From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 26243 invoked by alias); 17 Jul 2015 15:47:51 -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 26234 invoked by uid 89); 17 Jul 2015 15:47:50 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-3.7 required=5.0 tests=AWL,BAYES_00,RP_MATCHES_RCVD,SPF_PASS autolearn=ham version=3.3.2 X-HELO: mx2.suse.de Received: from cantor2.suse.de (HELO mx2.suse.de) (195.135.220.15) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (CAMELLIA256-SHA encrypted) ESMTPS; Fri, 17 Jul 2015 15:47:49 +0000 Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 412FAAC1D; Fri, 17 Jul 2015 15:47:46 +0000 (UTC) User-Agent: K-9 Mail for Android In-Reply-To: <20150717152321.GM5101@redhat.com> References: <20150717102846.GL5101@redhat.com> <39B860F0-62C5-4662-B09D-1EC1EF8BE496@suse.de> <20150717152321.GM5101@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Subject: Re: [PATCH] Move A - (A & B) -> ~B & A From: Richard Biener Date: Fri, 17 Jul 2015 16:01:00 -0000 To: Marek Polacek CC: GCC Patches Message-ID: <2B70B256-3697-4944-B913-FD1DE8823365@suse.de> X-SW-Source: 2015-07/txt/msg01545.txt.bz2 On July 17, 2015 5:23:21 PM GMT+02:00, Marek Polacek wrote: >On Fri, Jul 17, 2015 at 02:23:50PM +0200, Richard Biener wrote: >> >+/* Fold A - (A & B) into ~B & A. */ >> >+(simplify >> >+ (minus (convert? @0) (convert? (bit_and:c @0 @1))) >> >> I think you want :s on the bit_and and its convert? > >Ok, I keep forgetting about this :(. > >> Are you sure you don't need to check for a nop conversion here? > >I thought I didn't need it here, and couldn't find a testcase which >would break without tree_nop_conversion_p checks, but that doesn't mean >much. So for extra safety I put the checks there. > >Bootstrapped/regtested on x86_64-linux, ok for trunk? OK Thanks Richard >2015-07-17 Marek Polacek > > * fold-const.c (fold_binary_loc): Move A - (A & B) into ~B & A ... > * match.pd: ... here. > > * gcc.dg/fold-minus-7.c: New test. > >diff --git gcc/fold-const.c gcc/fold-const.c >index 93dd29d..fa321f4 100644 >--- gcc/fold-const.c >+++ gcc/fold-const.c >@@ -9777,30 +9777,6 @@ fold_binary_loc (location_t loc, > > if (! FLOAT_TYPE_P (type)) > { >- /* Fold A - (A & B) into ~B & A. */ >- if (!TREE_SIDE_EFFECTS (arg0) >- && TREE_CODE (arg1) == BIT_AND_EXPR) >- { >- if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)) >- { >- tree arg10 = fold_convert_loc (loc, type, >- TREE_OPERAND (arg1, 0)); >- return fold_build2_loc (loc, BIT_AND_EXPR, type, >- fold_build1_loc (loc, BIT_NOT_EXPR, >- type, arg10), >- fold_convert_loc (loc, type, arg0)); >- } >- if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)) >- { >- tree arg11 = fold_convert_loc (loc, >- type, TREE_OPERAND (arg1, 1)); >- return fold_build2_loc (loc, BIT_AND_EXPR, type, >- fold_build1_loc (loc, BIT_NOT_EXPR, >- type, arg11), >- fold_convert_loc (loc, type, arg0)); >- } >- } >- > /* Fold (A & ~B) - (A & B) into (A ^ B) - B, where B is > any power of 2 minus 1. */ > if (TREE_CODE (arg0) == BIT_AND_EXPR >diff --git gcc/match.pd gcc/match.pd >index c335ada..700a692 100644 >--- gcc/match.pd >+++ gcc/match.pd >@@ -662,6 +662,12 @@ along with GCC; see the file COPYING3. If not see > (bit_ior:c (bit_and:cs @0 (bit_not @2)) (bit_and:cs @1 @2)) > (bit_xor (bit_and (bit_xor @0 @1) @2) @0)) > >+/* Fold A - (A & B) into ~B & A. */ >+(simplify >+ (minus (convert? @0) (convert?:s (bit_and:cs @0 @1))) >+ (if (tree_nop_conversion_p (type, TREE_TYPE (@0)) >+ && tree_nop_conversion_p (type, TREE_TYPE (@1))) >+ (convert (bit_and (bit_not @1) @0)))) > > /* Associate (p +p off1) +p off2 as (p +p (off1 + off2)). */ > (simplify >diff --git gcc/testsuite/gcc.dg/fold-minus-7.c >gcc/testsuite/gcc.dg/fold-minus-7.c >index e69de29..7a49faa 100644 >--- gcc/testsuite/gcc.dg/fold-minus-7.c >+++ gcc/testsuite/gcc.dg/fold-minus-7.c >@@ -0,0 +1,36 @@ >+/* { dg-do compile } */ >+/* { dg-options "-O -fdump-tree-cddce1" } */ >+ >+int >+f1 (int a, int b) >+{ >+ int tem = a & b; >+ return a - tem; >+} >+ >+int >+f2 (int a, int b) >+{ >+ int tem = b & a; >+ return a - tem; >+} >+ >+int >+f3 (unsigned int a, int b) >+{ >+ return a - (a & b); >+} >+ >+int >+f4 (int a, unsigned int b) >+{ >+ return a - (a & b); >+} >+ >+int >+f5 (int a, int b) >+{ >+ return a - (unsigned) (b & a); >+} >+ >+/* { dg-final { scan-tree-dump-not " - " "cddce1" } } */ > > Marek