tree-optimization/109331 - make sure to clean up the CFG after forwprop
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Commit Message
When forwprop discovers unreachable code or makes decisions based
on unreachable edges make sure to cleanup the CFG since otherwise
SSA form can become invalid.
Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.
PR tree-optimization/109331
* tree-ssa-forwprop.cc (pass_forwprop::execute): When we
discover a taken edge make sure to cleanup the CFG.
* gcc.dg/torture/pr109331.c: New testcase.
---
gcc/testsuite/gcc.dg/torture/pr109331.c | 16 ++++++++++++++++
gcc/tree-ssa-forwprop.cc | 6 +++++-
2 files changed, 21 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/gcc.dg/torture/pr109331.c
new file mode 100644
@@ -0,0 +1,16 @@
+/* { dg-do compile } */
+
+char *ustol_dpp;
+void ustol(int flags)
+{
+ char *s;
+ if (s)
+ flags |= 3;
+ switch (flags & 3)
+ case 3:
+ while (*s)
+ case '+':
+ ++s;
+ if (flags)
+ ustol_dpp = s;
+}
@@ -4046,7 +4046,11 @@ pass_forwprop::execute (function *fun)
/* Mark outgoing exectuable edges. */
if (edge e = find_taken_edge (bb, NULL))
- e->flags |= EDGE_EXECUTABLE;
+ {
+ e->flags |= EDGE_EXECUTABLE;
+ if (EDGE_COUNT (bb->succs) > 1)
+ cfg_changed = true;
+ }
else
{
FOR_EACH_EDGE (e, ei, bb->succs)