diff -r dfe27f03244a -r e9ff18c4ace7 src/share/vm/opto/compile.cpp
--- a/src/share/vm/opto/compile.cpp	Tue Jun 01 11:48:33 2010 -0700
+++ b/src/share/vm/opto/compile.cpp	Wed Jun 02 22:45:42 2010 -0700
@@ -2176,14 +2176,14 @@
 
 #ifdef _LP64
   case Op_CastPP:
-    if (n->in(1)->is_DecodeN() && Universe::narrow_oop_use_implicit_null_checks()) {
+    if (n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
       Compile* C = Compile::current();
       Node* in1 = n->in(1);
       const Type* t = n->bottom_type();
       Node* new_in1 = in1->clone();
       new_in1->as_DecodeN()->set_type(t);
 
-      if (!Matcher::clone_shift_expressions) {
+      if (!Matcher::narrow_oop_use_complex_address()) {
         //
         // x86, ARM and friends can handle 2 adds in addressing mode
         // and Matcher can fold a DecodeN node into address by using
@@ -2231,8 +2231,12 @@
         new_in2 = in2->in(1);
       } else if (in2->Opcode() == Op_ConP) {
         const Type* t = in2->bottom_type();
-        if (t == TypePtr::NULL_PTR && Universe::narrow_oop_use_implicit_null_checks()) {
-          new_in2 = ConNode::make(C, TypeNarrowOop::NULL_PTR);
+        if (t == TypePtr::NULL_PTR) {
+          // Don't convert CmpP null check into CmpN if compressed
+          // oops implicit null check is not generated.
+          // This will allow to generate normal oop implicit null check.
+          if (Matcher::gen_narrow_oop_implicit_null_checks())
+            new_in2 = ConNode::make(C, TypeNarrowOop::NULL_PTR);
           //
           // This transformation together with CastPP transformation above
           // will generated code for implicit NULL checks for compressed oops.
@@ -2289,9 +2293,9 @@
 
   case Op_DecodeN:
     assert(!n->in(1)->is_EncodeP(), "should be optimized out");
-    // DecodeN could be pinned on Sparc where it can't be fold into
+    // DecodeN could be pinned when it can't be fold into
     // an address expression, see the code for Op_CastPP above.
-    assert(n->in(0) == NULL || !Matcher::clone_shift_expressions, "no control except on sparc");
+    assert(n->in(0) == NULL || !Matcher::narrow_oop_use_complex_address(), "no control");
     break;
 
   case Op_EncodeP: {
@@ -2496,6 +2500,10 @@
     }
   }
 
+  // Skip next transformation if compressed oops are not used.
+  if (!UseCompressedOops || !Matcher::gen_narrow_oop_implicit_null_checks())
+    return;
+
   // Go over safepoints nodes to skip DecodeN nodes for debug edges.
   // It could be done for an uncommon traps or any safepoints/calls
   // if the DecodeN node is referenced only in a debug info.