From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 11273 invoked by alias); 26 Oct 2012 07:42:32 -0000 Received: (qmail 11198 invoked by uid 48); 26 Oct 2012 07:42:09 -0000 From: "aoliva at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug debug/54953] [4.8 Regression] New sra-1.c FAILs on powerpc Date: Fri, 26 Oct 2012 07:42:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: debug X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: aoliva at gcc dot gnu.org X-Bugzilla-Status: NEW X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: 4.8.0 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: 2012-10/txt/msg02418.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54953 --- Comment #2 from Alexandre Oliva 2012-10-26 07:42:07 UTC --- Without your poposed change, AFTER_WITH_REG is only used while adding REG_UNUSED marks to REG defs. That the REG def is unused means it's going to be discarded and, when it is, either the debug temp will be reset altogether, or we'll propagate the expression stored in the REG to uses of the REG (e.g., the debug use, if we omit the debug temp, or the debug temp, if we needlessly add it), or we (should?) emit another debug temp BEFORE_WITH_VALUE and use that instead of the REG (in the orginal debug use or in the needless debug temp). In any of these cases, the debug temp is useless. All that siad, it's probably not a terribly important optimization, so if the above wouldn't make sense in a comment before the questionable hunk, we might as well drop it. Adding REG_FORCE for this new use is probably fine too.