From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-return-57183-listarch-gcc=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 32410 invoked by alias); 26 Jul 2002 08:56:22 -0000
Mailing-List: contact gcc-help@gcc.gnu.org; run by ezmlm
Precedence: bulk
List-Archive: <http://gcc.gnu.org/ml/gcc/>
List-Post: <mailto:gcc@gcc.gnu.org>
List-Help: <http://gcc.gnu.org/ml/>
Sender: gcc-owner@gcc.gnu.org
Received: (qmail 31913 invoked from network); 26 Jul 2002 08:55:05 -0000
Received: from unknown (HELO fw-cam.cambridge.arm.com) (193.131.176.3)
  by sources.redhat.com with SMTP; 26 Jul 2002 08:55:05 -0000
Received: by fw-cam.cambridge.arm.com; id JAA04009; Fri, 26 Jul 2002 09:54:59 +0100 (BST)
Received: from unknown(172.16.1.2) by fw-cam.cambridge.arm.com via smap (V5.5)
	id xma003898; Fri, 26 Jul 02 09:54:54 +0100
Received: from cam-mail2.cambridge.arm.com (cam-mail2 [172.16.1.91])
	by cam-admin0.cambridge.arm.com (8.9.3/8.9.3) with ESMTP id JAA15259;
	Fri, 26 Jul 2002 09:54:53 +0100 (BST)
Received: from sun18.cambridge.arm.com (sun18.cambridge.arm.com [172.16.2.18])
	by cam-mail2.cambridge.arm.com (8.9.3/8.9.3) with ESMTP id JAA14169;
	Fri, 26 Jul 2002 09:54:52 +0100 (BST)
Message-Id: <200207260854.JAA14169@cam-mail2.cambridge.arm.com>
To: Richard Henderson <rth@redhat.com>
cc: Momchil Velikov <velco@fadata.bg>, Alan Modra <amodra@bigpond.net.au>,
        gcc@gcc.gnu.org, Richard.Earnshaw@arm.com
Reply-To: Richard.Earnshaw@arm.com
Organization: ARM Ltd.
X-Telephone: +44 1223 400569 (direct+voicemail), +44 1223 400400 (switchbd)
X-Fax: +44 1223 400410
X-Address: ARM Ltd., 110 Fulbourn Road, Cherry Hinton, Cambridge CB1 9NJ.
X-Url: http://www.arm.com/
Subject: Re: Undefined behavior in 950605-1.c 
In-reply-to: Your message of "Thu, 25 Jul 2002 10:56:12 PDT."
             <20020725105612.A27073@redhat.com> 
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Date: Fri, 26 Jul 2002 14:47:00 -0000
From: Richard Earnshaw <rearnsha@arm.com>
X-SW-Source: 2002-07/txt/msg01272.txt.bz2


> PROMOTE_MODE has nothing to do with C types.  It's for efficiency
> in the generated rtl *only*. 

I believe it can also be part of the ABI specification, so someone writing 
assembler would be able to tell the difference, and a compiler can assume 
that a caller has done the promotion (so saving a repeat promotion).

> If a strictly conforming program can
> notice the existance of PROMOTE_MODE, there is a bug.

Agreed.

R.