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From: "nemo@self-evident.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/94962] Suboptimal AVX2 code for _mm256_zextsi128_si256(_mm_set1_epi8(-1))
Date: Tue, 19 May 2020 16:39:17 +0000 [thread overview]
Message-ID: <bug-94962-4-iqvmYFRGEI@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-94962-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94962
--- Comment #7 from Nemo <nemo@self-evident.org> ---
(In reply to Hongtao.liu from comment #6)
>
> vmovdqa xmm0, xmm0 is not redundant here, it would clear up 128-256 bit
> which is the meaning of `zext`.
No, it is redundant because "vpcmpeqd xmm0, xmm0, xmm0" already zeroes out the
high lane of ymm0.
next prev parent reply other threads:[~2020-05-19 16:39 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-05 21:41 [Bug tree-optimization/94962] New: " nemo@self-evident.org
2020-05-18 8:41 ` [Bug target/94962] " crazylht at gmail dot com
2020-05-18 9:37 ` jakub at gcc dot gnu.org
2020-05-18 9:55 ` crazylht at gmail dot com
2020-05-18 10:01 ` crazylht at gmail dot com
2020-05-18 15:43 ` nemo@self-evident.org
2020-05-19 6:14 ` crazylht at gmail dot com
2020-05-19 16:39 ` nemo@self-evident.org [this message]
2022-09-23 5:29 ` cvs-commit at gcc dot gnu.org
2022-09-23 5:32 ` crazylht at gmail dot com
2022-09-26 5:30 ` cvs-commit at gcc dot gnu.org
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