From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 2153) id 4944138346BB; Tue, 10 May 2022 08:23:10 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 4944138346BB MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="utf-8" From: Jakub Jelinek To: gcc-cvs@gcc.gnu.org Subject: [gcc r10-10671] store-merging: Fix up a -fcompare-debug bug in get_status_for_store_merging [PR104263] X-Act-Checkin: gcc X-Git-Author: Jakub Jelinek X-Git-Refname: refs/heads/releases/gcc-10 X-Git-Oldrev: 42d66df40b5a12e1b7e77f0901ee8a6710cabd5f X-Git-Newrev: 7bb29feb789dfa05297998e1c241d438307cc3d2 Message-Id: <20220510082310.4944138346BB@sourceware.org> Date: Tue, 10 May 2022 08:23:10 +0000 (GMT) X-BeenThere: gcc-cvs@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-cvs mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 10 May 2022 08:23:10 -0000 https://gcc.gnu.org/g:7bb29feb789dfa05297998e1c241d438307cc3d2 commit r10-10671-g7bb29feb789dfa05297998e1c241d438307cc3d2 Author: Jakub Jelinek Date: Fri Jan 28 19:02:26 2022 +0100 store-merging: Fix up a -fcompare-debug bug in get_status_for_store_merging [PR104263] As mentioned in the PRthe following testcase fails, because the last stmt of a bb with -g is a debug stmt and get_status_for_store_merging uses gimple_seq_last_stmt (bb_seq (bb)) when testing if it is valid for store merging. The debug stmt isn't valid, while a stmt at that position with -g0 is valid and so the divergence. As we walk the whole bb already, this patch just remembers the last non-debug stmt, so that we don't need to skip backwards debug stmts at the end of the bb to find last real stmt. 2022-01-28 Jakub Jelinek PR tree-optimization/104263 * gimple-ssa-store-merging.c (get_status_for_store_merging): For cfun->can_throw_non_call_exceptions && cfun->eh test whether last non-debug stmt in the bb is store_valid_for_store_merging_p rather than last stmt. * gcc.dg/pr104263.c: New test. (cherry picked from commit a591c71b41e18e4ff86852a974592af4962aef57) Diff: --- gcc/gimple-ssa-store-merging.c | 5 ++++- gcc/testsuite/gcc.dg/pr104263.c | 25 +++++++++++++++++++++++++ 2 files changed, 29 insertions(+), 1 deletion(-) diff --git a/gcc/gimple-ssa-store-merging.c b/gcc/gimple-ssa-store-merging.c index 0623e6ec80b..4093ccaaafc 100644 --- a/gcc/gimple-ssa-store-merging.c +++ b/gcc/gimple-ssa-store-merging.c @@ -4963,6 +4963,7 @@ get_status_for_store_merging (basic_block bb) unsigned int num_statements = 0; gimple_stmt_iterator gsi; edge e; + gimple *last_stmt = NULL; for (gsi = gsi_after_labels (bb); !gsi_end_p (gsi); gsi_next (&gsi)) { @@ -4971,6 +4972,8 @@ get_status_for_store_merging (basic_block bb) if (is_gimple_debug (stmt)) continue; + last_stmt = stmt; + if (store_valid_for_store_merging_p (stmt) && ++num_statements >= 2) break; } @@ -4979,7 +4982,7 @@ get_status_for_store_merging (basic_block bb) return BB_INVALID; if (cfun->can_throw_non_call_exceptions && cfun->eh - && store_valid_for_store_merging_p (gimple_seq_last_stmt (bb_seq (bb))) + && store_valid_for_store_merging_p (last_stmt) && (e = find_fallthru_edge (bb->succs)) && e->dest == bb->next_bb) return BB_EXTENDED_VALID; diff --git a/gcc/testsuite/gcc.dg/pr104263.c b/gcc/testsuite/gcc.dg/pr104263.c new file mode 100644 index 00000000000..79b548c629c --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr104263.c @@ -0,0 +1,25 @@ +/* PR tree-optimization/104263 */ +/* { dg-do compile } */ +/* { dg-options "-O2 -fcompare-debug -fnon-call-exceptions -fno-inline-small-functions" } */ + +int n; + +int +bar (void) +{ + int a; + + n = 0; + a = 0; + + return n; +} + +__attribute__ ((pure, returns_twice)) int +foo (void) +{ + n = bar () + 1; + foo (); + + return 0; +}