[Bug target/67849] New: AVX512 Hitting upper-bank register on extract insn split

[Bug target/67849] New: AVX512 Hitting upper-bank register on extract insn split

[afomin.mailbox at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67849

            Bug ID: 67849
           Summary: AVX512 Hitting upper-bank register on extract insn
                    split
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Keywords: assemble-failure, wrong-code
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: afomin.mailbox at gmail dot com
                CC: kyukhin at gcc dot gnu.org
  Target Milestone: ---
            Target: i?86-*-*, x86_64-*-*

This issue has been found while compiling SPEC2006 CPU 447.dealII benchmark for
KNL architecture.

Given a machine that does not have AVX512VL extension, following "else" branch
for vec_extract_lo insn described below ...

(define_insn "vec_extract_lo_<mode><mask_name>"
  [(set (match_operand:<ssehalfvecmode> 0 "<store_mask_predicate>"
"=<store_mask_constraint>,v")
    (vec_select:<ssehalfvecmode>
      (match_operand:V8FI 1 "nonimmediate_operand" "v,m")
      (parallel [(const_int 0) (const_int 1)
            (const_int 2) (const_int 3)])))]
  "TARGET_AVX512F && !(MEM_P (operands[0]) && MEM_P (operands[1]))"
{
  if (<mask_applied>)
    return "vextract<shuffletype>64x4\t{$0x0, %1,
%0<mask_operand2>|%0<mask_operand2>, %1, 0x0}";
  else
    return "#";
}
;; ...
)

... may result in a split using YMMs from upper bank, hence emitting invalid
insn like
vextractf128 $0x1, %ymm31, %xmm0

We should tune insn constraints to avoid this issue.

[Bug target/67849] AVX512 Hitting upper-bank register on extract insn split

[kyukhin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67849

--- Comment #1 from Kirill Yukhin <kyukhin at gcc dot gnu.org> ---
Author: kyukhin
Date: Tue Oct  6 13:49:30 2015
New Revision: 228525

URL: https://gcc.gnu.org/viewcvs?rev=228525&root=gcc&view=rev
Log:
AVX-512. Avoid upper-bank registers when splitting vec_extract_lo instruction.

gcc/
        PR target/67849
        * config/i386/sse.md (define_split vec_select/V8FI): Restrict
        split for upper-bank registers when target does not support
        AVX512VL.
        (define_insn "vec_extract_lo_<mode><mask_name>"): Restrict
        split when target does not support AVX512VL.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/config/i386/sse.md

[Bug target/67849] AVX512 Hitting upper-bank register on extract insn split

[afomin.mailbox at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67849

Alexander Fomin <afomin.mailbox at gmail dot com> changed:

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

--- Comment #2 from Alexander Fomin <afomin.mailbox at gmail dot com> ---
See previous comment.

[Bug target/67849] AVX512 Hitting upper-bank register on extract insn split

[kyukhin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67849

--- Comment #3 from Kirill Yukhin <kyukhin at gcc dot gnu.org> ---
Author: kyukhin
Date: Mon Oct 12 11:03:56 2015
New Revision: 228709

URL: https://gcc.gnu.org/viewcvs?rev=228709&root=gcc&view=rev
Log:
        PR target/67849
gcc/
        * config/i386/sse.md (define_split vec_select/V8FI): Restrict
        split for upper-bank registers when target does not support
        AVX512VL.
        (define_insn "vec_extract_lo_<mode><mask_name>"): Restrict
        split when target does not support AVX512VL.
gcc/testsuite/
        * gcc.target/i386/pr67480.c: New test.


Added:
    branches/gcc-5-branch/gcc/testsuite/gcc.target/i386/pr67480.c
Modified:
    branches/gcc-5-branch/gcc/ChangeLog
    branches/gcc-5-branch/gcc/config/i386/sse.md
    branches/gcc-5-branch/gcc/testsuite/ChangeLog

[Bug target/67849] AVX512 Hitting upper-bank register on extract insn split

[afomin.mailbox at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67849

Alexander Fomin <afomin.mailbox at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |CLOSED

--- Comment #4 from Alexander Fomin <afomin.mailbox at gmail dot com> ---
See messages above.