From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 27077 invoked by alias); 18 May 2011 21:12:15 -0000 Received: (qmail 27068 invoked by uid 22791); 18 May 2011 21:12:14 -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 21:11:59 +0000 Received: from localhost (occam.kam.mff.cuni.cz [195.113.17.166]) by nikam.ms.mff.cuni.cz (Postfix) with ESMTP id 39C999AC182; Wed, 18 May 2011 23:11:58 +0200 (CEST) Received: by localhost (Postfix, from userid 29025) id 34BB2564111; Wed, 18 May 2011 23:11:58 +0200 (CEST) Date: Thu, 19 May 2011 04:45:00 -0000 From: Zdenek Dvorak To: Tom de Vries Cc: gcc-patches@gcc.gnu.org Subject: Re: [PATCH PR45098, 7/10] Nowrap limits iterations Message-ID: <20110518211157.GA19788@kam.mff.cuni.cz> References: <4DD21F6E.4050308@codesourcery.com> <4DD221CF.4040002@codesourcery.com> <4DD3FD79.2020804@codesourcery.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4DD3FD79.2020804@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/msg01341.txt.bz2 Hi, > This patch attemps to estimate the number of iterations of the loop based on > nonwrapping arithmetic in the loop body. > > 2011-05-05 Tom de Vries > > PR target/45098 > * tree-ssa-loop-ivopts.c (struct ivopts_data): Add fields > max_iterations_p and max_iterations. > (is_nonwrap_use, max_loop_iterations, set_max_iterations): New function. > (may_eliminate_iv): Use max_iterations_p and max_iterations. > (tree_ssa_iv_optimize_loop): Use set_max_iterations. what are the cases this handles better than the existing analysis of maximum numbers of iterations (estimate_numbers_of_iterations)? Would it be possible to add the handling of these cases to estimate_numbers_of_iterations, rather than doing it just for ivopts? Zdenek