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

src/x64/full-codegen-x64.cc

Index: src/x64/full-codegen-x64.cc
diff --git a/src/x64/full-codegen-x64.cc b/src/x64/full-codegen-x64.cc
index 6b3f45f9b371453ec4753a46151b4015343015da..e0d9bd7feb22baa9626be588b457dc12597fdcf4 100644
--- a/src/x64/full-codegen-x64.cc
+++ b/src/x64/full-codegen-x64.cc
@@ -2630,20 +2630,24 @@ void FullCodeGenerator::EmitClassOf(ZoneList<Expression*>* args) {
 
   // Check that the object is a JS object but take special care of JS
   // functions to make sure they have 'Function' as their class.
+  // Assume that there are only two callable types, and one of them is at
+  // either end of the type range for JS object types. Saves extra comparisons.
+  STATIC_ASSERT(NUM_OF_CALLABLE_SPEC_OBJECT_TYPES == 2);
   __ CmpObjectType(rax, FIRST_SPEC_OBJECT_TYPE, rax);
   // Map is now in rax.
   __ j(below, &null);
-
-  // 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);
-  __ CmpInstanceType(rax, FIRST_CALLABLE_SPEC_OBJECT_TYPE);
-  __ j(above_equal, &function);
-
-  // Check if the constructor in the map is a function.
+  STATIC_ASSERT(FIRST_NONCALLABLE_SPEC_OBJECT_TYPE ==
+                FIRST_SPEC_OBJECT_TYPE + 1);
+  __ j(equal, &function);
+
+  __ CmpInstanceType(rax, LAST_SPEC_OBJECT_TYPE);
+  STATIC_ASSERT(LAST_NONCALLABLE_SPEC_OBJECT_TYPE ==
+                LAST_SPEC_OBJECT_TYPE - 1);
+  __ j(equal, &function);
+  // Assume that there is no larger type.
+  STATIC_ASSERT(LAST_NONCALLABLE_SPEC_OBJECT_TYPE == LAST_TYPE - 1);
+
+  // Check if the constructor in the map is a JS function.
   __ movq(rax, FieldOperand(rax, Map::kConstructorOffset));
   __ CmpObjectType(rax, JS_FUNCTION_TYPE, rbx);
   __ j(not_equal, &non_function_constructor);
@@ -3963,9 +3967,11 @@ void FullCodeGenerator::EmitLiteralCompareTypeof(Expression* expr,
     Split(not_zero, if_true, if_false, fall_through);
   } else if (check->Equals(isolate()->heap()->function_symbol())) {
     __ JumpIfSmi(rax, if_false);
-    STATIC_ASSERT(LAST_CALLABLE_SPEC_OBJECT_TYPE == LAST_TYPE);
-    __ CmpObjectType(rax, FIRST_CALLABLE_SPEC_OBJECT_TYPE, rdx);
-    Split(above_equal, if_true, if_false, fall_through);
+    STATIC_ASSERT(NUM_OF_CALLABLE_SPEC_OBJECT_TYPES == 2);
+    __ CmpObjectType(rax, JS_FUNCTION_TYPE, rdx);
+    __ j(equal, if_true);
+    __ CmpInstanceType(rdx, JS_FUNCTION_PROXY_TYPE);
+    Split(equal, if_true, if_false, fall_through);
   } else if (check->Equals(isolate()->heap()->object_symbol())) {
     __ JumpIfSmi(rax, if_false);
     if (!FLAG_harmony_typeof) {