From patchwork Wed Jun 7 00:17:05 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Pinski X-Patchwork-Id: 70684 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 181223857341 for ; Wed, 7 Jun 2023 00:18:07 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 181223857341 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1686097087; bh=cBeDqA/mmI04iQGt1fqg9mE+YfTg2bwf5pjSq7bbpEg=; h=To:CC:Subject:Date:List-Id:List-Unsubscribe:List-Archive: List-Post:List-Help:List-Subscribe:From:Reply-To:From; b=Z5IQynY/7vImfl8wUB3YKYpUuMuP3JaHm4GjadnNCmTEgl3Ol6zKobggI5cWCCRq6 KNo4nHbNiTK92YdxlUcNv2nv/QwAGzJKHf9hK99VgcZjpSJX7v/BlqQjq65/LmxOjJ r55mMQSRuFCxIHhM8tCm8g3JQeQ9N8Jpkp6iatGU= X-Original-To: gcc-patches@gcc.gnu.org Delivered-To: gcc-patches@gcc.gnu.org Received: from mx0b-0016f401.pphosted.com (mx0b-0016f401.pphosted.com [67.231.156.173]) by sourceware.org (Postfix) with ESMTPS id ACAE9385840D for ; Wed, 7 Jun 2023 00:17:17 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org ACAE9385840D Received: from pps.filterd (m0045851.ppops.net [127.0.0.1]) by mx0b-0016f401.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 356Lol8i001794 for ; Tue, 6 Jun 2023 17:17:17 -0700 Received: from dc5-exch01.marvell.com ([199.233.59.181]) by mx0b-0016f401.pphosted.com (PPS) with ESMTPS id 3r2a758ufg-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-SHA384 bits=256 verify=NOT) for ; Tue, 06 Jun 2023 17:17:17 -0700 Received: from DC5-EXCH01.marvell.com (10.69.176.38) by DC5-EXCH01.marvell.com (10.69.176.38) with Microsoft SMTP Server (TLS) id 15.0.1497.48; Tue, 6 Jun 2023 17:17:14 -0700 Received: from maili.marvell.com (10.69.176.80) by DC5-EXCH01.marvell.com (10.69.176.38) with Microsoft SMTP Server id 15.0.1497.48 via Frontend Transport; Tue, 6 Jun 2023 17:17:14 -0700 Received: from vpnclient.wrightpinski.org.com (unknown [10.69.242.187]) by maili.marvell.com (Postfix) with ESMTP id B09493F708C; Tue, 6 Jun 2023 17:17:14 -0700 (PDT) To: CC: Andrew Pinski Subject: [PATCH 1/2] Match: zero_one_valued_p should match 0 constants too Date: Tue, 6 Jun 2023 17:17:05 -0700 Message-ID: <20230607001706.3000011-1-apinski@marvell.com> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 X-Proofpoint-ORIG-GUID: yeSg7a1EImtb4ZlD14oXq3sA7gvtfCub X-Proofpoint-GUID: yeSg7a1EImtb4ZlD14oXq3sA7gvtfCub X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.254,Aquarius:18.0.957,Hydra:6.0.573,FMLib:17.11.176.26 definitions=2023-06-06_18,2023-06-06_02,2023-05-22_02 X-Spam-Status: No, score=-14.6 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, RCVD_IN_DNSWL_LOW, SPF_HELO_NONE, SPF_PASS, TXREP, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) 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: , X-Patchwork-Original-From: Andrew Pinski via Gcc-patches From: Andrew Pinski Reply-To: Andrew Pinski Errors-To: gcc-patches-bounces+patchwork=sourceware.org@gcc.gnu.org Sender: "Gcc-patches" While working on `bool0 ? bool1 : bool2` I noticed that zero_one_valued_p does not match on the constant zero as in that case tree_nonzero_bits will return 0 and that is different from 1. OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions. gcc/ChangeLog: * match.pd (zero_one_valued_p): Match 0 integer constant too. --- gcc/match.pd | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/gcc/match.pd b/gcc/match.pd index f9cbd757752..f97ff7ef760 100644 --- a/gcc/match.pd +++ b/gcc/match.pd @@ -1983,11 +1983,16 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) (bit_not (bit_not @0)) @0) +/* zero_one_valued_p will match when a value is known to be either + 0 or 1 including the constant 0. */ (match zero_one_valued_p @0 (if (INTEGRAL_TYPE_P (type) && tree_nonzero_bits (@0) == 1))) (match zero_one_valued_p truth_valued_p@0) +(match zero_one_valued_p + integer_zerop@0 + (if (INTEGRAL_TYPE_P (type)))) /* Transform { 0 or 1 } * { 0 or 1 } into { 0 or 1 } & { 0 or 1 }. */ (simplify From patchwork Wed Jun 7 00:17:06 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Pinski X-Patchwork-Id: 70685 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 3D6D0385696A for ; Wed, 7 Jun 2023 00:18:12 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 3D6D0385696A DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1686097092; bh=72twOotOCEVv9yY1lJitpMb/ZR3UXGYLA2DPjbiANpM=; h=To:CC:Subject:Date:In-Reply-To:References:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From:Reply-To:From; b=tWEwP1FYpz4BirXBpXLAYSP092yf0Pzke53snY+uLTD0eVrjnAc4JHUpL80FwObiw VP6ocPlygbCVY7vBlWq0DKgFTSYPEbgcTv4NVPndfdVUxQRO5oqH9Q/4/dtTJGq/Ni eZYqq4KAqeLkWgH9b1MBNj/pYsaCdUr31gDv0VCE= X-Original-To: gcc-patches@gcc.gnu.org Delivered-To: gcc-patches@gcc.gnu.org Received: from mx0b-0016f401.pphosted.com (mx0a-0016f401.pphosted.com [67.231.148.174]) by sourceware.org (Postfix) with ESMTPS id 7877A3858421 for ; Wed, 7 Jun 2023 00:17:19 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 7877A3858421 Received: from pps.filterd (m0045849.ppops.net [127.0.0.1]) by mx0a-0016f401.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 356K43BW024712 for ; Tue, 6 Jun 2023 17:17:18 -0700 Received: from dc5-exch01.marvell.com ([199.233.59.181]) by mx0a-0016f401.pphosted.com (PPS) with ESMTPS id 3r2a7bs2un-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-SHA384 bits=256 verify=NOT) for ; Tue, 06 Jun 2023 17:17:18 -0700 Received: from DC5-EXCH02.marvell.com (10.69.176.39) by DC5-EXCH01.marvell.com (10.69.176.38) with Microsoft SMTP Server (TLS) id 15.0.1497.48; Tue, 6 Jun 2023 17:17:15 -0700 Received: from maili.marvell.com (10.69.176.80) by DC5-EXCH02.marvell.com (10.69.176.39) with Microsoft SMTP Server id 15.0.1497.48 via Frontend Transport; Tue, 6 Jun 2023 17:17:15 -0700 Received: from vpnclient.wrightpinski.org.com (unknown [10.69.242.187]) by maili.marvell.com (Postfix) with ESMTP id 6B9B43F7092; Tue, 6 Jun 2023 17:17:15 -0700 (PDT) To: CC: Andrew Pinski Subject: [PATCH 2/2] Add match patterns for `a ? onezero : onezero` where one of the two operands are constant Date: Tue, 6 Jun 2023 17:17:06 -0700 Message-ID: <20230607001706.3000011-2-apinski@marvell.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20230607001706.3000011-1-apinski@marvell.com> References: <20230607001706.3000011-1-apinski@marvell.com> MIME-Version: 1.0 X-Proofpoint-ORIG-GUID: qbfuuVS9ZCnbCfnnDuW0Ox6oqceerEEp X-Proofpoint-GUID: qbfuuVS9ZCnbCfnnDuW0Ox6oqceerEEp X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.254,Aquarius:18.0.957,Hydra:6.0.573,FMLib:17.11.176.26 definitions=2023-06-06_18,2023-06-06_02,2023-05-22_02 X-Spam-Status: No, score=-14.6 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, RCVD_IN_DNSWL_LOW, SPF_HELO_NONE, SPF_PASS, TXREP, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) 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: , X-Patchwork-Original-From: Andrew Pinski via Gcc-patches From: Andrew Pinski Reply-To: Andrew Pinski Errors-To: gcc-patches-bounces+patchwork=sourceware.org@gcc.gnu.org Sender: "Gcc-patches" This adds a match pattern that are for boolean values that optimizes `a ? onezero : 0` to `a & onezero` and `a ? 1 : onezero` to `a | onezero`. This was reported a few times and I thought I would finally add the match pattern for this. This hits a few times in GCC itself too. Notes on the testcases: * phi-opt-2.c: This now is optimized to `a & b` in phiopt rather than ifcombine * phi-opt-25b.c: The test part that was failing was parity which now gets `x & y` treatment. * ssa-thread-21.c: there is no longer a threading opportunity, so need to disable phiopt. Note PR 109957 is filed for the now missing optimization in that testcase too. gcc/ChangeLog: PR tree-optimization/89263 PR tree-optimization/99069 PR tree-optimization/20083 PR tree-optimization/94898 * match.pd: Add patterns to optimize `a ? onezero : onezero` with one of the operands are constant. gcc/testsuite/ChangeLog: * gcc.dg/tree-ssa/phi-opt-2.c: Adjust the testcase. * gcc.dg/tree-ssa/phi-opt-25b.c: Adjust the testcase. * gcc.dg/tree-ssa/ssa-thread-21.c: Disable phiopt. * gcc.dg/tree-ssa/phi-opt-27.c: New test. * gcc.dg/tree-ssa/phi-opt-28.c: New test. * gcc.dg/tree-ssa/phi-opt-29.c: New test. * gcc.dg/tree-ssa/phi-opt-30.c: New test. * gcc.dg/tree-ssa/phi-opt-31.c: New test. * gcc.dg/tree-ssa/phi-opt-32.c: New test. --- gcc/match.pd | 18 ++++++ gcc/testsuite/gcc.dg/tree-ssa/phi-opt-2.c | 12 ++-- gcc/testsuite/gcc.dg/tree-ssa/phi-opt-25b.c | 8 ++- gcc/testsuite/gcc.dg/tree-ssa/phi-opt-27.c | 14 +++++ gcc/testsuite/gcc.dg/tree-ssa/phi-opt-28.c | 14 +++++ gcc/testsuite/gcc.dg/tree-ssa/phi-opt-29.c | 25 +++++++++ gcc/testsuite/gcc.dg/tree-ssa/phi-opt-30.c | 55 +++++++++++++++++++ gcc/testsuite/gcc.dg/tree-ssa/phi-opt-31.c | 15 +++++ gcc/testsuite/gcc.dg/tree-ssa/phi-opt-32.c | 12 ++++ gcc/testsuite/gcc.dg/tree-ssa/ssa-thread-21.c | 3 +- 10 files changed, 165 insertions(+), 11 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/phi-opt-27.c create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/phi-opt-28.c create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/phi-opt-29.c create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/phi-opt-30.c create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/phi-opt-31.c create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/phi-opt-32.c diff --git a/gcc/match.pd b/gcc/match.pd index f97ff7ef760..dc36927cd0f 100644 --- a/gcc/match.pd +++ b/gcc/match.pd @@ -4721,6 +4721,24 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) ) ) +(simplify + (cond @0 zero_one_valued_p@1 zero_one_valued_p@2) + (switch + /* bool0 ? bool1 : 0 -> bool0 & bool1 */ + (if (integer_zerop (@2)) + (bit_and (convert @0) @1)) + /* bool0 ? 0 : bool2 -> (bool0^1) & bool2 */ + (if (integer_zerop (@1)) + (bit_and (bit_xor (convert @0) { build_one_cst (type); } ) @2)) + /* bool0 ? 1 : bool2 -> bool0 | bool2 */ + (if (integer_onep (@1)) + (bit_ior (convert @0) @2)) + /* bool0 ? bool1 : 1 -> (bool0^1) | bool1 */ + (if (integer_onep (@2)) + (bit_ior (bit_xor (convert @0) @2) @1)) + ) +) + /* Optimize # x_5 in range [cst1, cst2] where cst2 = cst1 + 1 x_5 ? cstN ? cst4 : cst3 diff --git a/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-2.c b/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-2.c index 5c7815e2c1a..006e8e83052 100644 --- a/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-2.c +++ b/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-2.c @@ -14,10 +14,8 @@ _Bool f1(_Bool a, _Bool b) } -/* There should be only one if, the outer one; the inner one - should have been changed to straight line code with the - value of b (except that we don't fold ! (b != 0) into b - which can be fixed in a different patch). - Test this only when known to be !LOGICAL_OP_NON_SHORT_CIRCUIT, - otherwise ifcombine may convert this into return a & b;. */ -/* { dg-final { scan-tree-dump-times "if" 1 "optimized" } } */ +/* There should be no if statements and be fold into just return a & b. + This can be done without ifcombine but in phiopt where a ? b : 0 is + converted into a & b. */ +/* { dg-final { scan-tree-dump-not "if" "optimized" } } */ +/* { dg-final { scan-tree-dump-times " & " 1 "optimized" } } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-25b.c b/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-25b.c index 698a20f7a56..7298da0c96e 100644 --- a/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-25b.c +++ b/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-25b.c @@ -65,6 +65,8 @@ int test_popcountll(unsigned long long x, unsigned long long y) return x ? __builtin_popcountll(y) : 0; } -/* 4 types of functions, each with 3 types and there are 2 goto each */ -/* { dg-final { scan-tree-dump-times "goto " 24 "optimized" } } */ - +/* 3 types of functions (not including parity), each with 3 types and there are 2 goto each */ +/* { dg-final { scan-tree-dump-times "goto " 18 "optimized" } } */ +/* { dg-final { scan-tree-dump-times "x_..D. != 0" 12 "optimized" } } */ +/* parity case will be optimized to x!=0 & parity(y) . */ +/* { dg-final { scan-tree-dump-times " & " 3 "optimized" } } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-27.c b/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-27.c new file mode 100644 index 00000000000..11f85b91644 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-27.c @@ -0,0 +1,14 @@ +/* { dg-do compile } */ +/* { dg-options "-O1 -fdump-tree-optimized" } */ + +_Bool f1(_Bool a, _Bool b) +{ + if (a) + return b; + return 0; +} + + +/* There should be no if statements and be fold into just return a & b. */ +/* { dg-final { scan-tree-dump-not "if" "optimized" } } */ +/* { dg-final { scan-tree-dump-times " & " 1 "optimized" } } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-28.c b/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-28.c new file mode 100644 index 00000000000..43dadd9341f --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-28.c @@ -0,0 +1,14 @@ +/* { dg-do compile } */ +/* { dg-options "-O1 -fdump-tree-optimized" } */ + +_Bool f1(_Bool a, _Bool b) +{ + if (a) + return 1; + return b; +} + + +/* There should be no if statements and be fold into just return a & b. */ +/* { dg-final { scan-tree-dump-not "if" "optimized" } } */ +/* { dg-final { scan-tree-dump-times " \\\| " 1 "optimized" } } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-29.c b/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-29.c new file mode 100644 index 00000000000..53aa01df102 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-29.c @@ -0,0 +1,25 @@ +/* PR tree-optimization/89263 */ +/* { dg-do compile } */ +/* { dg-options "-O2 -fdump-tree-optimized-raw" } */ + +_Bool f0(_Bool a, _Bool b) +{ + return a ? b : 0; +} +_Bool f1(_Bool a, _Bool b) +{ + return a ? b : 1; +} +_Bool t0(_Bool a, _Bool b) +{ + return a ? 0 : b; +} +_Bool t1(_Bool a, _Bool b) +{ + return a ? 1 : b; +} + +/* { dg-final { scan-tree-dump-not "gimple_cond " "optimized" } } */ +/* { dg-final { scan-tree-dump-times "bit_and_expr," 2 "optimized" } } */ +/* { dg-final { scan-tree-dump-times "bit_ior_expr," 2 "optimized" } } */ +/* { dg-final { scan-tree-dump-times "bit_not_expr," 2 "optimized" } } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-30.c b/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-30.c new file mode 100644 index 00000000000..cdfee269b3d --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-30.c @@ -0,0 +1,55 @@ +/* PR tree-optimization/20083 */ +/* { dg-do compile } */ +/* { dg-options "-O2 -fdump-tree-optimized-raw" } */ + + +int f(int i, int j, int l) +{ + int k = 0; + if (i) + k = 1; + if (j) + k = 1; + if (l) + k = 1; + return k; +} +int f1(int i, int j, int l) +{ + int k = 0; + if (i) + k = 1; + else if (j) + k = 1; + else if (l) + k = 1; + return k; +} +int f2(int i, int j, int l) +{ + return i||j||l; +} +int f3(int i, int j, int l) +{ + int t = i | j; + _Bool t1 = l != 0; + _Bool t2 = t ? 1 : t1; + return t2; +} + +int f4(int i, int j, int l) +{ + int t = i | j; + _Bool t1 = l != 0; + _Bool t2; + if (t) + t2 = 1; + else + t2 = t1; + return t2; +} + +/* { dg-final { scan-tree-dump-not "gimple_cond " "optimized" } } */ +/* 2 ior for each function. */ +/* { dg-final { scan-tree-dump-times "bit_ior_expr," 10 "optimized" } } */ +/* { dg-final { scan-tree-dump-times "ne_expr," 5 "optimized" } } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-31.c b/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-31.c new file mode 100644 index 00000000000..e312cdbdf52 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-31.c @@ -0,0 +1,15 @@ +/* PR tree-optimization/94898 */ +/* { dg-do compile } */ +/* { dg-options "-O2 -fdump-tree-optimized-raw" } */ + + +_Bool f(int x, int y) +{ + if (x >= y) + return x - y; + return 0; +} + +/* { dg-final { scan-tree-dump-not "gimple_cond " "optimized" } } */ +/* { dg-final { scan-tree-dump-times "gt_expr," 1 "optimized" } } */ +/* { dg-final { scan-tree-dump-not "ne_expr," "optimized" } } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-32.c b/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-32.c new file mode 100644 index 00000000000..f51e79fd066 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-32.c @@ -0,0 +1,12 @@ +/* PR tree-optimization/99069 */ +/* { dg-do compile } */ +/* { dg-options "-O2 -fdump-tree-optimized-raw" } */ + +_Bool f(_Bool x, _Bool y) +{ + return (x ? y : 0) ? x : 0; +} + + +/* { dg-final { scan-tree-dump-not "gimple_cond " "optimized" } } */ +/* { dg-final { scan-tree-dump-times "bit_and_expr," 1 "optimized" } } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-thread-21.c b/gcc/testsuite/gcc.dg/tree-ssa/ssa-thread-21.c index 16537ccfb61..1123b3ebbdf 100644 --- a/gcc/testsuite/gcc.dg/tree-ssa/ssa-thread-21.c +++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-thread-21.c @@ -1,5 +1,5 @@ /* { dg-do compile } */ -/* { dg-options "-O2 -fdump-tree-thread2-stats -fdump-tree-optimized" } */ +/* { dg-options "-O2 -fdump-tree-thread2-stats -fdump-tree-optimized -fno-ssa-phiopt" } */ long a; int b; @@ -19,6 +19,7 @@ int main() { a = b; } +/* Disable phiopt as the threading opportunity goes away. */ /* We need to perform a non-multi-way branch FSM thread creating an irreducible loop in thread2 to allow followup threading to remove the call to foo (). */