From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 20958 invoked by alias); 13 Nov 2010 09:52:18 -0000 Received: (qmail 20948 invoked by uid 22791); 13 Nov 2010 09:52:17 -0000 X-SWARE-Spam-Status: No, hits=-2.0 required=5.0 tests=AWL,BAYES_00 X-Spam-Check-By: sourceware.org Received: from mel.act-europe.fr (HELO mel.act-europe.fr) (194.98.77.210) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Sat, 13 Nov 2010 09:52:03 +0000 Received: from localhost (localhost [127.0.0.1]) by filtered-smtp.eu.adacore.com (Postfix) with ESMTP id 46E67CB0264; Sat, 13 Nov 2010 10:52:01 +0100 (CET) Received: from mel.act-europe.fr ([127.0.0.1]) by localhost (smtp.eu.adacore.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id SRzGltV+6Do9; Sat, 13 Nov 2010 10:52:01 +0100 (CET) Received: from [192.168.1.2] (bon31-9-83-155-120-49.fbx.proxad.net [83.155.120.49]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mel.act-europe.fr (Postfix) with ESMTP id 300DDCB01D8; Sat, 13 Nov 2010 10:51:57 +0100 (CET) From: Eric Botcazou To: Tom de Vries Subject: Re: new sign/zero extension elimination pass Date: Sat, 13 Nov 2010 10:41:00 -0000 User-Agent: KMail/1.9.9 Cc: Paolo Bonzini , gcc-patches@gcc.gnu.org, Bernd Schmidt References: <4CBC698B.3080204@codesourcery.com> <4CDCF947.1030008@codesourcery.com> In-Reply-To: <4CDCF947.1030008@codesourcery.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <201011131050.53898.ebotcazou@adacore.com> 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: 2010-11/txt/msg01389.txt.bz2 > I profiled the pass on spec2000: > > -mabi=32 -mabi=64 > ee-pass (usr time): 0.70 1.16 > total (usr time): 919.30 879.26 > ee-pass (%): 0.08 0.13 > > The pass takes 0.13% or less of the total usr runtime. For how many hits? What are the numbers with --param ee-max-propagate=0? > Is it necessary to improve the runtime of this pass? I've already given my opinion about the implementation. The other passes in the compiler try hard not to rescan everything when a single bit changes; as currently written, yours doesn't. -- Eric Botcazou