From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 31090 invoked by alias); 16 Dec 2007 18:01:21 -0000 Received: (qmail 31082 invoked by uid 22791); 16 Dec 2007 18:01:20 -0000 X-Spam-Check-By: sourceware.org Received: from sunsite.ms.mff.cuni.cz (HELO sunsite.mff.cuni.cz) (195.113.15.26) by sourceware.org (qpsmtpd/0.31) with ESMTP; Sun, 16 Dec 2007 18:01:15 +0000 Received: from sunsite.mff.cuni.cz (localhost.localdomain [127.0.0.1]) by sunsite.mff.cuni.cz (8.13.8/8.13.8) with ESMTP id lBGI6rrR024240; Sun, 16 Dec 2007 19:06:53 +0100 Received: (from jakub@localhost) by sunsite.mff.cuni.cz (8.13.8/8.13.8/Submit) id lBGI6rWe024235; Sun, 16 Dec 2007 19:06:53 +0100 Date: Sun, 16 Dec 2007 18:10:00 -0000 From: Jakub Jelinek To: Eric Botcazou Cc: gcc@gcc.gnu.org Subject: Re: Problem with SSA inlining and default defs Message-ID: <20071216180653.GE2947@sunsite.mff.cuni.cz> Reply-To: Jakub Jelinek References: <200712161854.29543.ebotcazou@adacore.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200712161854.29543.ebotcazou@adacore.com> User-Agent: Mutt/1.4.2.2i Mailing-List: contact gcc-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-owner@gcc.gnu.org X-SW-Source: 2007-12/txt/msg00472.txt.bz2 On Sun, Dec 16, 2007 at 06:54:29PM +0100, Eric Botcazou wrote: > How SSA inlining and default defs for uninitialized variables are supposed to > interact? Suppose you have the following situation > > BB0 ... > | \ > (ab) | BB1 s_2 = f(s_1(D)) > | / > BB2 s_3 = PHI > > in a function that gets inlined into a loop. The liveness of s_1(D) in BB0 > will propagate to BB2 along the backwards edge and you get overlapping live > ranges for s_1(D) and s_3. If s_1(D) is SSA_NAME_OCCURS_IN_ABNORMAL_PHI, the > compilation will abort during SSA coalescing because they must be coalesced. This sounds like PR31081. Jakub