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

src/full-codegen/ia32/full-codegen-ia32.cc

Index: src/full-codegen/ia32/full-codegen-ia32.cc
diff --git a/src/full-codegen/ia32/full-codegen-ia32.cc b/src/full-codegen/ia32/full-codegen-ia32.cc
index 2272e73f8421cc9153f44cc95cf304d0f22b3304..fab491b61f49e11b833e0db668d99cbc5fd82382 100644
--- a/src/full-codegen/ia32/full-codegen-ia32.cc
+++ b/src/full-codegen/ia32/full-codegen-ia32.cc
@@ -4904,27 +4904,27 @@ void FullCodeGenerator::EmitLiteralCompareTypeof(Expression* expr,
     __ JumpIfSmi(eax, if_false);
     // Check for undetectable objects => true.
     __ mov(edx, FieldOperand(eax, HeapObject::kMapOffset));
-    __ movzx_b(ecx, FieldOperand(edx, Map::kBitFieldOffset));
-    __ test(ecx, Immediate(1 << Map::kIsUndetectable));
+    __ test_b(FieldOperand(edx, Map::kBitFieldOffset),
+              1 << Map::kIsUndetectable);
     Split(not_zero, if_true, if_false, fall_through);
   } else if (String::Equals(check, factory->function_string())) {
     __ JumpIfSmi(eax, if_false);
-    STATIC_ASSERT(NUM_OF_CALLABLE_SPEC_OBJECT_TYPES == 2);
-    __ CmpObjectType(eax, JS_FUNCTION_TYPE, edx);
-    __ j(equal, if_true);
-    __ CmpInstanceType(edx, JS_FUNCTION_PROXY_TYPE);
+    // Check for callable and not undetectable objects => true.
+    __ mov(edx, FieldOperand(eax, HeapObject::kMapOffset));
+    __ movzx_b(ecx, FieldOperand(edx, Map::kBitFieldOffset));
+    __ and_(ecx, (1 << Map::kIsCallable) | (1 << Map::kIsUndetectable));
+    __ cmp(ecx, 1 << Map::kIsCallable);
     Split(equal, if_true, if_false, fall_through);
   } else if (String::Equals(check, factory->object_string())) {
     __ JumpIfSmi(eax, if_false);
     __ cmp(eax, isolate()->factory()->null_value());
     __ j(equal, if_true);
-    __ CmpObjectType(eax, FIRST_NONCALLABLE_SPEC_OBJECT_TYPE, edx);
+    STATIC_ASSERT(LAST_SPEC_OBJECT_TYPE == LAST_TYPE);
+    __ CmpObjectType(eax, FIRST_SPEC_OBJECT_TYPE, edx);
     __ j(below, if_false);
-    __ CmpInstanceType(edx, LAST_NONCALLABLE_SPEC_OBJECT_TYPE);
-    __ j(above, if_false);
-    // Check for undetectable objects => false.
+    // Check for callable or undetectable objects => false.
     __ test_b(FieldOperand(edx, Map::kBitFieldOffset),
-              1 << Map::kIsUndetectable);
+              (1 << Map::kIsCallable) | (1 << Map::kIsUndetectable));
     Split(zero, if_true, if_false, fall_through);
 // clang-format off
 #define SIMD128_TYPE(TYPE, Type, type, lane_count, lane_type)   \