From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 31696 invoked by alias); 18 May 2011 21:20:35 -0000 Received: (qmail 31689 invoked by uid 22791); 18 May 2011 21:20:34 -0000 X-SWARE-Spam-Status: No, hits=-2.0 required=5.0 tests=AWL,BAYES_00,T_RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Received: from nikam.ms.mff.cuni.cz (HELO nikam.ms.mff.cuni.cz) (195.113.20.16) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Wed, 18 May 2011 21:20:19 +0000 Received: from localhost (occam.kam.mff.cuni.cz [195.113.17.166]) by nikam.ms.mff.cuni.cz (Postfix) with ESMTP id 45F449AC835; Wed, 18 May 2011 23:20:18 +0200 (CEST) Received: by localhost (Postfix, from userid 29025) id 41437564111; Wed, 18 May 2011 23:20:18 +0200 (CEST) Date: Thu, 19 May 2011 05:33:00 -0000 From: Zdenek Dvorak To: Tom de Vries Cc: gcc-patches@gcc.gnu.org Subject: Re: [PATCH PR45098, 9/10] Cheap shift-add. Message-ID: <20110518212018.GA28543@kam.mff.cuni.cz> References: <4DD21F6E.4050308@codesourcery.com> <4DD221FC.7060303@codesourcery.com> <4DD4006E.406@codesourcery.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4DD4006E.406@codesourcery.com> User-Agent: Mutt/1.5.18 (2008-05-17) 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: 2011-05/txt/msg01343.txt.bz2 Hi, > + sa_cost = (TREE_CODE (expr) != MINUS_EXPR > + ? shiftadd_cost[speed][mode][m] > + : (mult == op1 > + ? shiftsub1_cost[speed][mode][m] > + : shiftsub0_cost[speed][mode][m])); > + res = new_cost (sa_cost, 0); > + res = add_costs (res, mult == op1 ? cost0 : cost1); just forgetting the cost of the other operand does not seem correct -- what if it contains some more complicated subexpression? Zdenek