8347426: Invalid value used for enum Cell in iTypeFlow::StateVector::meet_exception

Reviewed-by: dlong, kvn

Author: marc-chevalier

src/hotspot/share/ci/ciTypeFlow.cpp

@@ -500,8 +500,8 @@ bool ciTypeFlow::StateVector::meet_exception(ciInstanceKlass* exc,
   bool different = false;
 
   // Meet locals from incoming array.
-  Cell limit = local(_outer->max_locals()-1);
-  for (Cell c = start_cell(); c <= limit; c = next_cell(c)) {
+  Cell limit = local_limit_cell();
+  for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
     ciType* t1 = type_at(c);
     ciType* t2 = incoming->type_at(c);
     if (!t1->equals(t2)) {

src/hotspot/share/ci/ciTypeFlow.hpp

@@ -213,9 +213,12 @@ class ciTypeFlow : public ArenaObj {
       return (Cell)(outer()->max_locals() + stack_size());
     }
 
+    Cell local_limit_cell() const { return (Cell) outer()->max_locals(); }
+
     // Cell creation
     Cell      local(int lnum) const {
       assert(lnum < outer()->max_locals(), "index check");
+      assert(Cell_0 <= lnum && lnum <= Cell_max, "out of Cell's range");
       return (Cell)(lnum);
     }