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From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/63743] Thumb1: big regression for float operators by r216728 Date: Wed, 05 Nov 2014 12:34:00 -0000 [thread overview] Message-ID: <bug-63743-4-OtoedQmuey@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-63743-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63743 Richard Biener <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |rguenth at gcc dot gnu.org --- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> --- This is just operand canonicalization according to tree_swap_operands which is now consistently applied. It was a bug that it wasn't applied before (the usual offender here is SSA rewriting that doesn't fold "changed" statements nor re-canonicalizes). You are just (un)lucky btw, try both double test1 (double x, double y) { double tem = x + y; double tem2 = x; return tem2 * tem; } and double test1 (double x, double y) { double tem = x + y; double tem2 = x; return tem * tem2; } there is nothing that forces ordering in the way you would prefer it. So as Jakub says - this needs addressing in RTL expansion and/or TER and SSA coalescing.
next prev parent reply other threads:[~2014-11-05 12:34 UTC|newest] Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top 2014-11-05 8:20 [Bug tree-optimization/63743] New: " zhenqiang.chen at arm dot com 2014-11-05 8:35 ` [Bug tree-optimization/63743] " jakub at gcc dot gnu.org 2014-11-05 9:40 ` zhenqiang.chen at arm dot com 2014-11-05 9:51 ` jakub at gcc dot gnu.org 2014-11-05 10:21 ` zhenqiang.chen at arm dot com 2014-11-05 12:34 ` rguenth at gcc dot gnu.org [this message] 2014-12-26 13:54 ` ysrumyan at gmail dot com 2015-01-15 14:56 ` rguenth at gcc dot gnu.org 2015-01-28 8:01 ` thopre01 at gcc dot gnu.org 2015-03-04 6:58 ` thopre01 at gcc dot gnu.org 2015-03-09 1:32 ` thopre01 at gcc dot gnu.org 2015-03-11 5:06 ` thopre01 at gcc dot gnu.org
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