Re: [GCC 13 PATCH] PR target/109973: CCZmode and CCCmode variants of [v]ptest.

[Uros Bizjak <ubizjak@gmail.com>]

On Wed, Jul 19, 2023 at 2:21 PM Richard Biener
<richard.guenther@gmail.com> wrote:
>
> On Sun, Jun 11, 2023 at 12:55 AM Roger Sayle <roger@nextmovesoftware.com> wrote:
> >
> >
> > This is a backport of the fixes for PR target/109973 and PR target/110083.
> >
> > This backport to the releases/gcc-13 branch has been tested on
> > x86_64-pc-linux-gnu with make bootstrap and make -k check, both with and
> > without --target_board=unix{-m32} with no new failures.  Ok for gcc-13,
> > or should we just close PR 109973 in Bugzilla?
>
> As alternative solution for the GCC 13 branch I have tested reverting
> r13-2006-ga56c1641e9d25e successfully.  Can we choose between the
> options please?  Sorry I'm only bringing this up now but 13.2 RC is due
> tomorrow.
>
> Thank you,
> Richard.
>
> >
> >
> > 2023-06-10  Roger Sayle  <roger@nextmovesoftware.com>
> >             Uros Bizjak  <ubizjak@gmail.com>
> >
> > gcc/ChangeLog
> >         PR target/109973
> >         PR target/110083
> >         * config/i386/i386-builtin.def (__builtin_ia32_ptestz128): Use new
> >         CODE_for_sse4_1_ptestzv2di.
> >         (__builtin_ia32_ptestc128): Use new CODE_for_sse4_1_ptestcv2di.
> >         (__builtin_ia32_ptestz256): Use new CODE_for_avx_ptestzv4di.
> >         (__builtin_ia32_ptestc256): Use new CODE_for_avx_ptestcv4di.
> >         * config/i386/i386-expand.cc (ix86_expand_branch): Use CCZmode
> >         when expanding UNSPEC_PTEST to compare against zero.
> >         * config/i386/i386-features.cc (scalar_chain::convert_compare):
> >         Likewise generate CCZmode UNSPEC_PTESTs when converting comparisons.
> >         Update or delete REG_EQUAL notes, converting CONST_INT and
> >         CONST_WIDE_INT immediate operands to a suitable CONST_VECTOR.
> >         (general_scalar_chain::convert_insn): Use CCZmode for COMPARE
> > result.
> >         (timode_scalar_chain::convert_insn): Use CCZmode for COMPARE result.
> >         * config/i386/i386-protos.h (ix86_match_ptest_ccmode): Prototype.
> >         * config/i386/i386.cc (ix86_match_ptest_ccmode): New predicate to
> >         check for suitable matching modes for the UNSPEC_PTEST pattern.
> >         * config/i386/sse.md (define_split): When splitting UNSPEC_MOVMSK
> >         to UNSPEC_PTEST, preserve the FLAG_REG mode as CCZ.
> >         (*<sse4_1>_ptest<mode>): Add asterisk to hide define_insn.  Remove
> >         ":CC" mode of FLAGS_REG, instead use ix86_match_ptest_ccmode.
> >         (<sse4_1>_ptestz<mode>): New define_expand to specify CCZ.
> >         (<sse4_1>_ptestc<mode>): New define_expand to specify CCC.
> >         (<sse4_1>_ptest<mode>): A define_expand using CC to preserve the
> >         current behavior.
> >         (*ptest<mode>_and): Specify CCZ to only perform this optimization
> >         when only the Z flag is required.
> >
> > gcc/testsuite/ChangeLog
> >         PR target/109973
> >         PR target/110083
> >         * gcc.target/i386/pr109973-1.c: New test case.
> >         * gcc.target/i386/pr109973-2.c: Likewise.
> >         * gcc.target/i386/pr110083.c: Likewise.

Yes, I would rather have the offending patch reverted on gcc-13.

Uros.