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From: "crazylht at gmail dot com" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug target/100711] Miss optimization for pandn Date: Thu, 25 May 2023 06:52:38 +0000 [thread overview] Message-ID: <bug-100711-4-Pay8JsBhyQ@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-100711-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100711 --- Comment #9 from Hongtao.liu <crazylht at gmail dot com> --- (In reply to jbeulich from comment #8) > Since the commit doesn't really explain it (maybe it's obvious to others, > but it isn't to me), may I ask why two splitters were introduced, yet then > still not covering all possible modes? VI48_128 only covers two of the four > possible SSE2 modes, while VI124_AVX2 leaves out all DI-element-size ones as > well as all 512-bit ones. Shouldn't both be folded, using VI_AVX2 as the > mode iterator? We don't have single instruction for V8HI/V16QImode broadcast without AVX2, that's why the first splitter only have VI48_128. And yes, for the second splitter, I think we should use VI_AVX2 to cover all modes. > > As an aside, it is also interesting that the 1st splitter uses TARGET_SSE > without the corresponding testcase limiting itself to just SSE. When > building that testcase with SSE2 turned off, foo() uses shufps and andnps as > expected, but the splitter doesn't appear to come into play at all for > bar(), when really it is only the broadcast that needs synthesizing, while > andnps can be used regardless of mode.
next prev parent reply other threads:[~2023-05-25 6:52 UTC|newest] Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-05-21 2:22 [Bug target/100711] New: " crazylht at gmail dot com 2021-05-21 6:42 ` [Bug target/100711] " rguenth at gcc dot gnu.org 2021-05-21 10:36 ` segher at gcc dot gnu.org 2021-05-25 5:40 ` crazylht at gmail dot com 2021-05-25 6:52 ` crazylht at gmail dot com 2021-05-25 10:09 ` segher at gcc dot gnu.org 2021-11-30 8:37 ` cvs-commit at gcc dot gnu.org 2021-11-30 8:46 ` crazylht at gmail dot com 2023-05-24 8:42 ` jbeulich at suse dot com 2023-05-25 6:52 ` crazylht at gmail dot com [this message] 2023-05-25 8:36 ` jbeulich at suse dot com 2023-05-25 8:50 ` crazylht at gmail dot com 2023-05-27 9:28 ` cvs-commit at gcc dot gnu.org 2023-07-05 7:49 ` cvs-commit at gcc dot gnu.org 2023-07-05 7:49 ` cvs-commit at gcc dot gnu.org 2023-07-05 7:49 ` cvs-commit at gcc dot gnu.org
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