From patchwork Thu Nov 11 19:41:14 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Siddhesh Poyarekar X-Patchwork-Id: 47498 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 03F27385BF86 for ; Thu, 11 Nov 2021 19:42:17 +0000 (GMT) X-Original-To: gcc-patches@gcc.gnu.org Delivered-To: gcc-patches@gcc.gnu.org Received: from bee.birch.relay.mailchannels.net (bee.birch.relay.mailchannels.net [23.83.209.14]) by sourceware.org (Postfix) with ESMTPS id AC92A3857C5D for ; Thu, 11 Nov 2021 19:41:31 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org AC92A3857C5D Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=gotplt.org Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=gotplt.org X-Sender-Id: dreamhost|x-authsender|siddhesh@gotplt.org Received: from relay.mailchannels.net (localhost [127.0.0.1]) by relay.mailchannels.net (Postfix) with ESMTP id 34F96781494; Thu, 11 Nov 2021 19:41:30 +0000 (UTC) Received: from pdx1-sub0-mail-a304.dreamhost.com (100-96-39-10.trex.outbound.svc.cluster.local [100.96.39.10]) (Authenticated sender: dreamhost) by relay.mailchannels.net (Postfix) with ESMTPA id A92E4780787; Thu, 11 Nov 2021 19:41:29 +0000 (UTC) X-Sender-Id: dreamhost|x-authsender|siddhesh@gotplt.org Received: from pdx1-sub0-mail-a304.dreamhost.com (pop.dreamhost.com [64.90.62.162]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384) by 100.96.39.10 (trex/6.4.3); Thu, 11 Nov 2021 19:41:30 +0000 X-MC-Relay: Neutral X-MailChannels-SenderId: dreamhost|x-authsender|siddhesh@gotplt.org X-MailChannels-Auth-Id: dreamhost X-Decisive-Whimsical: 506afaab35a2714a_1636659689936_178636315 X-MC-Loop-Signature: 1636659689936:1357271222 X-MC-Ingress-Time: 1636659689936 Received: from rhbox.redhat.com (unknown [1.186.121.107]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: siddhesh@gotplt.org) by pdx1-sub0-mail-a304.dreamhost.com (Postfix) with ESMTPSA id 4HqsXl6tNMz2Y; Thu, 11 Nov 2021 11:41:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; d=gotplt.org; s=gotplt.org; t=1636659689; bh=mWrnqL8m1bNFt4a0Gx6O9R/ZgWY=; h=From:To:Cc:Subject:Date:Content-Transfer-Encoding; b=VaEzlemd5imWRJ7PdA5h52AyU3sgyelnv668Cs3XI3hs82v+Xt+Rue7ogYfdVuEvI 5BqRgtInWaiDrgxqk8QYXjHm5xpgkocCKTCCXuSnqpb+2tQ1gVUgImnTJwzh8NjkeW vw6TzaR4ipUIYVXOoZK2sCScbeDDWKyYseD5kvrM= From: Siddhesh Poyarekar To: gcc-patches@gcc.gnu.org Subject: [PATCH 1/3] gimple-fold: Transform stp*cpy_chk to str*cpy directly Date: Fri, 12 Nov 2021 01:11:14 +0530 Message-Id: <20211111194116.1626980-2-siddhesh@gotplt.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20211111194116.1626980-1-siddhesh@gotplt.org> References: <20211111194116.1626980-1-siddhesh@gotplt.org> MIME-Version: 1.0 X-Spam-Status: No, score=-3038.0 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, RCVD_IN_BARRACUDACENTRAL, RCVD_IN_DNSWL_NONE, RCVD_IN_SBL, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: gcc-patches@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: gcc-patches-bounces+patchwork=sourceware.org@gcc.gnu.org Sender: "Gcc-patches" Avoid going through another folding cycle and use the ignore flag to directly transform BUILT_IN_STPCPY_CHK to BUILT_IN_STRCPY when set, likewise for BUILT_IN_STPNCPY_CHK to BUILT_IN_STPNCPY. Dump the transformation in dump_file so that we can verify in tests that the direct transformation actually happened. gcc/ChangeLog: * gimple-fold.c (gimple_fold_builtin_stxcpy_chk, gimple_fold_builtin_stxncpy_chk): Use BUILT_IN_STRNCPY if return value is not used. gcc/testsuite/ChangeLog: * gcc.dg/fold-stringops.c: New test. Signed-off-by: Siddhesh Poyarekar --- gcc/gimple-fold.c | 50 +++++++++++++++++-------- gcc/testsuite/gcc.dg/fold-stringops-1.c | 23 ++++++++++++ 2 files changed, 57 insertions(+), 16 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/fold-stringops-1.c diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c index 6e25a7c05db..92e15784803 100644 --- a/gcc/gimple-fold.c +++ b/gcc/gimple-fold.c @@ -3088,6 +3088,19 @@ gimple_fold_builtin_memory_chk (gimple_stmt_iterator *gsi, return true; } +static void +dump_transformation (gimple *from, gimple *to) +{ + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fprintf (dump_file, "transformed "); + print_generic_expr (dump_file, gimple_call_fn (from), dump_flags); + fprintf (dump_file, " to "); + print_generic_expr (dump_file, gimple_call_fn (to), dump_flags); + fprintf (dump_file, "\n"); + } +} + /* Fold a call to the __st[rp]cpy_chk builtin. DEST, SRC, and SIZE are the arguments to the call. IGNORE is true if return value can be ignored. FCODE is the BUILT_IN_* @@ -3184,12 +3197,13 @@ gimple_fold_builtin_stxcpy_chk (gimple_stmt_iterator *gsi, } /* If __builtin_st{r,p}cpy_chk is used, assume st{r,p}cpy is available. */ - fn = builtin_decl_explicit (fcode == BUILT_IN_STPCPY_CHK + fn = builtin_decl_explicit (fcode == BUILT_IN_STPCPY_CHK && !ignore ? BUILT_IN_STPCPY : BUILT_IN_STRCPY); if (!fn) return false; gimple *repl = gimple_build_call (fn, 2, dest, src); + dump_transformation (stmt, repl); replace_call_with_call_and_fold (gsi, repl); return true; } @@ -3209,19 +3223,6 @@ gimple_fold_builtin_stxncpy_chk (gimple_stmt_iterator *gsi, bool ignore = gimple_call_lhs (stmt) == NULL_TREE; tree fn; - if (fcode == BUILT_IN_STPNCPY_CHK && ignore) - { - /* If return value of __stpncpy_chk is ignored, - optimize into __strncpy_chk. */ - fn = builtin_decl_explicit (BUILT_IN_STRNCPY_CHK); - if (fn) - { - gimple *repl = gimple_build_call (fn, 4, dest, src, len, size); - replace_call_with_call_and_fold (gsi, repl); - return true; - } - } - if (! tree_fits_uhwi_p (size)) return false; @@ -3234,7 +3235,23 @@ gimple_fold_builtin_stxncpy_chk (gimple_stmt_iterator *gsi, For MAXLEN only allow optimizing into non-_ocs function if SIZE is >= MAXLEN, never convert to __ocs_fail (). */ if (maxlen == NULL_TREE || ! tree_fits_uhwi_p (maxlen)) - return false; + { + if (fcode == BUILT_IN_STPNCPY_CHK && ignore) + { + /* If return value of __stpncpy_chk is ignored, + optimize into __strncpy_chk. */ + fn = builtin_decl_explicit (BUILT_IN_STRNCPY_CHK); + if (fn) + { + gimple *repl = gimple_build_call (fn, 4, dest, src, len, + size); + replace_call_with_call_and_fold (gsi, repl); + return true; + } + } + + return false; + } } else maxlen = len; @@ -3244,12 +3261,13 @@ gimple_fold_builtin_stxncpy_chk (gimple_stmt_iterator *gsi, } /* If __builtin_st{r,p}ncpy_chk is used, assume st{r,p}ncpy is available. */ - fn = builtin_decl_explicit (fcode == BUILT_IN_STPNCPY_CHK + fn = builtin_decl_explicit (fcode == BUILT_IN_STPNCPY_CHK && !ignore ? BUILT_IN_STPNCPY : BUILT_IN_STRNCPY); if (!fn) return false; gimple *repl = gimple_build_call (fn, 3, dest, src, len); + dump_transformation (stmt, repl); replace_call_with_call_and_fold (gsi, repl); return true; } diff --git a/gcc/testsuite/gcc.dg/fold-stringops-1.c b/gcc/testsuite/gcc.dg/fold-stringops-1.c new file mode 100644 index 00000000000..712dd369e7c --- /dev/null +++ b/gcc/testsuite/gcc.dg/fold-stringops-1.c @@ -0,0 +1,23 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -fdump-tree-lower-details" } */ + +char dst[2048]; + +char * +copy1 (const char *src, int cond) +{ + __builtin___stpncpy_chk (dst, src, 42, __builtin_object_size (dst, 0)); + + return dst; +} + +char * +copy2 (void) +{ + __builtin___stpcpy_chk (dst, "Hello world", __builtin_object_size (dst, 0)); + + return dst; +} +/* { dg-final { scan-tree-dump "transformed __builtin___stpncpy_chk to __builtin_strncpy" "lower" } } */ +/* { dg-final { scan-tree-dump "transformed __builtin___stpcpy_chk to __builtin_strcpy" "lower" } } */ +