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From: "crazylht at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/101097] Vectorizer is too eager to use vec_unpack
Date: Thu, 17 Jun 2021 07:29:22 +0000	[thread overview]
Message-ID: <bug-101097-4-pmtSFQC66X@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-101097-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101097

--- Comment #6 from Hongtao.liu <crazylht at gmail dot com> ---
(In reply to Richard Biener from comment #5)
> (In reply to Uroš Bizjak from comment #3)
> > Created attachment 51031 [details]
> > Pack/unpack patterns for 8-byte vectors
> > 
> > FYI, this patch adds pack/unpack patterns for 8-byte vectors. It will fail:
> > 
> > FAIL: gcc.target/i386/pr97249-1.c scan-assembler-times (?n)vpmovzxbw[
> > \\\\t]+\\\\(.*%xmm[0-9] 2
> > FAIL: gcc.target/i386/pr97249-1.c scan-assembler-times (?n)vpmovzxwd[
> > \\\\t]+\\\\(.*%xmm[0-9] 2
> > 
> > due to the mentioned issue.
> 
> You can add #pragma GCC unroll 8/4 to "fix" that and add a comment this test
> tests BB vectorization.  Loop vectorization would have failed even before
> the patch (and now succeeds, but with less optimal code).

I just to want to classify the test is used to test another optimization which
rely on either loop vectorization or slp. it means it's ok to add unroll pragma
here.

  parent reply	other threads:[~2021-06-17  7:29 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-16 15:13 [Bug tree-optimization/101097] New: " ubizjak at gmail dot com
2021-06-17  6:38 ` [Bug tree-optimization/101097] " rguenth at gcc dot gnu.org
2021-06-17  7:00 ` crazylht at gmail dot com
2021-06-17  7:08 ` ubizjak at gmail dot com
2021-06-17  7:19 ` rguenth at gcc dot gnu.org
2021-06-17  7:21 ` rguenth at gcc dot gnu.org
2021-06-17  7:29 ` crazylht at gmail dot com [this message]
2021-06-17  7:30 ` crazylht at gmail dot com
2021-06-17  7:32 ` ubizjak at gmail dot com
2021-06-17  7:34 ` crazylht at gmail dot com
2021-06-17  7:42 ` rguenth at gcc dot gnu.org
2021-06-22 12:43 ` rsandifo at gcc dot gnu.org
2021-07-01  2:46 ` crazylht at gmail dot com
2021-07-01  2:53 ` crazylht at gmail dot com

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