From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 18687 invoked by alias); 23 Oct 2011 09:31:20 -0000 Received: (qmail 18674 invoked by uid 22791); 23 Oct 2011 09:31:19 -0000 X-SWARE-Spam-Status: No, hits=-2.3 required=5.0 tests=AWL,BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,RCVD_IN_DNSWL_LOW X-Spam-Check-By: sourceware.org Received: from mail-yw0-f47.google.com (HELO mail-yw0-f47.google.com) (209.85.213.47) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Sun, 23 Oct 2011 09:31:05 +0000 Received: by ywf9 with SMTP id 9so2937101ywf.20 for ; Sun, 23 Oct 2011 02:31:04 -0700 (PDT) MIME-Version: 1.0 Received: by 10.182.13.6 with SMTP id d6mr2408296obc.11.1319362264386; Sun, 23 Oct 2011 02:31:04 -0700 (PDT) Received: by 10.182.12.202 with HTTP; Sun, 23 Oct 2011 02:31:04 -0700 (PDT) In-Reply-To: References: <7d649d85-73fa-4c37-bd6e-d3527500196b@zmail14.collab.prod.int.phx2.redhat.com> Date: Sun, 23 Oct 2011 10:11:00 -0000 Message-ID: Subject: Re: [patch tree-optimization]: allow branch-cost optimization for truth-and/or on mode-expanded simple boolean-operands From: Richard Guenther To: Kai Tietz Cc: Kai Tietz , gcc-patches@gcc.gnu.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable X-IsSubscribed: yes 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: 2011-10/txt/msg02087.txt.bz2 On Fri, Oct 21, 2011 at 2:19 PM, Kai Tietz wrote: > 2011/10/21 Richard Guenther : >> On Thu, Oct 20, 2011 at 3:08 PM, Kai Tietz wrote: >>> Hello, >>> >>> this patch re-enables the branch-cost optimization on simple boolean-ty= ped operands, which are casted to a wider integral type. =A0This happens du= e casts from >>> boolean-types are preserved, but FE might expands simple-expression to = wider mode. >>> >>> I added two tests for already working branch-cost optimization for IA-a= rchitecture and >>> two for explicit checking for boolean-type. >>> >>> ChangeLog >>> >>> 2011-10-20 =A0Kai Tietz =A0 >>> >>> =A0 =A0 =A0 =A0* fold-const.c (simple_operand_p_2): Handle integral >>> =A0 =A0 =A0 =A0casts from boolean-operands. >>> >>> 2011-10-20 =A0Kai Tietz =A0 >>> >>> =A0 =A0 =A0 =A0* gcc.target/i386/branch-cost1.c: New test. >>> =A0 =A0 =A0 =A0* gcc.target/i386/branch-cost2.c: New test. >>> =A0 =A0 =A0 =A0* gcc.target/i386/branch-cost3.c: New test. >>> =A0 =A0 =A0 =A0* gcc.target/i386/branch-cost4.c: New test. >>> >>> Bootstrapped and regression tested on x86_64-unknown-linux-gnu for all = languages including Ada and Obj-C++. =A0Ok for apply? >>> >>> Regards, >>> Kai >>> >>> Index: gcc-head/gcc/testsuite/gcc.target/i386/branch-cost2.c >>> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D >>> --- /dev/null >>> +++ gcc-head/gcc/testsuite/gcc.target/i386/branch-cost2.c >>> @@ -0,0 +1,16 @@ >>> +/* { dg-do compile } */ >>> +/* { dg-options "-O2 -fdump-tree-gimple -mbranch-cost=3D2" } */ >>> + >>> +extern int doo (void); >>> + >>> +int >>> +foo (int a, int b) >>> +{ >>> + =A0if (a && b) >>> + =A0 return doo (); >>> + =A0return 0; >>> +} >>> + >>> +/* { dg-final { scan-tree-dump-times "if " 1 "gimple" } } */ >>> +/* { dg-final { scan-tree-dump-times " & " 1 "gimple" } } */ >>> +/* { dg-final { cleanup-tree-dump "gimple" } } */ >>> Index: gcc-head/gcc/testsuite/gcc.target/i386/branch-cost3.c >>> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D >>> --- /dev/null >>> +++ gcc-head/gcc/testsuite/gcc.target/i386/branch-cost3.c >>> @@ -0,0 +1,16 @@ >>> +/* { dg-do compile } */ >>> +/* { dg-options "-O2 -fdump-tree-gimple -mbranch-cost=3D2" } */ >>> + >>> +extern int doo (void); >>> + >>> +int >>> +foo (_Bool a, _Bool b) >>> +{ >>> + =A0if (a && b) >>> + =A0 return doo (); >>> + =A0return 0; >>> +} >>> + >>> +/* { dg-final { scan-tree-dump-times "if " 1 "gimple" } } */ >>> +/* { dg-final { scan-tree-dump-times " & " 1 "gimple" } } */ >>> +/* { dg-final { cleanup-tree-dump "gimple" } } */ >>> Index: gcc-head/gcc/testsuite/gcc.target/i386/branch-cost4.c >>> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D >>> --- /dev/null >>> +++ gcc-head/gcc/testsuite/gcc.target/i386/branch-cost4.c >>> @@ -0,0 +1,16 @@ >>> +/* { dg-do compile } */ >>> +/* { dg-options "-O2 -fdump-tree-gimple -mbranch-cost=3D0" } */ >>> + >>> +extern int doo (void); >>> + >>> +int >>> +foo (_Bool a, _Bool b) >>> +{ >>> + =A0if (a && b) >>> + =A0 return doo (); >>> + =A0return 0; >>> +} >>> + >>> +/* { dg-final { scan-tree-dump-times "if " 2 "gimple" } } */ >>> +/* { dg-final { scan-tree-dump-not " & " "gimple" } } */ >>> +/* { dg-final { cleanup-tree-dump "gimple" } } */ >>> Index: gcc-head/gcc/fold-const.c >>> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D >>> --- gcc-head.orig/gcc/fold-const.c >>> +++ gcc-head/gcc/fold-const.c >>> @@ -3706,6 +3706,19 @@ simple_operand_p_2 (tree exp) >>> =A0 /* Strip any conversions that don't change the machine mode. =A0*/ >>> =A0 STRIP_NOPS (exp); >>> >>> + =A0/* Handle integral widening casts from boolean-typed >>> + =A0 =A0 expressions as simple. =A0This happens due casts from >>> + =A0 =A0 boolean-types are preserved, but FE might expands >>> + =A0 =A0 simple-expression to wider mode. =A0*/ >>> + =A0if (INTEGRAL_TYPE_P (TREE_TYPE (exp)) >>> + =A0 =A0 =A0&& CONVERT_EXPR_P (exp) >>> + =A0 =A0 =A0&& TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) >>> + =A0 =A0 =A0 =A0=3D=3D BOOLEAN_TYPE) >>> + =A0 =A0{ >>> + =A0 =A0 =A0exp =3D TREE_OPERAND (exp, 0); >>> + =A0 =A0 =A0STRIP_NOPS (exp); >>> + =A0 =A0} >>> + >> >> Huh, well. =A0I think the above is just too special and you instead shou= ld >> replace the existing STRIP_NOPS by >> >> while (CONVERT_EXPR_P (exp)) >> =A0exp =3D TREE_OPERAND (exp, 0); >> >> with a comment that conversions are considered simple. >> >> Ok with that change, if it bootstraps & tests ok. >> >> Richard. > > Ok, bootstrapped and regression-tested on x86_64-unknown-linux-gnu and > applied to trunk with modifying as you suggested. > > One question I have about handling of TRUTH-binaries in general in > fold-const.c. =A0Why aren't we enforcing already here in fold_binary for > those operations, that operands get boolean-type? =A0I see here some > advantages of C-AST folding. =A0I've tested it and saw that even later > in SSA-passes we get slightly better results on that. Because we do not want to mess with the Frontends AST. Richard. > Regards, > Kai >