Support polymorphic loads of constant functions as well as fields.

src/x64/lithium-codegen-x64.cc

Index: src/x64/lithium-codegen-x64.cc
diff --git a/src/x64/lithium-codegen-x64.cc b/src/x64/lithium-codegen-x64.cc
index 5b45b136e715058843daac836f282d3d1876e1f5..47c77b7e0a812a73d2b40ce04f5e48ef74af38cb 100644
--- a/src/x64/lithium-codegen-x64.cc
+++ b/src/x64/lithium-codegen-x64.cc
@@ -2208,23 +2208,29 @@ void LCodeGen::DoLoadNamedField(LLoadNamedField* instr) {
 }
 
 
-void LCodeGen::EmitLoadField(Register result,
-                             Register object,
-                             Handle<Map> type,
-                             Handle<String> name) {
+void LCodeGen::EmitLoadFieldOrConstantFunction(Register result,
+                                               Register object,
+                                               Handle<Map> type,
+                                               Handle<String> name) {
   LookupResult lookup;
   type->LookupInDescriptors(NULL, *name, &lookup);
-  ASSERT(lookup.IsProperty() && lookup.type() == FIELD);
-  int index = lookup.GetLocalFieldIndexFromMap(*type);
-  int offset = index * kPointerSize;
-  if (index < 0) {
-    // Negative property indices are in-object properties, indexed
-    // from the end of the fixed part of the object.
-    __ movq(result, FieldOperand(object, offset + type->instance_size()));
+  ASSERT(lookup.IsProperty() &&
+         (lookup.type() == FIELD || lookup.type() == CONSTANT_FUNCTION));
+  if (lookup.type() == FIELD) {
+    int index = lookup.GetLocalFieldIndexFromMap(*type);
+    int offset = index * kPointerSize;
+    if (index < 0) {
+      // Negative property indices are in-object properties, indexed
+      // from the end of the fixed part of the object.
+      __ movq(result, FieldOperand(object, offset + type->instance_size()));
+    } else {
+      // Non-negative property indices are in the properties array.
+      __ movq(result, FieldOperand(object, JSObject::kPropertiesOffset));
+      __ movq(result, FieldOperand(result, offset + FixedArray::kHeaderSize));
+    }
   } else {
-    // Non-negative property indices are in the properties array.
-    __ movq(result, FieldOperand(object, JSObject::kPropertiesOffset));
-    __ movq(result, FieldOperand(result, offset + FixedArray::kHeaderSize));
+    Handle<JSFunction> function(lookup.GetConstantFunctionFromMap(*type));
+    LoadHeapObject(result, Handle<HeapObject>::cast(function));
   }
 }
 
@@ -2248,7 +2254,7 @@ void LCodeGen::DoLoadNamedFieldPolymorphic(LLoadNamedFieldPolymorphic* instr) {
       NearLabel next;
       __ Cmp(FieldOperand(object, HeapObject::kMapOffset), map);
       __ j(not_equal, &next);
-      EmitLoadField(result, object, map, name);
+      EmitLoadFieldOrConstantFunction(result, object, map, name);
       __ jmp(&done);
       __ bind(&next);
     }
@@ -2257,7 +2263,7 @@ void LCodeGen::DoLoadNamedFieldPolymorphic(LLoadNamedFieldPolymorphic* instr) {
     if (instr->hydrogen()->need_generic()) {
       NearLabel generic;
       __ j(not_equal, &generic);
-      EmitLoadField(result, object, map, name);
+      EmitLoadFieldOrConstantFunction(result, object, map, name);
       __ jmp(&done);
       __ bind(&generic);
       __ Move(rcx, instr->hydrogen()->name());
@@ -2265,7 +2271,7 @@ void LCodeGen::DoLoadNamedFieldPolymorphic(LLoadNamedFieldPolymorphic* instr) {
       CallCode(ic, RelocInfo::CODE_TARGET, instr);
     } else {
       DeoptimizeIf(not_equal, instr->environment());
-      EmitLoadField(result, object, map, name);
+      EmitLoadFieldOrConstantFunction(result, object, map, name);
     }
     __ bind(&done);
   }