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 f5d744914977f3d90a008c1f7f6bc42c06a0ebc2..c88a93ae5c5b11af79a02ef338ea69b1d1c364f7 100644
--- a/src/arm/lithium-codegen-arm.cc
+++ b/src/arm/lithium-codegen-arm.cc
@@ -1918,28 +1918,36 @@ 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);
-  __ CompareObjectType(input, temp, temp2, FIRST_SPEC_OBJECT_TYPE);
-  __ b(lt, is_false);
 
-  // Map is now in temp.
-  // Functions have class 'Function'.
-  __ CompareInstanceType(temp, temp2, FIRST_CALLABLE_SPEC_OBJECT_TYPE);
   if (class_name->IsEqualTo(CStrVector("Function"))) {
-    __ b(ge, 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);
+    __ CompareObjectType(input, temp, temp2, FIRST_SPEC_OBJECT_TYPE);
+    __ b(lt, is_false);
+    __ b(eq, is_true);
+    __ cmp(temp2, Operand(LAST_SPEC_OBJECT_TYPE));
+    __ b(eq, is_true);
   } else {
-    __ b(ge, 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.
+    __ ldr(temp, FieldMemOperand(input, HeapObject::kMapOffset));
+    __ ldrb(temp2, FieldMemOperand(temp, Map::kInstanceTypeOffset));
+    __ sub(temp2, temp2, Operand(FIRST_NONCALLABLE_SPEC_OBJECT_TYPE));
+    __ cmp(temp2, Operand(LAST_NONCALLABLE_SPEC_OBJECT_TYPE -
+                          FIRST_NONCALLABLE_SPEC_OBJECT_TYPE));
+    __ b(gt, 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"))) {
@@ -4343,10 +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);