From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 15614 invoked by alias); 22 Feb 2011 00:54:33 -0000 Received: (qmail 15605 invoked by uid 22791); 22 Feb 2011 00:54:33 -0000 X-SWARE-Spam-Status: No, hits=-2.8 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00 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; Tue, 22 Feb 2011 00:54:29 +0000 From: "cck0011 at yahoo dot com" To: gcc-bugs@gcc.gnu.org Subject: [Bug target/47825] SSE bitwise operations on floats work -g, fail -O3 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: target X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: cck0011 at yahoo dot com X-Bugzilla-Status: REOPENED 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 Date: Tue, 22 Feb 2011 01:53:00 -0000 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: 2011-02/txt/msg02541.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47825 --- Comment #7 from cck0011 at yahoo dot com 2011-02-22 00:54:17 UTC --- (In reply to comment #5) > The issue is that maskarray is initialized as array of ints but then you > load it as array of floats, the scheduler re-orders those so you see > a load from uninitialized stack: > [looks puzzled; reads info page for gcc -fstrict-aliasing for the N + 1th time; sudden look of comprehension dawns...] "taking a pointer and casting gives undefined result..." Thank you Richard. That makes sense now given the context... -) Thanks folks!