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| author | Jakub Jelinek <jakub@redhat.com> | 2022-01-28 19:02:26 +0100 |
|---|---|---|
| committer | Jakub Jelinek <jakub@redhat.com> | 2022-01-28 19:02:26 +0100 |
| commit | a591c71b41e18e4ff86852a974592af4962aef57 (patch) | |
| tree | beb18d6e1804d566e8412e19556fa0dfd6e98a03 /gcc | |
| parent | 90c31ff339015ddd89ac519656fbd23a36ee6271 (diff) | |
| download | gcc-a591c71b41e18e4ff86852a974592af4962aef57.zip gcc-a591c71b41e18e4ff86852a974592af4962aef57.tar.gz gcc-a591c71b41e18e4ff86852a974592af4962aef57.tar.bz2 | |
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 <jakub@redhat.com>
PR tree-optimization/104263
* gimple-ssa-store-merging.cc (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.
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/gimple-ssa-store-merging.cc | 5 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/pr104263.c | 25 |
2 files changed, 29 insertions, 1 deletions
diff --git a/gcc/gimple-ssa-store-merging.cc b/gcc/gimple-ssa-store-merging.cc index eb70d90..e2e2157 100644 --- a/gcc/gimple-ssa-store-merging.cc +++ b/gcc/gimple-ssa-store-merging.cc @@ -5364,6 +5364,7 @@ get_status_for_store_merging (basic_block bb) unsigned int num_constructors = 0; gimple_stmt_iterator gsi; edge e; + gimple *last_stmt = NULL; for (gsi = gsi_after_labels (bb); !gsi_end_p (gsi); gsi_next (&gsi)) { @@ -5372,6 +5373,8 @@ 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; @@ -5398,7 +5401,7 @@ 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 0000000..79b548c --- /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; +} |