From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 10608 invoked by alias); 30 Dec 2009 23:34:20 -0000 Received: (qmail 10568 invoked by uid 48); 30 Dec 2009 23:34:08 -0000 Date: Wed, 30 Dec 2009 23:34:00 -0000 Message-ID: <20091230233408.10567.qmail@sourceware.org> X-Bugzilla-Reason: CC References: Subject: [Bug tree-optimization/42494] [4.4 Regression] Missed dead-code-elimination In-Reply-To: Reply-To: gcc-bugzilla@gcc.gnu.org To: gcc-bugs@gcc.gnu.org From: "rguenth at gcc dot 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: 2009-12/txt/msg02851.txt.bz2 ------- Comment #4 from rguenth at gcc dot gnu dot org 2009-12-30 23:34 ------- The issue is that we do not do predicated value-numbering so we need multiple invocations of it. Which all of FRE, DOM and PRE do - but PRE is not run at -Os in 4.4. And yes, the optimization done by 4.5 is correct. You could say "fixed" in 4.5 - or wait for someone to implement predicated value-numbering to also fix a testcase with one more if (outcnt == 1) func (); -- rguenth at gcc dot gnu dot org changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |matz at gcc dot gnu dot org http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42494