commit 82b0345f6137b112728590d7c010dcd2cef08514
Author: Andrew MacLeod <amacleod@redhat.com>
Date:   Tue Nov 1 13:18:33 2022 -0400

    Make sure ssa-name is valid.
    
            PR tree-optimization/107497
            * tree-vrp.cc (remove_unreachable::remove_and_update_globals):
            Check that ssa-name still exists before accessing it.

diff --git a/gcc/tree-vrp.cc b/gcc/tree-vrp.cc
index f0e4d37bef0..39f7eb7a75e 100644
--- a/gcc/tree-vrp.cc
+++ b/gcc/tree-vrp.cc
@@ -180,7 +180,7 @@ remove_unreachable::remove_and_update_globals (bool final_p)
   bitmap_copy (dce, all_exports);
   // Don't attempt to DCE parameters.
   EXECUTE_IF_SET_IN_BITMAP (all_exports, 0, i, bi)
-    if (SSA_NAME_IS_DEFAULT_DEF (ssa_name (i)))
+    if (!ssa_name (i) || SSA_NAME_IS_DEFAULT_DEF (ssa_name (i)))
       bitmap_clear_bit (dce, i);
   simple_dce_from_worklist (dce);