Revert of [es5] Class of object is "Function" if object has [[Call]].

src/arm64/lithium-codegen-arm64.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/arm64/frames-arm64.h"
 #include "src/arm64/lithium-codegen-arm64.h"
 #include "src/arm64/lithium-gap-resolver-arm64.h"
 #include "src/base/bits.h"
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
@@ skipping 2337 matching lines @@
   Handle<String> class_name = instr->hydrogen()->class_name();
   Label* true_label = instr->TrueLabel(chunk_);
   Label* false_label = instr->FalseLabel(chunk_);
   Register input = ToRegister(instr->value());
   Register scratch1 = ToRegister(instr->temp1());
   Register scratch2 = ToRegister(instr->temp2());
 
   __ JumpIfSmi(input, false_label);
 
   Register map = scratch2;
-  STATIC_ASSERT(LAST_JS_RECEIVER_TYPE == LAST_TYPE);
-  __ CompareObjectType(input, map, scratch1, FIRST_JS_RECEIVER_TYPE);
-  __ B(lt, false_label);
+  if (String::Equals(isolate()->factory()->Function_string(), class_name)) {
+    // 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);
 
-  // Objects with [[Call]] have class 'Function'.
-  Register bit_field = scratch1;
-  __ Ldrb(bit_field, FieldMemOperand(map, Map::kBitFieldOffset));
-  __ Tst(bit_field, 1 << Map::kIsCallable);
-  if (String::Equals(isolate()->factory()->Function_string(), class_name)) {
-    __ B(ne, true_label);
+    // We expect CompareObjectType to load the object instance type in scratch1.
+    __ CompareObjectType(input, map, scratch1, FIRST_SPEC_OBJECT_TYPE);
+    __ B(lt, false_label);
+    __ B(eq, true_label);
+    __ Cmp(scratch1, LAST_SPEC_OBJECT_TYPE);
+    __ B(eq, true_label);
   } else {
-    __ B(ne, false_label);
+    __ IsObjectJSObjectType(input, map, scratch1, false_label);
   }
 
-  // Now we are in the FIRST-LAST_JS_RECEIVER_TYPE range.
+  // Now we are in the FIRST-LAST_NONCALLABLE_SPEC_OBJECT_TYPE range.
   // Check if the constructor in the map is a function.
   {
     UseScratchRegisterScope temps(masm());
     Register instance_type = temps.AcquireX();
     __ GetMapConstructor(scratch1, map, scratch2, instance_type);
     __ Cmp(instance_type, JS_FUNCTION_TYPE);
   }
   // Objects with a non-function constructor have class 'Object'.
   if (String::Equals(class_name, isolate()->factory()->Object_string())) {
     __ B(ne, true_label);
@@ skipping 3659 matching lines @@
   Handle<ScopeInfo> scope_info = instr->scope_info();
   __ Push(scope_info);
   __ Push(ToRegister(instr->function()));
   CallRuntime(Runtime::kPushBlockContext, 2, instr);
   RecordSafepoint(Safepoint::kNoLazyDeopt);
 }
 
 
 }  // namespace internal
 }  // namespace v8