8332644: Improve graph optimizations

Reviewed-by: mbalao, andrew
Backport-of: 7c16d649a8118d2e7ee77cedba87e620c83294b4

Author: franferrax

hotspot/src/share/vm/opto/loopnode.cpp

@@ -1220,7 +1220,7 @@ Node *LoopLimitNode::Ideal(PhaseGVN *phase, bool can_reshape) {
 
   const TypeInt* init_t  = phase->type(in(Init) )->is_int();
   const TypeInt* limit_t = phase->type(in(Limit))->is_int();
-  int stride_p;
+  jlong stride_p;
   jlong lim, ini;
   julong max;
   if (stride_con > 0) {
@@ -1229,10 +1229,10 @@ Node *LoopLimitNode::Ideal(PhaseGVN *phase, bool can_reshape) {
     ini = init_t->_lo;
     max = (julong)max_jint;
   } else {
-    stride_p = -stride_con;
+    stride_p = -(jlong)stride_con;
     lim = init_t->_hi;
     ini = limit_t->_lo;
-    max = (julong)min_jint;
+    max = (julong)(juint)min_jint; // double cast to get 0x0000000080000000, not 0xffffffff80000000
   }
   julong range = lim - ini + stride_p;
   if (range <= max) {