From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 28477 invoked by alias); 10 Dec 2008 18:24:57 -0000 Received: (qmail 26593 invoked by alias); 10 Dec 2008 18:23:37 -0000 Date: Wed, 10 Dec 2008 18:24:00 -0000 Message-ID: <20081210182337.26592.qmail@sourceware.org> X-Bugzilla-Reason: CC References: Subject: [Bug tree-optimization/32044] [4.3/4.4 Regression] final value replacement too aggressive for e.g. targets with no native div/mod insns In-Reply-To: Reply-To: gcc-bugzilla@gcc.gnu.org To: gcc-bugs@gcc.gnu.org From: "rakdver at kam dot mff dot cuni dot cz" 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: 2008-12/txt/msg01066.txt.bz2 ------- Comment #54 from rakdver at kam dot mff dot cuni dot cz 2008-12-10 18:23 ------- Subject: Re: [4.3/4.4 Regression] final value replacement too aggressive for e.g. targets with no native div/mod insns > Zdenek, it would certainly be helpful to have the original justification for > your change available. Unfortunately, I do not remember the exact problems (it is almost two years since that change was made). Adding back expression_expensive_p in some conservative form (e.g., checking that the computation involves division, perhaps excluding divisions by a power of two) seems like the easiest way to fix this problem now. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32044