8254734: "dead loop detected" assert failure with patch from 8223051

Reviewed-by: chagedorn, kvn

Author: rwestrel

src/hotspot/share/opto/node.cpp

@@ -2420,6 +2420,29 @@ void Node::ensure_control_or_add_prec(Node* c) {
   }
 }
 
+bool Node::is_dead_loop_safe() const {
+  if (is_Phi()) {
+    return true;
+  }
+  if (is_Proj() && in(0) == NULL)  {
+    return true;
+  }
+  if ((_flags & (Flag_is_dead_loop_safe | Flag_is_Con)) != 0) {
+    if (!is_Proj()) {
+      return true;
+    }
+    if (in(0)->is_Allocate()) {
+      return false;
+    }
+    // MemNode::can_see_stored_value() peeks through the boxing call
+    if (in(0)->is_CallStaticJava() && in(0)->as_CallStaticJava()->is_boxing_method()) {
+      return false;
+    }
+    return true;
+  }
+  return false;
+}
+
 //=============================================================================
 //------------------------------yank-------------------------------------------
 // Find and remove

src/hotspot/share/opto/node.hpp

@@ -905,11 +905,7 @@ class Node {
 
   bool is_Con () const { return (_flags & Flag_is_Con) != 0; }
   // The data node which is safe to leave in dead loop during IGVN optimization.
-  bool is_dead_loop_safe() const {
-    return is_Phi() || (is_Proj() && in(0) == NULL) ||
-           ((_flags & (Flag_is_dead_loop_safe | Flag_is_Con)) != 0 &&
-            (!is_Proj() || !in(0)->is_Allocate()));
-  }
+  bool is_dead_loop_safe() const;
 
   // is_Copy() returns copied edge index (0 or 1)
   uint is_Copy() const { return (_flags & Flag_is_Copy); }