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From: "changpeng dot fang at amd dot com" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug middle-end/43182] GCC does not pull out a[0] from loop that changes a[i] for i:[1,n] Date: Fri, 26 Feb 2010 18:53:00 -0000 [thread overview] Message-ID: <20100226185342.13201.qmail@sourceware.org> (raw) In-Reply-To: <bug-43182-18740@http.gcc.gnu.org/bugzilla/> ------- Comment #4 from changpeng dot fang at amd dot com 2010-02-26 18:53 ------- Here is another similar case but more general. We know that a(j) and a(i) never access the same memory location. intel ifort can vectorize this triangular loop: do 10 j = 1,n do 20 i = j+1, n a(i) = a(i) - aa(i,j) * a(j) 20 continue 10 continue -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43182
next prev parent reply other threads:[~2010-02-26 18:53 UTC|newest] Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top 2010-02-25 23:37 [Bug middle-end/43182] New: gcc could not vectorize this simple loop (un-handled data-ref) changpeng dot fang at amd dot com 2010-02-25 23:45 ` [Bug middle-end/43182] " pinskia at gcc dot gnu dot org 2010-02-25 23:50 ` [Bug middle-end/43182] GCC does not pull out a[0] from loop that changes a[i] for i:[1,n] pinskia at gcc dot gnu dot org 2010-02-25 23:54 ` pinskia at gcc dot gnu dot org 2010-02-26 18:53 ` changpeng dot fang at amd dot com [this message] 2010-02-26 18:55 ` pinskia at gcc dot gnu dot org 2010-02-26 19:06 ` changpeng dot fang at amd dot com [not found] <bug-43182-4@http.gcc.gnu.org/bugzilla/> 2021-07-26 7:45 ` pinskia at gcc dot gnu.org
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