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[209.132.180.131]) by mx.google.com with ESMTPS id g12si23725555pla.142.2016.12.07.03.35.09 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 07 Dec 2016 03:35:09 -0800 (PST) Received-SPF: pass (google.com: domain of gcc-patches-return-443670-patch=linaro.org@gcc.gnu.org designates 209.132.180.131 as permitted sender) client-ip=209.132.180.131; Authentication-Results: mx.google.com; dkim=pass header.i=@gcc.gnu.org; spf=pass (google.com: domain of gcc-patches-return-443670-patch=linaro.org@gcc.gnu.org designates 209.132.180.131 as permitted sender) smtp.mailfrom=gcc-patches-return-443670-patch=linaro.org@gcc.gnu.org; dmarc=fail (p=NONE dis=NONE) header.from=linaro.org DomainKey-Signature: a=rsa-sha1; c=nofws; d=gcc.gnu.org; h=list-id :list-unsubscribe:list-archive:list-post:list-help:sender :mime-version:in-reply-to:references:from:date:message-id :subject:to:cc:content-type; q=dns; s=default; b=lflAyNR9KjqP4F4 EIzIthdzzldZO/Ah9dDfV9HB7J7ySsiPX0t3PBG983DvDL9vJSsgaoncfCG6f1h8 kmwLuJo+QRYsIYZhvlhj4rURtzpq3j9gZSfzkBuLL1ffajPvaLh34kqP40Xfv+h0 NAMIg/2+ivbOvjJw+OxYTxPuLNsk= 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 :mime-version:in-reply-to:references:from:date:message-id :subject:to:cc:content-type; s=default; bh=iu/TaVntl+KlXSAkzID1k 3U5qz8=; b=cV8tYf2XHaReqtXeACtbit8esUovHHahT8wGXqjbYV9Bi5xn18b85 vlKARoWHFKUhyb4XVj7b3h44DNuuTm8F533dowcX45y1IgT+tt+461uCyexdeGKs MO30M7eWMjLNu25Lrb3XnB6U+OXPXVOyrqJu++uG3+6bS3gaTG9MYE= Received: (qmail 4067 invoked by alias); 7 Dec 2016 11:33:00 -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 3651 invoked by uid 89); 7 Dec 2016 11:32:59 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.9 required=5.0 tests=AWL, BAYES_00, RCVD_IN_DNSWL_NONE, SPF_PASS autolearn=ham version=3.3.2 spammy=H*Ad:U*rguenther X-HELO: mail-io0-f172.google.com Received: from mail-io0-f172.google.com (HELO mail-io0-f172.google.com) (209.85.223.172) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Wed, 07 Dec 2016 11:32:49 +0000 Received: by mail-io0-f172.google.com with SMTP id c21so650451893ioj.1 for ; Wed, 07 Dec 2016 03:32:49 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=y/u0dZ4TqPqY0V3cSPbfLSTz1LVuolYniud+naHZeY0=; b=M+zMdHLrkqOw5CK7EOrAoIFwIvz4bzYcalxJN9kOxQXPu0JcsXfGRarCzoixEfJnLA /88ZkfsU05ZHC8+ZgcRHwE1xUO6AtsDJUTwsnQcH1gy7K7WUTIGfYDQ+HMQjOvZ4Hii6 yaIlQ1E+NOnxJrDo090pz/rcMb6pQYukoVZOCLSeq7EOZx7tbkFLVQHWWQjIgZV/bjB3 WEAMTZ52Gg+DSW90OHUTUi9QggOFWWmH+2Qr6LPTnnpT+5tokPYDvznubNP+BkP/Q4QN E92VsH8IuMv2X57wnBa9uyW4PEH/Pb1bR9RE4+KpRuJJgF9bFJqwW5zeGc7EbZ8yAQJy UP4w== X-Gm-Message-State: AKaTC01b+Yucf0EtMxZ0aRnSuMxriuY9JsuCLzAnXOV+7TwUudUz3fM8RqQijsDEMnN1SBYfZCYqd9NQr5LvMU4R X-Received: by 10.107.3.168 with SMTP id e40mr55013236ioi.89.1481110367366; Wed, 07 Dec 2016 03:32:47 -0800 (PST) MIME-Version: 1.0 Received: by 10.107.47.92 with HTTP; Wed, 7 Dec 2016 03:32:46 -0800 (PST) In-Reply-To: <20161205181742.GS3541@tucnak.redhat.com> References: <20161205181742.GS3541@tucnak.redhat.com> From: Prathamesh Kulkarni Date: Wed, 7 Dec 2016 17:02:46 +0530 Message-ID: Subject: Re: Fold strstr (s, t) eq/ne s to strcmp (s, t) eq/ne 0 if strlen (t) is known To: Jakub Jelinek Cc: gcc Patches , Richard Biener X-IsSubscribed: yes On 5 December 2016 at 23:47, Jakub Jelinek wrote: > On Mon, Dec 05, 2016 at 11:32:15PM +0530, Prathamesh Kulkarni wrote: >> So I had to check if SSA_NAME_DEF_STMT (rhs2) was call to strstr >> rather than rhs1. > > Then you need to test both whether it is strstr (s, t) == s or > s == strstr (s, t). > >> + gassign *ga = gimple_build_assign (lhs, code, >> + strcmp_lhs, zero); > > The formatting is wrong here. > >> + gsi_replace (&gsi, ga, false); >> + } >> + } >> + } >> + } >> + } >> + } >> else if (TREE_CODE (lhs) != SSA_NAME && !TREE_SIDE_EFFECTS (lhs)) >> { >> tree type = TREE_TYPE (lhs); >> @@ -2505,7 +2554,7 @@ const pass_data pass_data_strlen = >> 0, /* properties_provided */ >> 0, /* properties_destroyed */ >> 0, /* todo_flags_start */ >> - 0, /* todo_flags_finish */ >> + TODO_update_ssa, /* todo_flags_finish */ > > No, please don't. Just make sure to build proper SSA right away. Hi, Thanks for the suggestions, I have tried to modify the patch accordingly. Does this version look OK ? Bootstrap+tested on x86_64-unknown-linux-gnu with --enable-languages=all,ada Cross tested on arm*-*-*, aarch64*-*-*. Thanks, Prathamesh > > Jakub 2016-12-07 Prathamesh Kulkarni * tree-ssa-strlen.c (strlen_optimize_stmt): Fold strstr(s, t) == s to memcmp (s, t, strlen (t)) == 0. Include tree-into-ssa.h. testsuite/ * gcc.dg/strlenopt-30.c: New test-case. diff --git a/gcc/testsuite/gcc.dg/strlenopt-30.c b/gcc/testsuite/gcc.dg/strlenopt-30.c new file mode 100644 index 0000000..603e23c --- /dev/null +++ b/gcc/testsuite/gcc.dg/strlenopt-30.c @@ -0,0 +1,42 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -fdump-tree-strlen" } */ + +__attribute__((no_icf)) +_Bool f1(char *s) +{ + return __builtin_strstr (s, "hello") == s; +} + +__attribute__((no_icf)) +_Bool f2(char *s) +{ + return s == __builtin_strstr (s, "hello"); +} + +__attribute__((no_icf)) +_Bool f3(char *s) +{ + return s != __builtin_strstr (s, "hello"); +} + +__attribute__((no_icf)) +_Bool f4(char *s, char *t) +{ + return __builtin_strstr (s, t) == s; +} + +/* Do not perform transform in this case, since + t1 doesn't have single use. */ + +__attribute__((no_icf)) +_Bool f5(char *s, char *t) +{ + void foo(char *); + + char *t1 = __builtin_strstr (s, t); + foo (t1); + return (t1 == s); +} + +/* { dg-final { scan-tree-dump-times "__builtin_memcmp" 4 "strlen" } } */ +/* { dg-final { scan-tree-dump-times "__builtin_strlen" 1 "strlen" } } */ diff --git a/gcc/tree-ssa-strlen.c b/gcc/tree-ssa-strlen.c index 339812e..b7f4cee 100644 --- a/gcc/tree-ssa-strlen.c +++ b/gcc/tree-ssa-strlen.c @@ -45,6 +45,7 @@ along with GCC; see the file COPYING3. If not see #include "ipa-chkp.h" #include "tree-hash-traits.h" #include "builtins.h" +#include "tree-into-ssa.h" /* A vector indexed by SSA_NAME_VERSION. 0 means unknown, positive value is an index into strinfo vector, negative value stands for @@ -2302,7 +2303,94 @@ strlen_optimize_stmt (gimple_stmt_iterator *gsi) else if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR) handle_pointer_plus (gsi); } - else if (TREE_CODE (lhs) != SSA_NAME && !TREE_SIDE_EFFECTS (lhs)) + + /* Fold strstr (s, t) == s to memcmp (s, t, strlen (t)) == 0. + if var holding return value of strstr has single use. */ + + else if (TREE_CODE (lhs) == SSA_NAME && INTEGRAL_TYPE_P (TREE_TYPE (lhs))) + { + enum tree_code code = gimple_assign_rhs_code (stmt); + if (code == EQ_EXPR || code == NE_EXPR) + { + tree rhs1 = gimple_assign_rhs1 (stmt); + tree rhs2 = gimple_assign_rhs2 (stmt); + if (TREE_CODE (rhs1) == SSA_NAME + && TREE_CODE (rhs2) == SSA_NAME) + { + gcall *call_stmt = dyn_cast (SSA_NAME_DEF_STMT (rhs1)); + if (!call_stmt) + { + call_stmt = dyn_cast (SSA_NAME_DEF_STMT (rhs2)); + tree tmp = rhs1; + rhs1 = rhs2; + rhs2 = tmp; + } + + tree call_lhs; + if (call_stmt + && gimple_call_builtin_p (call_stmt, BUILT_IN_STRSTR) + && (call_lhs = gimple_call_lhs (call_stmt)) + && has_single_use (call_lhs)) + { + tree arg0 = gimple_call_arg (call_stmt, 0); + if (operand_equal_p (arg0, rhs2, 0)) + { + tree arg1 = gimple_call_arg (call_stmt, 1); + tree arg1_len = NULL_TREE; + int idx = get_stridx (arg1); + + if (idx) + { + if (idx < 0) + arg1_len = build_int_cst (size_type_node, + ~idx); + else + { + strinfo *si = get_strinfo (idx); + if (si) + arg1_len = get_string_length (si); + } + } + + if (arg1_len == NULL_TREE) + { + gimple_stmt_iterator gsi; + tree strlen_decl; + gimple *strlen_call; + + strlen_decl = builtin_decl_explicit (BUILT_IN_STRLEN); + strlen_call = gimple_build_call (strlen_decl, 1, + arg1); + arg1_len = make_ssa_name (size_type_node); + gimple_call_set_lhs (strlen_call, arg1_len); + update_stmt (strlen_call); + gsi = gsi_for_stmt (call_stmt); + gsi_insert_before (&gsi, strlen_call, GSI_SAME_STMT); + } + + gimple_stmt_iterator gsi = gsi_for_stmt (call_stmt); + tree memcmp_decl = builtin_decl_explicit (BUILT_IN_MEMCMP); + gcall *memcmp_call + = gimple_build_call (memcmp_decl, 3, arg0, arg1, + arg1_len); + tree memcmp_lhs = make_ssa_name (integer_type_node); + gimple_call_set_lhs (memcmp_call, memcmp_lhs); + update_stmt (memcmp_call); + gsi_remove (&gsi, true); + gsi_insert_before (&gsi, memcmp_call, GSI_SAME_STMT); + + gsi = gsi_for_stmt (stmt); + tree zero = build_zero_cst (TREE_TYPE (memcmp_lhs)); + gassign *ga = gimple_build_assign (lhs, code, + memcmp_lhs, zero); + gsi_replace (&gsi, ga, false); + update_ssa (TODO_update_ssa); + } + } + } + } + } + else if (TREE_CODE (lhs) != SSA_NAME && !TREE_SIDE_EFFECTS (lhs)) { tree type = TREE_TYPE (lhs); if (TREE_CODE (type) == ARRAY_TYPE)