From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 31941 invoked by alias); 25 Aug 2011 22:09:08 -0000 Received: (qmail 31931 invoked by uid 22791); 25 Aug 2011 22:09:06 -0000 X-SWARE-Spam-Status: No, hits=-2.8 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00,TW_JN X-Spam-Check-By: sourceware.org Received: from localhost (HELO gcc.gnu.org) (127.0.0.1) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Thu, 25 Aug 2011 22:08:53 +0000 From: "oleg.smolsky at gmail dot com" To: gcc-bugs@gcc.gnu.org Subject: [Bug target/50182] Performance degradation from gcc 4.1 (x86_64) Date: Thu, 25 Aug 2011 22:48:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: target X-Bugzilla-Keywords: missed-optimization X-Bugzilla-Severity: normal X-Bugzilla-Who: oleg.smolsky at gmail dot com X-Bugzilla-Status: UNCONFIRMED X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated Content-Type: text/plain; charset="UTF-8" MIME-Version: 1.0 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: 2011-08/txt/msg02135.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50182 --- Comment #10 from Oleg Smolsky 2011-08-25 22:08:49 UTC --- BTW, the uint16_t test also got slower for the same very reason. Here is the inner-most loop generated by g++4.6: text:0000000000400DA0 loc_400DA0: .text:0000000000400DA0 add eax, 0Ah .text:0000000000400DA3 add ax, [rdx] .text:0000000000400DA6 add rdx, 2 .text:0000000000400DAA cmp rdx, 5092E0h .text:0000000000400DB1 jnz short loc_400DA0