From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by sourceware.org (Postfix) with ESMTPS id 82DEA3858D32 for ; Mon, 30 Jan 2023 09:50:39 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 82DEA3858D32 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=suse.de Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=suse.de Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 4961E1FE0D for ; Mon, 30 Jan 2023 09:50:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1675072238; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc: mime-version:mime-version:content-type:content-type; bh=81+PRYijJl4QJBlFhLR00Nj2yk5dVDgkk3Ehx5LsHBM=; b=n2yt9k862HfZPXbusQ3znyHdK36lPEx4t5OVHIMLzFYAt2lC/YsMSMETDezUlR++3FkLZL A5MsrytLQTvGjCkTz8vNpAG2a4EDeCf+dRS+BVjcxdfd8u1uBWxwtCGMGbeXNdhMpjnbN0 p3t7JXFeDci9vUVPAU19bGrps1oDrJ8= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1675072238; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc: mime-version:mime-version:content-type:content-type; bh=81+PRYijJl4QJBlFhLR00Nj2yk5dVDgkk3Ehx5LsHBM=; b=W11Fapk6/KMkM/Nj2dQ53Ep03cMuzOZeZDPAVlrlF5H7RwEZOu2RfbcBJB4BD4mMtN+Z++ SEzynloP//LJ4kAg== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 3665C13444 for ; Mon, 30 Jan 2023 09:50:38 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id UAorDO6S12NFdgAAMHmgww (envelope-from ) for ; Mon, 30 Jan 2023 09:50:38 +0000 Date: Mon, 30 Jan 2023 10:50:37 +0100 (CET) From: Richard Biener To: gcc-patches@gcc.gnu.org Subject: [PATCH] tree-optimization/108574 - wrong-code with PRE PHI node processing MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Message-Id: <20230130095038.3665C13444@imap2.suse-dmz.suse.de> X-Spam-Status: No, score=-11.8 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,GIT_PATCH_0,SPF_HELO_NONE,SPF_PASS,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: The PR108523 was too optimistic in replacing the same value with an equivalence from a possibly not taken edge. The following rectifies this and instead refrains from using the equivalence in the problematic cases. Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed. PR tree-optimization/108574 * tree-ssa-sccvn.cc (visit_phi): Instead of swapping sameval and def, ignore the equivalence if there's the danger of oscillating between two values. * gcc.dg/torture/pr108574-1.c: New testcase. * gcc.dg/torture/pr108574-2.c: Likewise. * gcc.dg/torture/pr108574-3.c: Likewise. --- gcc/testsuite/gcc.dg/torture/pr108574-1.c | 19 ++++++++++++++++ gcc/testsuite/gcc.dg/torture/pr108574-2.c | 25 +++++++++++++++++++++ gcc/testsuite/gcc.dg/torture/pr108574-3.c | 27 +++++++++++++++++++++++ gcc/tree-ssa-sccvn.cc | 11 +++++---- 4 files changed, 76 insertions(+), 6 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/torture/pr108574-1.c create mode 100644 gcc/testsuite/gcc.dg/torture/pr108574-2.c create mode 100644 gcc/testsuite/gcc.dg/torture/pr108574-3.c diff --git a/gcc/testsuite/gcc.dg/torture/pr108574-1.c b/gcc/testsuite/gcc.dg/torture/pr108574-1.c new file mode 100644 index 00000000000..7066b5ee2a2 --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr108574-1.c @@ -0,0 +1,19 @@ +/* { dg-do run } */ + +int a = 1, b, c = 2, d; +int main() { + if (b) + goto L2; + L1: + { + int e = c; + a = 1 % a; + while (e && 1 <= d) + ; + d >= b; + L2: + if (1 >= e) + goto L1; + } + return 0; +} diff --git a/gcc/testsuite/gcc.dg/torture/pr108574-2.c b/gcc/testsuite/gcc.dg/torture/pr108574-2.c new file mode 100644 index 00000000000..1e38d087646 --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr108574-2.c @@ -0,0 +1,25 @@ +/* { dg-do run } */ + +int a, b, c, d, e, f, g = -1, h; +void l() { + if (!e) + goto i; + for (; g; g++) { + b = ~d; + int j = 0, k = 1; + if (k && (b || f)) + j = b; + i: + a = ~j; + } +} +int main() { + h = 3; + for (; h; h--) { + e = 1; + int m = ~a, n = 1 % m; + c = n; + l(); + } + return 0; +} diff --git a/gcc/testsuite/gcc.dg/torture/pr108574-3.c b/gcc/testsuite/gcc.dg/torture/pr108574-3.c new file mode 100644 index 00000000000..3c9146e31ac --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr108574-3.c @@ -0,0 +1,27 @@ +/* { dg-do run } */ + +int a = 3557301289, d; +char b, f; +unsigned short c = 241; +short e, g; +static void h() { + if (!a) + goto i; + b = a; + for (; a < 2; a = b) { + unsigned short j; + if (c || !g) { + j = c; + i: + e = j; + } + f = j; + d = ~(f & ~2880764155); + while (d > -2316069) + ; + } +} +int main() { + h(); + return 0; +} diff --git a/gcc/tree-ssa-sccvn.cc b/gcc/tree-ssa-sccvn.cc index edb553b07cb..028bedbc9a0 100644 --- a/gcc/tree-ssa-sccvn.cc +++ b/gcc/tree-ssa-sccvn.cc @@ -5908,7 +5908,8 @@ visit_phi (gimple *phi, bool *inserted, bool backedges_varying_p) if (! val && vnresult && vnresult->predicated_values) { val = vn_nary_op_get_predicated_value (vnresult, e->src); - if (val && integer_truep (val)) + if (val && integer_truep (val) + && !(sameval_e && (sameval_e->flags & EDGE_DFS_BACK))) { if (dump_file && (dump_flags & TDF_DETAILS)) { @@ -5919,8 +5920,6 @@ visit_phi (gimple *phi, bool *inserted, bool backedges_varying_p) fprintf (dump_file, " are equal on edge %d -> %d\n", e->src->index, e->dest->index); } - if (sameval_e && (sameval_e->flags & EDGE_DFS_BACK)) - sameval = def; continue; } /* If on all previous edges the value was equal to def @@ -5928,7 +5927,8 @@ visit_phi (gimple *phi, bool *inserted, bool backedges_varying_p) if (EDGE_COUNT (bb->preds) == 2 && (val = vn_nary_op_get_predicated_value (vnresult, EDGE_PRED (bb, 0)->src)) - && integer_truep (val)) + && integer_truep (val) + && !(e->flags & EDGE_DFS_BACK)) { if (dump_file && (dump_flags & TDF_DETAILS)) { @@ -5940,8 +5940,7 @@ visit_phi (gimple *phi, bool *inserted, bool backedges_varying_p) EDGE_PRED (bb, 0)->src->index, EDGE_PRED (bb, 0)->dest->index); } - if (!(e->flags & EDGE_DFS_BACK)) - sameval = def; + sameval = def; continue; } } -- 2.35.3