* [PATCH] tree-optimization/107803 - abnormal cleanup from the SSA propagator
@ 2022-11-22 11:05 Richard Biener
0 siblings, 0 replies; only message in thread
From: Richard Biener @ 2022-11-22 11:05 UTC (permalink / raw)
To: gcc-patches
The SSA propagator is missing abnormal cleanup which shows in a
sanity check in the uninit engine (and missed CFG verification).
The following adds that.
Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.
PR tree-optimization/107803
* tree-ssa-propagate.cc (substitute_and_fold_dom_walker): Add
need_ab_cleanup member.
(substitute_and_fold_dom_walker::before_dom_children): When
a stmt can no longer transfer control flow abnormally set
need_ab_cleanup.
(substitute_and_fold_engine::substitute_and_fold): Cleanup
abnormal control flow.
* g++.dg/pr107803.C: New testcase.
---
gcc/testsuite/g++.dg/pr107803.C | 19 +++++++++++++++++++
gcc/tree-ssa-propagate.cc | 20 ++++++++++++++++++--
2 files changed, 37 insertions(+), 2 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/pr107803.C
diff --git a/gcc/testsuite/g++.dg/pr107803.C b/gcc/testsuite/g++.dg/pr107803.C
new file mode 100644
index 00000000000..f814e968b69
--- /dev/null
+++ b/gcc/testsuite/g++.dg/pr107803.C
@@ -0,0 +1,19 @@
+// { dg-do compile }
+// { dg-options "-O -fno-tree-dominator-opts -fno-tree-fre -Wmaybe-uninitialized" }
+
+void printf(...);
+void __sigsetjmp_cancel() __attribute__((__returns_twice__));
+int z, main_ret;
+void func(void *) {}
+
+int
+main()
+{
+ int x;
+ void (*__cancel_routine)(void *)(func);
+ __sigsetjmp_cancel();
+ __cancel_routine(0);
+ if (main_ret)
+ x = z;
+ printf(x);
+}
diff --git a/gcc/tree-ssa-propagate.cc b/gcc/tree-ssa-propagate.cc
index 9dc4bfd85bf..d8b0aed4564 100644
--- a/gcc/tree-ssa-propagate.cc
+++ b/gcc/tree-ssa-propagate.cc
@@ -671,12 +671,14 @@ public:
stmts_to_remove.create (0);
stmts_to_fixup.create (0);
need_eh_cleanup = BITMAP_ALLOC (NULL);
+ need_ab_cleanup = BITMAP_ALLOC (NULL);
}
~substitute_and_fold_dom_walker ()
{
stmts_to_remove.release ();
stmts_to_fixup.release ();
BITMAP_FREE (need_eh_cleanup);
+ BITMAP_FREE (need_ab_cleanup);
}
edge before_dom_children (basic_block) final override;
@@ -689,6 +691,7 @@ public:
vec<gimple *> stmts_to_remove;
vec<gimple *> stmts_to_fixup;
bitmap need_eh_cleanup;
+ bitmap need_ab_cleanup;
class substitute_and_fold_engine *substitute_and_fold_engine;
@@ -838,8 +841,13 @@ substitute_and_fold_dom_walker::before_dom_children (basic_block bb)
folded. */
did_replace = false;
gimple *old_stmt = stmt;
- bool was_noreturn = (is_gimple_call (stmt)
- && gimple_call_noreturn_p (stmt));
+ bool was_noreturn = false;
+ bool can_make_abnormal_goto = false;
+ if (is_gimple_call (stmt))
+ {
+ was_noreturn = gimple_call_noreturn_p (stmt);
+ can_make_abnormal_goto = stmt_can_make_abnormal_goto (stmt);
+ }
/* Replace real uses in the statement. */
did_replace |= substitute_and_fold_engine->replace_uses_in (stmt);
@@ -905,6 +913,12 @@ substitute_and_fold_dom_walker::before_dom_children (basic_block bb)
if (maybe_clean_or_replace_eh_stmt (old_stmt, stmt))
bitmap_set_bit (need_eh_cleanup, bb->index);
+ /* If we turned a call with possible abnormal control transfer
+ into one that doesn't, remove abnormal edges. */
+ if (can_make_abnormal_goto
+ && !stmt_can_make_abnormal_goto (stmt))
+ bitmap_set_bit (need_ab_cleanup, bb->index);
+
/* If we turned a not noreturn call into a noreturn one
schedule it for fixup. */
if (!was_noreturn
@@ -1012,6 +1026,8 @@ substitute_and_fold_engine::substitute_and_fold (basic_block block)
if (!bitmap_empty_p (walker.need_eh_cleanup))
gimple_purge_all_dead_eh_edges (walker.need_eh_cleanup);
+ if (!bitmap_empty_p (walker.need_ab_cleanup))
+ gimple_purge_all_dead_abnormal_call_edges (walker.need_ab_cleanup);
/* Fixup stmts that became noreturn calls. This may require splitting
blocks and thus isn't possible during the dominator walk. Do this
--
2.35.3
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