From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 15561 invoked by alias); 17 Dec 2013 09:06:31 -0000 Mailing-List: contact gcc-help-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-help-owner@gcc.gnu.org Received: (qmail 15549 invoked by uid 89); 17 Dec 2013 09:06:30 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-4.4 required=5.0 tests=AWL,BAYES_00,RP_MATCHES_RCVD,SPF_HELO_PASS,SPF_PASS autolearn=ham version=3.3.2 X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Tue, 17 Dec 2013 09:06:30 +0000 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id rBH96SAB003595 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Tue, 17 Dec 2013 04:06:28 -0500 Received: from zebedee.pink (ovpn-113-92.phx2.redhat.com [10.3.113.92]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id rBH96QOS011094; Tue, 17 Dec 2013 04:06:26 -0500 Message-ID: <52B01411.6020202@redhat.com> Date: Tue, 17 Dec 2013 09:06:00 -0000 From: Andrew Haley User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.2.0 MIME-Version: 1.0 To: dw , gcc-help@gcc.gnu.org Subject: Re: immediate operands without dollar sign for inline asm References: <52AF8AD5.2080504@yahoo.com> In-Reply-To: <52AF8AD5.2080504@yahoo.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-IsSubscribed: yes X-SW-Source: 2013-12/txt/msg00117.txt.bz2 On 12/16/2013 11:20 PM, dw wrote: > > On 12/16/2013 3:29 AM, Luchezar Belev wrote: >> Hello, >> Sometimes one needs to pass an immediate operand to asm statement that >> should not be prefixed with dollar sign (e.g. for doing custom things >> with assembly directives). >> >> After much search in the internet i managed to find the way to do it: >> when the operand is used in the assembly string, it must have the 'a' >> modifier. (e.g. ".equ name, %a0" instead of ".equ name, %0". >> >> My question is: why is this feature not mentioned anywhere in the GCC >> documentation and is so extremely hard to find info about? Does this >> mean that it is planned for removal or deprecation? Can one rely on >> it's presence in future GCC versions? >> (I think it is extremely useful for some specific tasks, please don't >> remove it!) >> > I also found the gcc docs for asm to be very limited, so I have been > re-writing them. > > For example, I have documented a number of the modifiers (see > www.LimeGreenSocks.com/gcc/Extended-Asm.html#i386Operandmodifiers). > Because of concerns expressed in some of gcc's bug reports re asm, I > have tried to limit the number of modifiers I doc to those I believe are > essential, and commonly useful. I haven't doc'ed %a. Perhaps %c will > do what you need? > > I haven't had much (actually any) response from the gcc doc people about > this effort. I responded. I reviewed part of it, and there were significant technical inaccuracies that had to be addressed before the changes were considered for inclusion. > But perhaps someday these updates can be rolled back into the docs. Perhaps. What is your copyright assignment status? Andrew.