From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 20514 invoked by alias); 7 Jun 2013 08:30:45 -0000 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 Received: (qmail 20504 invoked by uid 89); 7 Jun 2013 08:30:44 -0000 X-Spam-SWARE-Status: No, score=-3.5 required=5.0 tests=AWL,BAYES_00,FREEMAIL_FROM,KHOP_THREADED,RCVD_IN_DNSWL_LOW,RCVD_IN_HOSTKARMA_YE,SPF_PASS autolearn=ham version=3.3.1 Received: from mail-ob0-f169.google.com (HELO mail-ob0-f169.google.com) (209.85.214.169) by sourceware.org (qpsmtpd/0.84/v0.84-167-ge50287c) with ESMTP; Fri, 07 Jun 2013 08:30:43 +0000 Received: by mail-ob0-f169.google.com with SMTP id up14so6096937obb.28 for ; Fri, 07 Jun 2013 01:30:41 -0700 (PDT) X-Received: by 10.182.148.136 with SMTP id ts8mr4061969obb.36.1370593841867; Fri, 07 Jun 2013 01:30:41 -0700 (PDT) MIME-Version: 1.0 Received: by 10.182.125.225 with HTTP; Fri, 7 Jun 2013 01:30:01 -0700 (PDT) In-Reply-To: <51B178BA.1000802@redhat.com> References: <51B178BA.1000802@redhat.com> From: Steven Bosscher Date: Fri, 07 Jun 2013 08:30:00 -0000 Message-ID: Subject: Re: Improve uncprop and coalescing To: Jeff Law Cc: gcc-patches Content-Type: text/plain; charset=ISO-8859-1 X-SW-Source: 2013-06/txt/msg00380.txt.bz2 On Fri, Jun 7, 2013 at 8:07 AM, Jeff Law wrote: > Rather than using strict pointer equality, we can do better by looking at > TYPE_CANONICAL when it's available. Thus objects of the following two types > (T1 & T2) become candidates for coalescing if they are tied together by a > copy or PHI node. > > typedef int t1; > typedef int t2; > > > This typically eliminates necessary copies and constant initializations, > which is good. Hmm... Can't you use types_compatible_p? Ciao! Steven