From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 13688 invoked by alias); 28 May 2002 13:56:06 -0000 Mailing-List: contact gcc-prs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Archive: List-Post: List-Help: Sender: gcc-prs-owner@gcc.gnu.org Received: (qmail 13533 invoked by uid 71); 28 May 2002 13:56:04 -0000 Date: Tue, 28 May 2002 07:10:00 -0000 Message-ID: <20020528135604.13531.qmail@sources.redhat.com> To: nobody@gcc.gnu.org Cc: gcc-prs@gcc.gnu.org, From: Glen Nakamura Subject: Re: optimization/6822: GCC 3.1.1 - Internal compiler error in extract_insn, at recog.c:2132 Reply-To: Glen Nakamura X-SW-Source: 2002-05/txt/msg00903.txt.bz2 List-Id: The following reply was made to PR optimization/6822; it has been noted by GNATS. From: Glen Nakamura To: gcc-gnats@gcc.gnu.org, gcc-bugs@gcc.gnu.org Cc: Subject: Re: optimization/6822: GCC 3.1.1 - Internal compiler error in extract_insn, at recog.c:2132 Date: Tue, 28 May 2002 03:54:54 -1000 http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=6822 I believe the following patch is the cause of this PR: 2002-05-15 Eric Botcazou * fold-const.c (fold) [LT_EXPR]: Move the transformation of a comparison against the highest or lowest integer value before the 'X >= CST to X > (CST - 1)' and 'X < CST to X <= (CST - 1)' transformation and that of an unsigned comparison against 0 right after. Previously, unsigned X < 128 would be converted to unsigned X <= 127 and then optimized to signed X >= 0. After changing the order of the transformations, the compiler only reduces the expression to X <= 127 ??? The result is the reported ICE. This could very well be a latent bug in other parts of the compiler, but it seems the change results in missed opportunities to simplify expressions. I'll post an alternative patch in my next message... - Glen Nakamura