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From: Uros Bizjak <ubizjak@gmail.com>
To: Roger Sayle <roger@nextmovesoftware.com>
Cc: GCC Patches <gcc-patches@gcc.gnu.org>
Subject: Re: [x86 PATCH] Fix libitm.c/memset-1.c test fails with new peephole2s.
Date: Sun, 13 Mar 2022 18:41:07 +0100	[thread overview]
Message-ID: <CAFULd4aOL=Hu=-UYJORAF04p=rqEOWS1xBs7rnsXj1vovsaxag@mail.gmail.com> (raw)
In-Reply-To: <003401d83642$0b222c40$216684c0$@nextmovesoftware.com>

On Sat, Mar 12, 2022 at 7:50 PM Roger Sayle <roger@nextmovesoftware.com> wrote:
>
>
> My sincere apologies for the breakage, but alas handling SImode in the
> recently added "xorl;movb -> movzbl" peephole2 turns out to be slightly
> more complicated that just using SWI48 as a mode iterator.  I'd failed
> to check the machine description carefully, but the *zero_extend<mode>si2
> define_insn is conditionally defined, based on x86 target tuning using
> TARGET_ZERO_EXTEND_WITH_AND, and therefore unavailable on 486 and pentium
> unless optimizing the code for size.  It turns out that the libitm testsuite
> specifies -m486 with make check RUNTESTFLAGS="--target_board='unix{-m32}'"
> and therefore encounters/catches my oversight.
>
> Fixed by adding the appropriate conditions to the new peephole2 patterns.
> It don't think it's worth the effort to provide an equivalent optimization
> for
> these (very) old architectures.
>
> Tested on x86_64-pc-linux-gnu with make bootstrap and make -k check
> with no new failures.  Confirmed using RUNTESTFLAGS that this
> fixes the above failure, and the recently added testcase with -march=i486.
> Ok for mainline?
>
>
> 2022-03-12  Roger Sayle  <roger@nextmovesoftware.com>
>
> gcc/ChangeLog
>         * config/i386/i386.md (peephole2 xorl;movb -> movzbl): Disable
>         transformation when *zero_extend<mode>si2 is not available.
>
> gcc/testsuite/ChangeLog
>         * gcc.target/i386/pr98335.c: Skip this test if tuning for i486
>         or pentium, and not optimizing for size.

OK, but please use:

<MODE>mode != SImode

instead of

<SWI48:MODE_SIZE> != 4

Thanks,
Uros.

      reply	other threads:[~2022-03-13 17:41 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-03-12 18:50 Roger Sayle
2022-03-13 17:41 ` Uros Bizjak [this message]

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