From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 19008 invoked by alias); 23 Aug 2011 09:53:32 -0000 Received: (qmail 18999 invoked by uid 22791); 23 Aug 2011 09:53:32 -0000 X-SWARE-Spam-Status: No, hits=-6.8 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_HI,RP_MATCHES_RCVD,SPF_HELO_PASS X-Spam-Check-By: sourceware.org Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Tue, 23 Aug 2011 09:53:15 +0000 Received: from int-mx01.intmail.prod.int.phx2.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id p7N9qjDI019146 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Tue, 23 Aug 2011 05:52:46 -0400 Received: from tyan-ft48-01.lab.bos.redhat.com (tyan-ft48-01.lab.bos.redhat.com [10.16.42.4]) by int-mx01.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id p7N9qif9019168 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Tue, 23 Aug 2011 05:52:45 -0400 Received: from tyan-ft48-01.lab.bos.redhat.com (localhost.localdomain [127.0.0.1]) by tyan-ft48-01.lab.bos.redhat.com (8.14.4/8.14.4) with ESMTP id p7N9qiJr009849; Tue, 23 Aug 2011 11:52:44 +0200 Received: (from jakub@localhost) by tyan-ft48-01.lab.bos.redhat.com (8.14.4/8.14.4/Submit) id p7N9qhqb009847; Tue, 23 Aug 2011 11:52:43 +0200 Date: Tue, 23 Aug 2011 10:25:00 -0000 From: Jakub Jelinek To: Bernd Schmidt Cc: Eric Botcazou , Richard Sandiford , Richard Henderson , GCC Patches Subject: Re: Add __builtin_clrsb, similar to clz/ctz Message-ID: <20110823095243.GD2687@tyan-ft48-01.lab.bos.redhat.com> Reply-To: Jakub Jelinek References: <4DF9FA9A.8040505@codesourcery.com> <4DFA2E85.2030601@redhat.com> <4DFFA1AE.7070405@codesourcery.com> <20110823090549.GC2687@tyan-ft48-01.lab.bos.redhat.com> <4E53744B.6040502@codesourcery.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4E53744B.6040502@codesourcery.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-IsSubscribed: yes Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org X-SW-Source: 2011-08/txt/msg01859.txt.bz2 On Tue, Aug 23, 2011 at 11:35:07AM +0200, Bernd Schmidt wrote: > > cse_process_notes_1 > > perhaps could be changed for VOIDmode new_rtx to try to > > simplify_replace_rtx it... > > Is this where the problem came from? Sounds like it's worth a try. In this case, yes. But there are many other places all around the compiler that need to disallow unary op with VOIDmode operand. In cse.c alone e.g. fold_rtx (twice), in combine.c e.g. in do_SUBST, subst, etc. Do we want to special case all those 7 unary ops there too? Is it really worth it to save one subreg or truncate in the md patterns for rarely used rtxes? > Wasn't Richard S. working on a patch to give constants modes? I don't think this is achievable for 4.7... Jakub