8307619: C2 failed: Not monotonic (AndI CastII LShiftI) in TestShiftCastAndNotification.java

Reviewed-by: chagedorn, thartmann

Author: eme64

src/hotspot/share/opto/mulnode.cpp

@@ -1923,13 +1923,15 @@ bool MulNode::AndIL_shift_and_mask_is_always_zero(PhaseGVN* phase, Node* shift,
   if (mask == nullptr || shift == nullptr) {
     return false;
   }
+  const TypeInteger* mask_t = phase->type(mask)->isa_integer(bt);
+  if (mask_t == nullptr || phase->type(shift)->isa_integer(bt) == nullptr) {
+    return false;
+  }
   shift = shift->uncast();
   if (shift == nullptr) {
     return false;
   }
-  const TypeInteger* mask_t = phase->type(mask)->isa_integer(bt);
-  const TypeInteger* shift_t = phase->type(shift)->isa_integer(bt);
-  if (mask_t == nullptr || shift_t == nullptr) {
+  if (phase->type(shift)->isa_integer(bt) == nullptr) {
     return false;
   }
   BasicType shift_bt = bt;
@@ -1946,6 +1948,9 @@ bool MulNode::AndIL_shift_and_mask_is_always_zero(PhaseGVN* phase, Node* shift,
     if (val->Opcode() == Op_LShiftI) {
       shift_bt = T_INT;
       shift = val;
+      if (phase->type(shift)->isa_integer(bt) == nullptr) {
+        return false;
+      }
     }
   }
   if (shift->Opcode() != Op_LShift(shift_bt)) {