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From: "irar at il dot ibm.com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/51499] vectorizer missing simple case
Date: Mon, 12 Dec 2011 11:23:00 -0000	[thread overview]
Message-ID: <bug-51499-4-7ZHssjwl3A@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-51499-4@http.gcc.gnu.org/bugzilla/>

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51499

--- Comment #9 from Ira Rosen <irar at il dot ibm.com> 2011-12-12 11:13:24 UTC ---
(In reply to comment #7)
> 
> In some cases it might be necessary but not here:
> 
>  sum1+=a;
>  sum2+=a;
> 
> gives exactly the same result as
> 
>  (sum1, sum2) += (a, a);
> 

So, you are suggesting to remove the need in flag_associative_math for fp for
cases when a reduction computation is already unrolled by the vectorization
factor. Sounds reasonable to me.


  parent reply	other threads:[~2011-12-12 11:13 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-12-10 18:39 [Bug tree-optimization/51499] New: " fb.programming at gmail dot com
2011-12-11  8:29 ` [Bug tree-optimization/51499] " irar at il dot ibm.com
2011-12-11  8:48 ` fb.programming at gmail dot com
2011-12-11  9:05 ` irar at il dot ibm.com
2011-12-11 12:13 ` fb.programming at gmail dot com
2011-12-11 13:39 ` irar at il dot ibm.com
2011-12-11 14:55 ` dominiq at lps dot ens.fr
2011-12-11 16:58 ` fb.programming at gmail dot com
2011-12-12 11:13 ` irar at il dot ibm.com
2011-12-12 11:23 ` irar at il dot ibm.com [this message]
2011-12-12 11:27 ` rguenth at gcc dot gnu.org
2011-12-12 12:21 ` irar at il dot ibm.com
2011-12-12 13:10 ` dominiq at lps dot ens.fr
2011-12-12 14:31 ` fb.programming at gmail dot com
2011-12-13 16:33 ` irar at il dot ibm.com
2021-08-07  5:19 ` [Bug tree-optimization/51499] -Ofast does not vectorize while -O3 does pinskia at gcc dot gnu.org

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