From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 970 invoked by alias); 17 Dec 2014 15:12:37 -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 Received: (qmail 690 invoked by uid 48); 17 Dec 2014 15:12:32 -0000 From: "ebotcazou at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug target/64331] regcprop propagates registers noted as REG_DEAD Date: Wed, 17 Dec 2014 15:12:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: target X-Bugzilla-Version: 5.0 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: ebotcazou 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: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-SW-Source: 2014-12/txt/msg02009.txt.bz2 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64331 --- Comment #5 from Eric Botcazou --- > Is it just REG_USED/REG_DEAD notes, or is register liveliness > (df_regs_ever_live_p etc..) also not guaranteed to be up to date? These REG_UNUSED/REG_DEAD notes are special because they are not maintained incrementally by the DF framework, i.e. the insn manipulation routines don't cause them to be updated, so they are really valid only just after they are recomputed. The rest of the liveness info is updated incrementally (if DF is asked to).