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

src/ia32/lithium-codegen-ia32.cc

Index: src/ia32/lithium-codegen-ia32.cc
diff --git a/src/ia32/lithium-codegen-ia32.cc b/src/ia32/lithium-codegen-ia32.cc
index 4e3ea98161dd278f177ecf10918fb3262bac2cb2..07709b608a304b6a5ed2bd19fbc0e5acf4203651 100644
--- a/src/ia32/lithium-codegen-ia32.cc
+++ b/src/ia32/lithium-codegen-ia32.cc
@@ -1745,28 +1745,36 @@ void LCodeGen::EmitClassOfTest(Label* is_true,
   ASSERT(!input.is(temp));
   ASSERT(!temp.is(temp2));  // But input and temp2 may be the same register.
   __ JumpIfSmi(input, is_false);
-  __ CmpObjectType(input, FIRST_SPEC_OBJECT_TYPE, temp);
-  __ j(below, is_false);
 
-  // Map is now in temp.
-  // Functions have class 'Function'.
-  __ CmpInstanceType(temp, FIRST_CALLABLE_SPEC_OBJECT_TYPE);
   if (class_name->IsEqualTo(CStrVector("Function"))) {
-    __ j(above_equal, is_true);
+    // Assuming the following assertions, we can use the same compares to test
+    // for both being a function type and being in the object type range.
+    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);
+    STATIC_ASSERT(LAST_SPEC_OBJECT_TYPE == LAST_TYPE);
+    __ CmpObjectType(input, FIRST_SPEC_OBJECT_TYPE, temp);
+    __ j(below, is_false);
+    __ j(equal, is_true);
+    __ CmpInstanceType(temp, LAST_SPEC_OBJECT_TYPE);
+    __ j(equal, is_true);
   } else {
-    __ j(above_equal, is_false);
+    // Faster code path to avoid two compares: subtract lower bound from the
+    // actual type and do a signed compare with the width of the type range.
+    __ mov(temp, FieldOperand(input, HeapObject::kMapOffset));
+    __ mov(temp2, FieldOperand(temp, Map::kInstanceTypeOffset));
+    __ sub(Operand(temp2), Immediate(FIRST_NONCALLABLE_SPEC_OBJECT_TYPE));
+    __ cmpb(Operand(temp2),
+            static_cast<int8_t>(LAST_NONCALLABLE_SPEC_OBJECT_TYPE -
+                                FIRST_NONCALLABLE_SPEC_OBJECT_TYPE));
+    __ j(above, is_false);
   }
 
+  // Now we are in the FIRST-LAST_NONCALLABLE_SPEC_OBJECT_TYPE range.
   // Check if the constructor in the map is a function.
   __ mov(temp, FieldOperand(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'.
   __ CmpObjectType(temp, JS_FUNCTION_TYPE, temp2);
   if (class_name->IsEqualTo(CStrVector("Object"))) {
@@ -4188,10 +4196,12 @@ Condition LCodeGen::EmitTypeofIs(Label* true_label,
     final_branch_condition = not_zero;
 
   } else if (type_name->Equals(heap()->function_symbol())) {
-    STATIC_ASSERT(LAST_TYPE == LAST_CALLABLE_SPEC_OBJECT_TYPE);
+    STATIC_ASSERT(NUM_OF_CALLABLE_SPEC_OBJECT_TYPES == 2);
     __ JumpIfSmi(input, false_label);
-    __ CmpObjectType(input, FIRST_CALLABLE_SPEC_OBJECT_TYPE, input);
-    final_branch_condition = above_equal;
+    __ CmpObjectType(input, JS_FUNCTION_TYPE, input);
+    __ j(equal, true_label);
+    __ CmpInstanceType(input, JS_FUNCTION_PROXY_TYPE);
+    final_branch_condition = equal;
 
   } else if (type_name->Equals(heap()->object_symbol())) {
     __ JumpIfSmi(input, false_label);