/i386/pr53759.c: New test.

Added:
    branches/gcc-4_7-branch/gcc/testsuite/gcc.target/i386/pr53759.c
Modified:
    branches/gcc-4_7-branch/gcc/ChangeLog
    branches/gcc-4_7-branch/gcc/config/i386/sse.md
    branches/gcc-4_7-branch/gcc/testsuite/ChangeLog

[Bug target/53759] [4.7/4.8 Regression] gcc -mavx emits vshufps for __builtin_ia32_loadlps

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53759

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

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

--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-06-25 15:05:09 UTC ---
Should be fixed now, thanks.