From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 15872 invoked by alias); 13 Feb 2003 21:09:13 -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 15860 invoked from network); 13 Feb 2003 21:09:13 -0000 Received: from unknown (HELO nile.gnat.com) (205.232.38.5) by 172.16.49.205 with SMTP; 13 Feb 2003 21:09:13 -0000 Received: by nile.gnat.com (Postfix, from userid 338) id 2D370F2DC2; Thu, 13 Feb 2003 16:09:13 -0500 (EST) To: kenner@vlsi1.ultra.nyu.edu, roger@www.eyesopen.com Subject: Re: [PATCH] Document arithmetic overflow semantics Cc: gcc-patches@gcc.gnu.org, gcc@gcc.gnu.org Message-Id: <20030213210913.2D370F2DC2@nile.gnat.com> Date: Thu, 13 Feb 2003 21:14:00 -0000 From: dewar@gnat.com (Robert Dewar) X-SW-Source: 2003-02/txt/msg01006.txt.bz2 > The issue is GCC's internal representations, which shouldn't suffer > from the same issue of poorly defined languages. Hence, if CSE sees > "x = i++; i = x" it had better understand exactly what "i = i++" means > at the RTL-level. One might hope that the interpretation of RTL and > TREEs are independent of the source language and target architecture. Most certainly the meaning should be specified and exact, but also it can most certainly be non-deterministic with several possbile outcomes.