From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 25625 invoked by alias); 8 Apr 2008 18:33:44 -0000 Received: (qmail 25574 invoked by uid 22791); 8 Apr 2008 18:33:27 -0000 X-Spam-Check-By: sourceware.org Received: from fg-out-1718.google.com (HELO fg-out-1718.google.com) (72.14.220.154) by sourceware.org (qpsmtpd/0.31) with ESMTP; Tue, 08 Apr 2008 18:33:09 +0000 Received: by fg-out-1718.google.com with SMTP id d23so1618491fga.28 for ; Tue, 08 Apr 2008 11:33:06 -0700 (PDT) Received: by 10.86.26.11 with SMTP id 11mr5153880fgz.74.1207679586609; Tue, 08 Apr 2008 11:33:06 -0700 (PDT) Received: by 10.86.73.11 with HTTP; Tue, 8 Apr 2008 11:33:06 -0700 (PDT) Message-ID: <178adb870804081133t4b2a71c4j9f1f802bb02f075c@mail.gmail.com> Date: Tue, 08 Apr 2008 19:52:00 -0000 From: Omar To: "Jim Wilson" Subject: Re: Understanding Predicate and Constrains Cc: gcc-help@gcc.gnu.org In-Reply-To: <178adb870804081024n6c055d2boab4bed7750f5b16d@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <178adb870804071349p62932c37h3c67d236a12795b3@mail.gmail.com> <47FB974E.1070505@tuliptree.org> <178adb870804081024n6c055d2boab4bed7750f5b16d@mail.gmail.com> 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 X-SW-Source: 2008-04/txt/msg00107.txt.bz2 Jim, First, thanks a lot for your comments. > It current sources, you want to define a > $target/constraints.md file that has a (define_contraint "I" ...) pattern. I have been looking at other targets, and they seem to use the CONST_OK_FOR_LETTER_P macro for this purpose. Is the define_constraint equivalent to what the macro CONST_OK_FOR _LETTER_P used to stand for? I am trying to understand is define_constraint replaces this macro's functionality. Your comment confirms my suspicion: > Most gcc internals stuff like this is not well documented. > You just try it, and if it works fine, if > it doesn't, then change it. -Omar