From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 28158 invoked by alias); 6 Jan 2010 23:00:30 -0000 Received: (qmail 28082 invoked by uid 48); 6 Jan 2010 23:00:17 -0000 Date: Wed, 06 Jan 2010 23:00:00 -0000 Message-ID: <20100106230017.28081.qmail@sourceware.org> X-Bugzilla-Reason: CC References: Subject: [Bug rtl-optimization/42621] [4.4/4.5 Regression] Computed gotos on AMD 800% slower In-Reply-To: Reply-To: gcc-bugzilla@gcc.gnu.org To: gcc-bugs@gcc.gnu.org From: "fredrik dot svahn at gmail dot com" 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: 2010-01/txt/msg00713.txt.bz2 ------- Comment #7 from fredrik dot svahn at gmail dot com 2010-01-06 23:00 ------- Summary: The patch works great when building gcc from trunk (revision 155680). Both supplied test program and real application are optimized. With gcc-4.4.2 I get the optimization for the test program only with e.g. -march=athlon64 or -mtune=native (which is an improvement, previously I could not get it to work even with these options). Without -mtune/-march optimization seems to bail out on the following check in bb-reorder.c@@duplicate_computed_gotos(void): /* Obviously the block has to end in a computed jump. */ if (!computed_jump_p (BB_END (bb))) continue; I assume the patch was written for 4.5 so maybe testing it on 4.4.2 is a bit premature. Hope it helps anyway. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42621