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From: "hjl.tools at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/99881] Regression compare -O2 -ftree-vectorize with -O2 on SKX/CLX
Date: Fri, 02 Apr 2021 14:29:27 +0000 [thread overview]
Message-ID: <bug-99881-4-L8699bcOTm@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-99881-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99881
H.J. Lu <hjl.tools at gmail dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
Last reconfirmed| |2021-04-02
Ever confirmed|0 |1
Status|UNCONFIRMED |NEW
--- Comment #1 from H.J. Lu <hjl.tools at gmail dot com> ---
(In reply to Hongtao.liu from comment #0)
> testcase is extracted from 557.xz_r
>
> void
> foo (int* __restrict a, int n, int c)
> {
> a[0] = n;
> a[1] = c;
> }
>
> gcc -O2 -ftree-vectorize -fvect-cost-model=very-cheap
>
> foo(int*, int, int):
> movd xmm0, esi
> movd xmm1, edx
> punpckldq xmm0, xmm1
> movq QWORD PTR [rdi], xmm0
> ret
>
> without vectorization
>
> foo(int*, int, int):
> mov DWORD PTR [rdi], esi
> mov DWORD PTR [rdi+4], edx
> ret
>
> cost model:
> scalar: 2 times scalar_store costs 24,
> vector: 1 times unaligned_store costs 12, vec_contruct 8
How is vec_contruct cost computed today?
next prev parent reply other threads:[~2021-04-02 14:29 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-02 3:49 [Bug target/99881] New: " crazylht at gmail dot com
2021-04-02 14:29 ` hjl.tools at gmail dot com [this message]
2021-04-02 19:34 ` [Bug target/99881] " hjl.tools at gmail dot com
2021-04-06 7:48 ` rguenth at gcc dot gnu.org
2021-04-06 10:06 ` crazylht at gmail dot com
2021-04-06 11:44 ` rguenth at gcc dot gnu.org
2021-07-28 2:48 ` cvs-commit at gcc dot gnu.org
2021-07-28 2:49 ` crazylht at gmail dot com
2021-07-28 22:47 ` jakub at gcc dot gnu.org
2021-07-29 1:09 ` crazylht at gmail dot com
2021-07-29 2:18 ` cvs-commit at gcc dot gnu.org
2021-08-19 2:32 ` crazylht at gmail dot com
2022-02-22 7:59 ` cvs-commit at gcc dot gnu.org
2022-02-22 8:00 ` rguenth at gcc dot gnu.org
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