--- a/src/share/vm/adlc/output_c.cpp	Fri Jan 29 09:27:22 2010 -0800
+++ b/src/share/vm/adlc/output_c.cpp	Fri Jan 29 22:51:41 2010 -0800
@@ -1,5 +1,5 @@
 /*
- * Copyright 1998-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 1998-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -1496,7 +1496,7 @@
   unsigned      i;
 
   // Generate Expand function header
-  fprintf(fp,"MachNode *%sNode::Expand(State *state, Node_List &proj_list) {\n", node->_ident);
+  fprintf(fp,"MachNode *%sNode::Expand(State *state, Node_List &proj_list, Node* mem) {\n", node->_ident);
   fprintf(fp,"Compile* C = Compile::current();\n");
   // Generate expand code
   if( node->expands() ) {
@@ -1546,15 +1546,16 @@
     // Build a mapping from operand index to input edges
     fprintf(fp,"  unsigned idx0 = oper_input_base();\n");
 
-    // The order in which inputs are added to a node is very
+    // The order in which the memory input is added to a node is very
     // strange.  Store nodes get a memory input before Expand is
-    // called and all other nodes get it afterwards so
-    // oper_input_base is wrong during expansion.  This code adjusts
-    // is so that expansion will work correctly.
-    bool missing_memory_edge = node->_matrule->needs_ideal_memory_edge(_globalNames) &&
-                               node->is_ideal_store() == Form::none;
-    if (missing_memory_edge) {
-      fprintf(fp,"  idx0--; // Adjust base because memory edge hasn't been inserted yet\n");
+    // called and other nodes get it afterwards or before depending on
+    // match order so oper_input_base is wrong during expansion.  This
+    // code adjusts it so that expansion will work correctly.
+    int has_memory_edge = node->_matrule->needs_ideal_memory_edge(_globalNames);
+    if (has_memory_edge) {
+      fprintf(fp,"  if (mem == (Node*)1) {\n");
+      fprintf(fp,"    idx0--; // Adjust base because memory edge hasn't been inserted yet\n");
+      fprintf(fp,"  }\n");
     }
 
     for( i = 0; i < node->num_opnds(); i++ ) {
@@ -1611,9 +1612,11 @@
         int node_mem_op = node->memory_operand(_globalNames);
         assert( node_mem_op != InstructForm::NO_MEMORY_OPERAND,
                 "expand rule member needs memory but top-level inst doesn't have any" );
-        if (!missing_memory_edge) {
+        if (has_memory_edge) {
           // Copy memory edge
-          fprintf(fp,"  n%d->add_req(_in[1]);\t// Add memory edge\n", cnt);
+          fprintf(fp,"  if (mem != (Node*)1) {\n");
+          fprintf(fp,"    n%d->add_req(_in[1]);\t// Add memory edge\n", cnt);
+          fprintf(fp,"  }\n");
         }
       }
 
@@ -1689,7 +1692,7 @@
       } // done iterating over a new instruction's operands
 
       // Invoke Expand() for the newly created instruction.
-      fprintf(fp,"  result = n%d->Expand( state, proj_list );\n", cnt);
+      fprintf(fp,"  result = n%d->Expand( state, proj_list, mem );\n", cnt);
       assert( !new_inst->expands(), "Do not have complete support for recursive expansion");
     } // done iterating over new instructions
     fprintf(fp,"\n");

--- a/src/share/vm/adlc/output_h.cpp	Fri Jan 29 09:27:22 2010 -0800
+++ b/src/share/vm/adlc/output_h.cpp	Fri Jan 29 22:51:41 2010 -0800
@@ -1,5 +1,5 @@
 /*
- * Copyright 1998-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 1998-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -1754,7 +1754,7 @@
         instr->has_temps() ||
         instr->_matrule != NULL &&
         instr->num_opnds() != instr->num_unique_opnds() ) {
-      fprintf(fp,"  virtual MachNode      *Expand(State *state, Node_List &proj_list);\n");
+      fprintf(fp,"  virtual MachNode      *Expand(State *state, Node_List &proj_list, Node* mem);\n");
     }
 
     if (instr->is_pinned(_globalNames)) {

--- a/src/share/vm/opto/machnode.hpp	Fri Jan 29 09:27:22 2010 -0800
+++ b/src/share/vm/opto/machnode.hpp	Fri Jan 29 22:51:41 2010 -0800
@@ -1,5 +1,5 @@
 /*
- * Copyright 1997-2007 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 1997-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -232,7 +232,7 @@
   // Expand method for MachNode, replaces nodes representing pseudo
   // instructions with a set of nodes which represent real machine
   // instructions and compute the same value.
-  virtual MachNode *Expand( State *, Node_List &proj_list ) { return this; }
+  virtual MachNode *Expand( State *, Node_List &proj_list, Node* mem ) { return this; }
 
   // Bottom_type call; value comes from operand0
   virtual const class Type *bottom_type() const { return _opnds[0]->type(); }

--- a/src/share/vm/opto/matcher.cpp	Fri Jan 29 09:27:22 2010 -0800
+++ b/src/share/vm/opto/matcher.cpp	Fri Jan 29 22:51:41 2010 -0800
@@ -1,5 +1,5 @@
 /*
- * Copyright 1997-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 1997-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -1580,7 +1580,7 @@
   uint num_proj = _proj_list.size();
 
   // Perform any 1-to-many expansions required
-  MachNode *ex = mach->Expand(s,_proj_list);
+  MachNode *ex = mach->Expand(s,_proj_list, mem);
   if( ex != mach ) {
     assert(ex->ideal_reg() == mach->ideal_reg(), "ideal types should match");
     if( ex->in(1)->is_Con() )

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/compiler/6916644/Test6916644.java	Fri Jan 29 22:51:41 2010 -0800
@@ -0,0 +1,50 @@
+/*
+ * Copyright 2010 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+/**
+ * @test
+ * @bug 6916644
+ * @summary C2 compiler crash on x86
+ *
+ * @run main/othervm -Xcomp -XX:CompileOnly=Test6916644.test Test6916644
+ */
+
+public class Test6916644 {
+    static int result;
+    static int i1;
+    static int i2;
+
+    static public void test(double d) {
+        result = (d <= 0.0D) ? i1 : i2;
+    }
+
+    public static void main(String[] args) {
+        for (int i = 0; i < 100000; i++) {
+            // use an alternating value so the test doesn't always go
+            // the same direction.  Otherwise we won't transform it
+            // into a cmove.
+            test(i & 1);
+        }
+    }
+}