Reorganize object type enum, such that proxies are no longer in the middle

src/arm/lithium-codegen-arm.cc

Index: src/arm/lithium-codegen-arm.cc
diff --git a/src/arm/lithium-codegen-arm.cc b/src/arm/lithium-codegen-arm.cc
index 03ea929d88ffb0fde58ccf6f718cd48997501e89..772af03531718b5aec262728a7094a317cc4771e 100644
--- a/src/arm/lithium-codegen-arm.cc
+++ b/src/arm/lithium-codegen-arm.cc
@@ -1919,26 +1919,35 @@ void LCodeGen::EmitClassOfTest(Label* is_true,
   __ JumpIfSmi(input, is_false);
   __ CompareObjectType(input, temp, temp2, FIRST_SPEC_OBJECT_TYPE);
   __ b(lt, is_false);
+  ASSERT(LAST_SPEC_OBJECT_TYPE == LAST_TYPE);

[Kevin Millikin (Chromium), 2011/09/07 10:13:12]

This could be a static assert?

[rossberg, 2011/09/07 14:57:31]

Done.

 
-  // Map is now in temp.
+  // Assuming the following assertions, we can do the same test for
+  // either "Object" or "Function", only the branch conditions differ.
+  STATIC_ASSERT(NUM_OF_CALLABLE_SPEC_OBJECT_TYPES == 2);
+  STATIC_ASSERT(FIRST_NONCALLABLE_SPEC_OBJECT_TYPE ==
+                FIRST_SPEC_OBJECT_TYPE + 1);
+  STATIC_ASSERT(LAST_NONCALLABLE_SPEC_OBJECT_TYPE ==
+                LAST_SPEC_OBJECT_TYPE - 1);
+
+  // Map is now in temp, type in temp2.
   // Functions have class 'Function'.
-  __ CompareInstanceType(temp, temp2, FIRST_CALLABLE_SPEC_OBJECT_TYPE);
+  __ cmp(temp2, Operand(FIRST_SPEC_OBJECT_TYPE));

[Kevin Millikin (Chromium), 2011/09/07 10:13:12]

Aren't the flags still set from the previous compare?  You could do something
like:

__ CompareObjectType(...)
if (..."Function"...) {
  __ b(lt, is_false);
  __ b(eq, is_true);
} else {
  __ b(le, is_false);
}
?

[rossberg, 2011/09/07 14:57:31]

Of course. That was the whole intent of the ordering I chose, and I overlooked
to take advantage of it here. 8-}

+  if (class_name->IsEqualTo(CStrVector("Function"))) {
+    __ b(eq, is_true);
+  } else {
+    __ b(le, is_false);
+  }
+  __ cmp(temp2, Operand(LAST_SPEC_OBJECT_TYPE));
   if (class_name->IsEqualTo(CStrVector("Function"))) {
-    __ b(ge, is_true);
+    __ b(eq, is_true);
   } else {
     __ b(ge, is_false);
   }
 
+  // Now we are in the FIRST-LAST_NONCALLABLE_SPEC_OBJECT_TYPE range.
   // Check if the constructor in the map is a function.
   __ ldr(temp, FieldMemOperand(temp, Map::kConstructorOffset));
 
-  // As long as LAST_CALLABLE_SPEC_OBJECT_TYPE is the last instance type and
-  // FIRST_CALLABLE_SPEC_OBJECT_TYPE comes right after
-  // LAST_NONCALLABLE_SPEC_OBJECT_TYPE, we can avoid checking for the latter.
-  STATIC_ASSERT(LAST_TYPE == LAST_CALLABLE_SPEC_OBJECT_TYPE);
-  STATIC_ASSERT(FIRST_CALLABLE_SPEC_OBJECT_TYPE ==
-                LAST_NONCALLABLE_SPEC_OBJECT_TYPE + 1);
-
   // Objects with a non-function constructor have class 'Object'.
   __ CompareObjectType(temp, temp2, temp2, JS_FUNCTION_TYPE);
   if (class_name->IsEqualTo(CStrVector("Object"))) {
@@ -4342,10 +4351,12 @@ Condition LCodeGen::EmitTypeofIs(Label* true_label,
     final_branch_condition = ne;
 
   } else if (type_name->Equals(heap()->function_symbol())) {
+    STATIC_ASSERT(NUM_OF_CALLABLE_SPEC_OBJECT_TYPES == 2);
     __ JumpIfSmi(input, false_label);
-    __ CompareObjectType(input, input, scratch,
-                         FIRST_CALLABLE_SPEC_OBJECT_TYPE);
-    final_branch_condition = ge;
+    __ CompareObjectType(input, scratch, input, JS_FUNCTION_TYPE);
+    __ b(eq, true_label);
+    __ cmp(input, Operand(JS_FUNCTION_PROXY_TYPE));
+    final_branch_condition = eq;
 
   } else if (type_name->Equals(heap()->object_symbol())) {
     __ JumpIfSmi(input, false_label);