diff src/share/vm/opto/cfgnode.cpp @ 899:55cb84cd1247

6865031: Application gives bad result (throws bad exception) with compressed oops Summary: Produce narrow type for new Phi from the original Phi type. Reviewed-by: cfang
author kvn
date Fri, 31 Jul 2009 12:04:07 -0700
parents 433f394ab509
children 15bbd3f505c0
line wrap: on
line diff
--- a/src/share/vm/opto/cfgnode.cpp	Thu Jul 30 16:05:56 2009 -0700
+++ b/src/share/vm/opto/cfgnode.cpp	Fri Jul 31 12:04:07 2009 -0700
@@ -1792,15 +1792,12 @@
   if (UseCompressedOops && can_reshape && progress == NULL) {
     bool may_push = true;
     bool has_decodeN = false;
-    Node* in_decodeN = NULL;
     for (uint i=1; i<req(); ++i) {// For all paths in
       Node *ii = in(i);
       if (ii->is_DecodeN() && ii->bottom_type() == bottom_type()) {
-        // Note: in_decodeN is used only to define the type of new phi.
-        // Find a non dead path otherwise phi type will be wrong.
+        // Do optimization if a non dead path exist.
         if (ii->in(1)->bottom_type() != Type::TOP) {
           has_decodeN = true;
-          in_decodeN = ii->in(1);
         }
       } else if (!ii->is_Phi()) {
         may_push = false;
@@ -1809,7 +1806,9 @@
 
     if (has_decodeN && may_push) {
       PhaseIterGVN *igvn = phase->is_IterGVN();
-      PhiNode *new_phi = PhiNode::make_blank(in(0), in_decodeN);
+      // Make narrow type for new phi.
+      const Type* narrow_t = TypeNarrowOop::make(this->bottom_type()->is_ptr());
+      PhiNode* new_phi = new (phase->C, r->req()) PhiNode(r, narrow_t);
       uint orig_cnt = req();
       for (uint i=1; i<req(); ++i) {// For all paths in
         Node *ii = in(i);
@@ -1822,7 +1821,7 @@
           if (ii->as_Phi() == this) {
             new_ii = new_phi;
           } else {
-            new_ii = new (phase->C, 2) EncodePNode(ii, in_decodeN->bottom_type());
+            new_ii = new (phase->C, 2) EncodePNode(ii, narrow_t);
             igvn->register_new_node_with_optimizer(new_ii);
           }
         }