[Bug tree-optimization/84057] [8 Regression] ICE: Segmentation fault (in can_remove_branch_p)

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84057

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
Sth like the following works for example.

Index: gcc/tree-ssa-loop-ivcanon.c
===================================================================
--- gcc/tree-ssa-loop-ivcanon.c (revision 257077)
+++ gcc/tree-ssa-loop-ivcanon.c (working copy)
@@ -660,14 +660,21 @@ unloop_loops (bitmap loop_closed_ssa_inv
   loops_to_unloop.release ();
   loops_to_unloop_nunroll.release ();

-  /* Remove edges in peeled copies.  */
+  /* Remove edges in peeled copies.  Given remove_path removes dominated
+     regions we need to cope with removal of already removed paths.  */
   unsigned i;
   edge e;
+  auto_vec<int, 20> src_bbs;
+  src_bbs.reserve_exact (20);
   FOR_EACH_VEC_ELT (edges_to_remove, i, e)
-    {
-      bool ok = remove_path (e, irred_invalidated,
loop_closed_ssa_invalidated);
-      gcc_assert (ok);
-    }
+    src_bbs.quick_push (e->src->index);
+  FOR_EACH_VEC_ELT (edges_to_remove, i, e)
+    if (BASIC_BLOCK_FOR_FN (cfun, src_bbs[i]))
+      {
+       bool ok = remove_path (e, irred_invalidated,
+                              loop_closed_ssa_invalidated);
+       gcc_assert (ok);
+      }
   edges_to_remove.release ();
 }