From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 12993 invoked by alias); 13 Feb 2009 20:10:09 -0000 Received: (qmail 12905 invoked by alias); 13 Feb 2009 20:09:58 -0000 Date: Fri, 13 Feb 2009 20:10:00 -0000 Message-ID: <20090213200958.12904.qmail@sourceware.org> X-Bugzilla-Reason: CC References: Subject: [Bug tree-optimization/33928] [4.3/4.4 Regression] 30% performance slowdown in floating-point code caused by r118475 In-Reply-To: Reply-To: gcc-bugzilla@gcc.gnu.org To: gcc-bugs@gcc.gnu.org From: "bonzini at gnu dot org" Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-bugs-owner@gcc.gnu.org X-SW-Source: 2009-02/txt/msg01241.txt.bz2 ------- Comment #48 from bonzini at gnu dot org 2009-02-13 20:09 ------- Subject: Re: [4.3/4.4 Regression] 30% performance slowdown in floating-point code caused by r118475 > Yes. I don't see why the optimizations in CSE, which were relatively > cheap and which were effective for this case, needed to be disabled when > FWPROP was added without, evidently, understanding why FWPROP does not > do what CSE was already doing. Just to mention it, fwprop saved 3% of compile time. That's not "cheap". It was also tested with SPEC and Nullstone on several architectures. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33928