[Bug tree-optimization/64728] [5 Regression] internal compiler error: SSA corruption

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64728

--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> ---
Index: tree-ssa-coalesce.c
===================================================================
--- tree-ssa-coalesce.c (revision 219989)
+++ tree-ssa-coalesce.c (working copy)
@@ -1213,8 +1215,11 @@ coalesce_partitions (var_map map, ssa_co
                 gsi_next (&gsi))
              {
                gphi *phi = gsi.phi ();
-               tree res = PHI_RESULT (phi);
                tree arg = PHI_ARG_DEF (phi, e->dest_idx);
+               if (SSA_NAME_IS_DEFAULT_DEF (arg))
+                 continue;
+
+               tree res = PHI_RESULT (phi);
                int v1 = SSA_NAME_VERSION (res);
                int v2 = SSA_NAME_VERSION (arg);


fixes it for me.