From patchwork Fri Oct 25 17:02:46 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Glisse X-Patchwork-Id: 286178 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from sourceware.org (server1.sourceware.org [209.132.180.131]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 0482F2C0089 for ; Sat, 26 Oct 2013 04:02:58 +1100 (EST) DomainKey-Signature: a=rsa-sha1; c=nofws; d=gcc.gnu.org; h=list-id :list-unsubscribe:list-archive:list-post:list-help:sender:date :from:to:cc:subject:in-reply-to:message-id:references :mime-version:content-type; q=dns; s=default; b=I3ipuK1A4mpgcCvq r/cJRgJLYP5T5LE4m/1nj8+l67CN128fqSQgGc2pe9j12Cn09Qd2CpA/RkNOSOPf NWcgzIR4yI+CynS6tuZ+QCmjWBeysvwQ+CN+qhy9raHje/L8WdAp/+6Dq5hm19X/ nbXUM1FMeORJ5THjkCFfOcH9Z48= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=gcc.gnu.org; h=list-id :list-unsubscribe:list-archive:list-post:list-help:sender:date :from:to:cc:subject:in-reply-to:message-id:references :mime-version:content-type; s=default; bh=7Ms+q+82RCxqlfUQ8vJxtw KcpDQ=; b=GBJXrbmNnPn1jETiegIyHSXcPyS4yO0RoibWG9uDPRl7EQwaP376IU 6MqBJmxaWnruh04N+muIba4/mmODSWHMEOPs8A1gctrTihNFq6FLzjY7sPRSfIWJ atP48qzGa1FsLIY80z+ve1Zn9mZWGJvfSwTaKoW+UdyY2t8gQOMcM= Received: (qmail 11892 invoked by alias); 25 Oct 2013 17:02:52 -0000 Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Delivered-To: mailing list gcc-patches@gcc.gnu.org Received: (qmail 11876 invoked by uid 89); 25 Oct 2013 17:02:51 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-4.1 required=5.0 tests=AWL, BAYES_00, RP_MATCHES_RCVD autolearn=ham version=3.3.2 X-HELO: mail2-relais-roc.national.inria.fr Received: from mail2-relais-roc.national.inria.fr (HELO mail2-relais-roc.national.inria.fr) (192.134.164.83) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (CAMELLIA256-SHA encrypted) ESMTPS; Fri, 25 Oct 2013 17:02:50 +0000 Received: from stedding.saclay.inria.fr ([193.55.250.194]) by mail2-relais-roc.national.inria.fr with ESMTP/TLS/DHE-RSA-AES128-SHA; 25 Oct 2013 19:02:48 +0200 Received: from glisse (helo=localhost) by stedding.saclay.inria.fr with local-esmtp (Exim 4.80) (envelope-from ) id 1VZkmc-0002ZJ-Of; Fri, 25 Oct 2013 19:02:46 +0200 Date: Fri, 25 Oct 2013 19:02:46 +0200 (CEST) From: Marc Glisse To: Richard Biener cc: Jeff Law , GCC Patches Subject: Re: Aliasing: look through pointer's def stmt In-Reply-To: Message-ID: References: <526A0269.8030407@redhat.com> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 On Fri, 25 Oct 2013, Richard Biener wrote: > you can followup with handling POINTER_PLUS_EXPR if you like. Like this? (bootstrap+testsuite on x86_64-unknown-linux-gnu) 2013-10-26 Marc Glisse gcc/ * tree-ssa-alias.c (ao_ref_init_from_ptr_and_size): Look for a POINTER_PLUS_EXPR in the defining statement. gcc/testsuite/ * gcc.dg/tree-ssa/alias-24.c: New file. Index: gcc/testsuite/gcc.dg/tree-ssa/alias-24.c =================================================================== --- gcc/testsuite/gcc.dg/tree-ssa/alias-24.c (revision 0) +++ gcc/testsuite/gcc.dg/tree-ssa/alias-24.c (working copy) @@ -0,0 +1,13 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -fdump-tree-optimized" } */ + +void f (const char *c, int *i) +{ + *i = 42; + __builtin_memcpy (i + 1, c, sizeof (int)); + if (*i != 42) __builtin_abort(); +} + +/* { dg-final { scan-tree-dump-not "abort" "optimized" } } */ +/* { dg-final { cleanup-tree-dump "optimized" } } */ + Property changes on: gcc/testsuite/gcc.dg/tree-ssa/alias-24.c ___________________________________________________________________ Added: svn:keywords ## -0,0 +1 ## +Author Date Id Revision URL \ No newline at end of property Added: svn:eol-style ## -0,0 +1 ## +native \ No newline at end of property Index: gcc/tree-ssa-alias.c =================================================================== --- gcc/tree-ssa-alias.c (revision 204071) +++ gcc/tree-ssa-alias.c (working copy) @@ -567,20 +567,28 @@ void ao_ref_init_from_ptr_and_size (ao_ref *ref, tree ptr, tree size) { HOST_WIDE_INT t1, t2; ref->ref = NULL_TREE; if (TREE_CODE (ptr) == SSA_NAME) { gimple stmt = SSA_NAME_DEF_STMT (ptr); if (gimple_assign_single_p (stmt) && gimple_assign_rhs_code (stmt) == ADDR_EXPR) ptr = gimple_assign_rhs1 (stmt); + else if (is_gimple_assign (stmt) + && gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR + && host_integerp (gimple_assign_rhs2 (stmt), 1)) + { + ao_ref_init_from_ptr_and_size (ref, gimple_assign_rhs1 (stmt), size); + ref->offset += 8 * TREE_INT_CST_LOW (gimple_assign_rhs2 (stmt)); + return; + } } if (TREE_CODE (ptr) == ADDR_EXPR) ref->base = get_ref_base_and_extent (TREE_OPERAND (ptr, 0), &ref->offset, &t1, &t2); else { ref->base = build2 (MEM_REF, char_type_node, ptr, null_pointer_node); ref->offset = 0;