[es6] Initial steps towards a correct implementation of IsCallable.

src/ia32/lithium-codegen-ia32.cc

 // Copyright 2012 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.
 
 #if V8_TARGET_ARCH_IA32
 
 #include "src/base/bits.h"
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
 #include "src/codegen.h"
@@ skipping 5403 matching lines @@
     __ cmp(input, factory()->undefined_value());
     __ j(equal, true_label, true_distance);
     __ JumpIfSmi(input, false_label, false_distance);
     // Check for undetectable objects => true.
     __ mov(input, FieldOperand(input, HeapObject::kMapOffset));
     __ test_b(FieldOperand(input, Map::kBitFieldOffset),
               1 << Map::kIsUndetectable);
     final_branch_condition = not_zero;
 
   } else if (String::Equals(type_name, factory()->function_string())) {
-    STATIC_ASSERT(NUM_OF_CALLABLE_SPEC_OBJECT_TYPES == 2);
     __ JumpIfSmi(input, false_label, false_distance);
-    __ CmpObjectType(input, JS_FUNCTION_TYPE, input);
-    __ j(equal, true_label, true_distance);
-    __ CmpInstanceType(input, JS_FUNCTION_PROXY_TYPE);
+    // Check for callable and not undetectable objects => true.
+    __ mov(input, FieldOperand(input, HeapObject::kMapOffset));
+    __ movzx_b(input, FieldOperand(input, Map::kBitFieldOffset));
+    __ and_(input, (1 << Map::kIsCallable) | (1 << Map::kIsUndetectable));
+    __ cmp(input, 1 << Map::kIsCallable);
     final_branch_condition = equal;
 
   } else if (String::Equals(type_name, factory()->object_string())) {
     __ JumpIfSmi(input, false_label, false_distance);
     __ cmp(input, factory()->null_value());
     __ j(equal, true_label, true_distance);
-    __ CmpObjectType(input, FIRST_NONCALLABLE_SPEC_OBJECT_TYPE, input);
+    STATIC_ASSERT(LAST_SPEC_OBJECT_TYPE == LAST_TYPE);
+    __ CmpObjectType(input, FIRST_SPEC_OBJECT_TYPE, input);
     __ j(below, false_label, false_distance);
-    __ CmpInstanceType(input, LAST_NONCALLABLE_SPEC_OBJECT_TYPE);
-    __ j(above, false_label, false_distance);
-    // Check for undetectable objects => false.
+    // Check for callable or undetectable objects => false.
     __ test_b(FieldOperand(input, Map::kBitFieldOffset),
-              1 << Map::kIsUndetectable);
+              (1 << Map::kIsCallable) | (1 << Map::kIsUndetectable));
     final_branch_condition = zero;
 
 // clang-format off
 #define SIMD128_TYPE(TYPE, Type, type, lane_count, lane_type)         \
   } else if (String::Equals(type_name, factory()->type##_string())) { \
     __ JumpIfSmi(input, false_label, false_distance);                 \
     __ cmp(FieldOperand(input, HeapObject::kMapOffset),               \
            factory()->type##_map());                                  \
     final_branch_condition = equal;
   SIMD128_TYPES(SIMD128_TYPE)
@@ skipping 298 matching lines @@
   RecordSafepoint(Safepoint::kNoLazyDeopt);
 }
 
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_IA32