From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 32151 invoked by alias); 1 Sep 2004 12:12:24 -0000 Mailing-List: contact gcc-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Archive: List-Post: List-Help: Sender: gcc-owner@gcc.gnu.org Received: (qmail 32114 invoked from network); 1 Sep 2004 12:12:23 -0000 Received: from unknown (HELO smtp.uk.superh.com) (193.128.105.170) by sourceware.org with SMTP; 1 Sep 2004 12:12:23 -0000 Received: from sh-uk-ex01.uk.w2k.superh.com (sh-uk-ex01 [192.168.16.17]) by smtp.uk.superh.com (8.12.10/8.12.10) with ESMTP id i81CCLod025701; Wed, 1 Sep 2004 13:12:21 +0100 (BST) Received: from chloe.uk.w2k.superh.com ([192.168.17.40]) by sh-uk-ex01.uk.w2k.superh.com with Microsoft SMTPSVC(5.0.2195.6713); Wed, 1 Sep 2004 13:14:44 +0100 Received: (from renneckej@localhost) by chloe.uk.w2k.superh.com (8.11.6/8.11.6) id i81CFc711032; Wed, 1 Sep 2004 13:15:38 +0100 From: Joern Rennecke Message-Id: <200409011215.i81CFc711032@chloe.uk.w2k.superh.com> Subject: Re: On -ftrapv vs. libcalls... To: wilson@specifixinc.com (James E Wilson) Date: Wed, 01 Sep 2004 12:12:00 -0000 Cc: rakdver@atrey.karlin.mff.cuni.cz (Zdenek Dvorak), gcc@gcc.gnu.org In-Reply-To: <4134C9B6.30201@specifixinc.com> from "James E Wilson" at Aug 31, 2004 11:55:50 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 01 Sep 2004 12:14:44.0943 (UTC) FILETIME=[446975F0:01C4901D] X-SW-Source: 2004-09/txt/msg00030.txt.bz2 > there. Or else the REG_EQUAL note should be changed to be accurate, but > that would probably require creating a new RTL operator, e.g. multv. No, that wouldn't work, because REG_EQUAL describes a value, but never a side effect. In general, a mulv can't be hoisted out of a loop that might have zero iterations, but that is not apparent when you have a LIBCALL / RETVAL sequence with only a REG_EQUAL note to describe the computation.