tree-optimization/109327 - forwprop stmt removal issue
Commit Message
There's interfering between the to_removed queue and other mechanisms
removing stmts, in this case remove_prop_source_from_use. The following
makes the to_remove queue draining more permissive.
Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.
PR tree-optimization/109327
* tree-ssa-forwprop.cc (pass_forwprop::execute): Deal with
already removed stmts when draining to_remove.
* gcc.dg/pr109327.c: New testcase.
---
gcc/testsuite/gcc.dg/pr109327.c | 15 +++++++++++++++
gcc/tree-ssa-forwprop.cc | 4 ++++
2 files changed, 19 insertions(+)
create mode 100644 gcc/testsuite/gcc.dg/pr109327.c
new file mode 100644
@@ -0,0 +1,15 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fno-tree-ccp" } */
+
+int a;
+void b(int c) {}
+int main()
+{
+ int d = 0, *e = &a;
+ if (d) {
+ int *f = e;
+ while (a)
+ b(e != f);
+ }
+ return 0;
+}
@@ -4061,6 +4061,10 @@ pass_forwprop::execute (function *fun)
while (!to_remove.is_empty())
{
gimple *stmt = to_remove.pop ();
+ /* For example remove_prop_source_from_use can remove stmts queued
+ for removal. Deal with this gracefully. */
+ if (!gimple_bb (stmt))
+ continue;
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, "Removing dead stmt ");