https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118973
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |ASSIGNED
Assignee|unassigned at gcc dot gnu.org |rguenth at gcc dot
gnu.org
--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
The issue is we have a broken CFG with an empty BB with an outgoing abnormal
edge. Somebody failed to prune this edge. DCE it is:
> diff -u t.c.045t.dse1 t.c.046t.cddce1
--- t.c.045t.dse1 2025-02-24 09:30:15.013311568 +0100
+++ t.c.046t.cddce1 2025-02-24 09:30:15.017311568 +0100
@@ -31,10 +31,8 @@
;; basic block 5, loop depth 0
;; pred: 4
- operator new (4);
-;; succ: 7
+;; succ: 3
;; 6
-;; 3
;; basic block 6, loop depth 0
;; pred: 4
@@ -44,7 +42,6 @@
;; basic block 7, loop depth 0
;; pred: 2
-;; 5
<L3>:
resx 1
;; succ:
it doesn't look like DCE handles EH or abnormal edges in any special way ...
the intent was we preserve those, but removable call handling ignores this.
diff --git a/gcc/tree-ssa-dce.cc b/gcc/tree-ssa-dce.cc
index 461283ba858..3519694980e 100644
--- a/gcc/tree-ssa-dce.cc
+++ b/gcc/tree-ssa-dce.cc
@@ -392,8 +392,8 @@ mark_stmt_if_obviously_necessary (gimple *stmt, bool
aggressive)
gcall *call = as_a <gcall *> (stmt);
/* Never elide a noreturn call we pruned control-flow for. */
- if ((gimple_call_flags (call) & ECF_NORETURN)
- && gimple_call_ctrl_altering_p (call))
+ if (/*(gimple_call_flags (call) & ECF_NORETURN)
+ &&*/ gimple_call_ctrl_altering_p (call))
{
mark_stmt_necessary (call, true);
return;
fixes this.
