Move JS_VALUE_TYPE ahead of JS_OBJECT_TYPE to save one comparison in

KeyedLoadIC::GenerateGeneric (on IA32), and the same on ARM.
Re-assignmed FIRST_JS_OBJECT_TYPE to JS_VALUE_TYPE.

Also changed JS_OBJECT_TYPE to FIRST_JS_OBJECT_TYPE in several places where
FIRST_JS_OBJECT_TYPE is intended.



git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@113 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/builtins-arm.cc

@@ -106,10 +106,10 @@ void Builtins::Generate_JSConstructCall(MacroAssembler* masm) {
   __ b(eq, &use_receiver);
 
   // If the type of the result (stored in its map) is less than
-  // JS_OBJECT type, it is not an object in the ECMA sense.
+  // FIRST_JS_OBJECT_TYPE, it is not an object in the ECMA sense.
   __ ldr(r2, FieldMemOperand(r0, HeapObject::kMapOffset));
   __ ldrb(r2, FieldMemOperand(r2, Map::kInstanceTypeOffset));
-  __ cmp(r2, Operand(JS_OBJECT_TYPE));
+  __ cmp(r2, Operand(FIRST_JS_OBJECT_TYPE));
   __ b(ge, &exit);
 
   // Throw away the result of the constructor invocation and use the

src/builtins-ia32.cc

@@ -282,10 +282,10 @@ void Builtins::Generate_JSConstructCall(MacroAssembler* masm) {
   __ j(zero, &use_receiver, not_taken);
 
   // If the type of the result (stored in its map) is less than
-  // JS_OBJECT type, it is not an object in the ECMA sense.
+  // FIRST_JS_OBJECT_TYPE, it is not an object in the ECMA sense.
   __ mov(ecx, FieldOperand(eax, HeapObject::kMapOffset));
   __ movzx_b(ecx, FieldOperand(ecx, Map::kInstanceTypeOffset));
-  __ cmp(ecx, JS_OBJECT_TYPE);
+  __ cmp(ecx, FIRST_JS_OBJECT_TYPE);
   __ j(greater_equal, &exit, not_taken);
 
   // Throw away the result of the constructor invocation and use the

src/codegen-arm.cc

@@ -901,18 +901,17 @@ void GetPropertyStub::Generate(MacroAssembler* masm) {
   // Check that the object isn't a smi.
   __ tst(r1, Operand(kSmiTagMask));
   __ b(eq, &slow);
-  // Check that the object is some kind of JS object.
+
+  // Check that the object is some kind of JS object EXCEPT JS Value type.
+  // In the case that the object is a value-wrapper object,
+  // we enter the runtime system to make sure that indexing into string
+  // objects work as intended.
+  ASSERT(JS_OBJECT_TYPE > JS_VALUE_TYPE);
   __ ldr(r2, FieldMemOperand(r1, HeapObject::kMapOffset));
   __ ldrb(r2, FieldMemOperand(r2, Map::kInstanceTypeOffset));
   __ cmp(r2, Operand(JS_OBJECT_TYPE));
   __ b(lt, &slow);
 
-  // Check if the object is a value-wrapper object. In that case we
-  // enter the runtime system to make sure that indexing into string
-  // objects work as intended.
-  __ cmp(r2, Operand(JS_VALUE_TYPE));
-  __ b(eq, &slow);
-
   // Get the elements array of the object.
   __ ldr(r1, FieldMemOperand(r1, JSObject::kElementsOffset));
   // Check that the object is in fast mode (not dictionary).
@@ -979,7 +978,7 @@ void SetPropertyStub::Generate(MacroAssembler* masm) {
   __ cmp(r2, Operand(JS_ARRAY_TYPE));
   __ b(eq, &array);
   // Check that the object is some kind of JS object.
-  __ cmp(r2, Operand(JS_OBJECT_TYPE));
+  __ cmp(r2, Operand(FIRST_JS_OBJECT_TYPE));
   __ b(lt, &slow);
 
 
@@ -2692,7 +2691,7 @@ void ArmCodeGenerator::VisitForInStatement(ForInStatement* node) {
   __ b(eq, &primitive);
   __ ldr(r1, FieldMemOperand(r0, HeapObject::kMapOffset));
   __ ldrb(r1, FieldMemOperand(r1, Map::kInstanceTypeOffset));
-  __ cmp(r1, Operand(JS_OBJECT_TYPE));
+  __ cmp(r1, Operand(FIRST_JS_OBJECT_TYPE));
   __ b(hs, &jsobject);
 
   __ bind(&primitive);

src/codegen-ia32.cc

@@ -905,7 +905,7 @@ void ToBooleanStub::Generate(MacroAssembler* masm) {
   __ j(not_zero, &false_result);
 
   // JavaScript object => true.
-  __ cmp(ecx, JS_OBJECT_TYPE);
+  __ cmp(ecx, FIRST_JS_OBJECT_TYPE);
   __ j(above_equal, &true_result);
 
   // String value => false iff empty.
@@ -2896,7 +2896,7 @@ void Ia32CodeGenerator::VisitForInStatement(ForInStatement* node) {
   __ j(zero, &primitive);
   __ mov(ecx, FieldOperand(eax, HeapObject::kMapOffset));
   __ movzx_b(ecx, FieldOperand(ecx, Map::kInstanceTypeOffset));
-  __ cmp(ecx, JS_OBJECT_TYPE);
+  __ cmp(ecx, FIRST_JS_OBJECT_TYPE);
   __ j(above_equal, &jsobject);
 
   __ bind(&primitive);

src/ic-ia32.cc

@@ -223,7 +223,11 @@ void KeyedLoadIC::GenerateGeneric(MacroAssembler* masm) {
   // Check that the object isn't a smi.
   __ test(ecx, Immediate(kSmiTagMask));
   __ j(zero, &slow, not_taken);
-  // Check that the object is some kind of JS object.
+  // Check that the object is some kind of JS object EXCEPT JS Value type.
+  // In the case that the object is a value-wrapper object,
+  // we enter the runtime system to make sure that indexing
+  // into string objects work as intended.
+  ASSERT(JS_OBJECT_TYPE > JS_VALUE_TYPE);
   __ mov(edx, FieldOperand(ecx, HeapObject::kMapOffset));
   __ movzx_b(edx, FieldOperand(edx, Map::kInstanceTypeOffset));
   __ cmp(edx, JS_OBJECT_TYPE);
@@ -232,11 +236,6 @@ void KeyedLoadIC::GenerateGeneric(MacroAssembler* masm) {
   __ test(eax, Immediate(kSmiTagMask));
   __ j(not_zero, &check_string, not_taken);
   __ sar(eax, kSmiTagSize);
-  // Check if the object is a value-wrapper object. In that case we
-  // enter the runtime system to make sure that indexing into string
-  // objects work as intended.
-  __ cmp(edx, JS_VALUE_TYPE);
-  __ j(equal, &slow, not_taken);
   // Get the elements array of the object.
   __ mov(ecx, FieldOperand(ecx, JSObject::kElementsOffset));
   // Check that the object is in fast mode (not dictionary).
@@ -300,7 +299,7 @@ void KeyedStoreIC::GenerateGeneric(MacroAssembler* masm) {
   __ cmp(ecx, JS_ARRAY_TYPE);
   __ j(equal, &array);
   // Check that the object is some kind of JS object.
-  __ cmp(ecx, JS_OBJECT_TYPE);
+  __ cmp(ecx, FIRST_JS_OBJECT_TYPE);
   __ j(less, &slow, not_taken);
 
 

src/objects-inl.h

@@ -206,7 +206,7 @@ bool Object::IsException() {
 
 bool Object::IsJSObject() {
   return IsHeapObject()
-    && HeapObject::cast(this)->map()->instance_type() >= JS_OBJECT_TYPE;
+    && HeapObject::cast(this)->map()->instance_type() >= FIRST_JS_OBJECT_TYPE;
 }
 
 

src/objects.h

@@ -182,7 +182,7 @@ class PropertyDetails BASE_EMBEDDED {
 // HeapObject::Size, HeapObject::IterateBody, the typeof operator, and
 // Object::IsString.
 //
-// NOTE: Everything following JS_OBJECT_TYPE is considered a
+// NOTE: Everything following JS_VALUE_TYPE is considered a
 // JSObject for GC purposes. The first four entries here have typeof
 // 'object', whereas JS_FUNCTION_TYPE has typeof 'function'.
 #define INSTANCE_TYPE_LIST(V)                   \
@@ -258,10 +258,10 @@ class PropertyDetails BASE_EMBEDDED {
   V(BREAK_POINT_INFO_TYPE)                      \
   V(SCRIPT_TYPE)                                \
                                                 \
+  V(JS_VALUE_TYPE)                              \
   V(JS_OBJECT_TYPE)                             \
   V(JS_GLOBAL_OBJECT_TYPE)                      \
   V(JS_BUILTINS_OBJECT_TYPE)                    \
-  V(JS_VALUE_TYPE)                              \
   V(JS_ARRAY_TYPE)                              \
                                                 \
   V(JS_FUNCTION_TYPE)                           \
@@ -512,10 +512,10 @@ enum InstanceType {
   BREAK_POINT_INFO_TYPE,
   SCRIPT_TYPE,
 
+  JS_VALUE_TYPE,
   JS_OBJECT_TYPE,
   JS_GLOBAL_OBJECT_TYPE,
   JS_BUILTINS_OBJECT_TYPE,
-  JS_VALUE_TYPE,
   JS_ARRAY_TYPE,
 
   JS_FUNCTION_TYPE,
@@ -527,7 +527,7 @@ enum InstanceType {
   // Boundaries for testing the type is a JavaScript "object".  Note that
   // function objects are not counted as objects, even though they are
   // implemented as such; only values whose typeof is "object" are included.
-  FIRST_JS_OBJECT_TYPE = JS_OBJECT_TYPE,
+  FIRST_JS_OBJECT_TYPE = JS_VALUE_TYPE,
   LAST_JS_OBJECT_TYPE = JS_ARRAY_TYPE
 };