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

src/full-codegen/mips/full-codegen-mips.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_MIPS
 
 // Note on Mips implementation:
 //
 // The result_register() for mips is the 'v0' register, which is defined
 // by the ABI to contain function return values. However, the first
@@ skipping 4979 matching lines @@
     __ LoadRoot(at, Heap::kUndefinedValueRootIndex);
     __ Branch(if_true, eq, v0, Operand(at));
     __ JumpIfSmi(v0, if_false);
     // Check for undetectable objects => true.
     __ lw(v0, FieldMemOperand(v0, HeapObject::kMapOffset));
     __ lbu(a1, FieldMemOperand(v0, Map::kBitFieldOffset));
     __ And(a1, a1, Operand(1 << Map::kIsUndetectable));
     Split(ne, a1, Operand(zero_reg), if_true, if_false, fall_through);
   } else if (String::Equals(check, factory->function_string())) {
     __ JumpIfSmi(v0, if_false);
-    STATIC_ASSERT(NUM_OF_CALLABLE_SPEC_OBJECT_TYPES == 2);
-    __ GetObjectType(v0, v0, a1);
-    __ Branch(if_true, eq, a1, Operand(JS_FUNCTION_TYPE));
-    Split(eq, a1, Operand(JS_FUNCTION_PROXY_TYPE),
-          if_true, if_false, fall_through);
+    __ lw(v0, FieldMemOperand(v0, HeapObject::kMapOffset));
+    __ lbu(a1, FieldMemOperand(v0, Map::kBitFieldOffset));
+    __ And(a1, a1,
+           Operand((1 << Map::kIsCallable) | (1 << Map::kIsUndetectable)));
+    Split(eq, a1, Operand(1 << Map::kIsCallable), if_true, if_false,
+          fall_through);
   } else if (String::Equals(check, factory->object_string())) {
     __ JumpIfSmi(v0, if_false);
     __ LoadRoot(at, Heap::kNullValueRootIndex);
     __ Branch(if_true, eq, v0, Operand(at));
-    // Check for JS objects => true.
+    STATIC_ASSERT(LAST_SPEC_OBJECT_TYPE == LAST_TYPE);
     __ GetObjectType(v0, v0, a1);
-    __ Branch(if_false, lt, a1, Operand(FIRST_NONCALLABLE_SPEC_OBJECT_TYPE));
-    __ lbu(a1, FieldMemOperand(v0, Map::kInstanceTypeOffset));
-    __ Branch(if_false, gt, a1, Operand(LAST_NONCALLABLE_SPEC_OBJECT_TYPE));
-    // Check for undetectable objects => false.
+    __ Branch(if_false, lt, a1, Operand(FIRST_SPEC_OBJECT_TYPE));
+    // Check for callable or undetectable objects => false.
     __ lbu(a1, FieldMemOperand(v0, Map::kBitFieldOffset));
-    __ And(a1, a1, Operand(1 << Map::kIsUndetectable));
+    __ And(a1, a1,
+           Operand((1 << Map::kIsCallable) | (1 << Map::kIsUndetectable)));
     Split(eq, a1, Operand(zero_reg), if_true, if_false, fall_through);
 // clang-format off
 #define SIMD128_TYPE(TYPE, Type, type, lane_count, lane_type)    \
   } else if (String::Equals(check, factory->type##_string())) {  \
     __ JumpIfSmi(v0, if_false);                                  \
     __ lw(v0, FieldMemOperand(v0, HeapObject::kMapOffset));      \
     __ LoadRoot(at, Heap::k##Type##MapRootIndex);                \
     Split(eq, v0, Operand(at), if_true, if_false, fall_through);
   SIMD128_TYPES(SIMD128_TYPE)
 #undef SIMD128_TYPE
@@ skipping 294 matching lines @@
          reinterpret_cast<uint32_t>(
              isolate->builtins()->OsrAfterStackCheck()->entry()));
   return OSR_AFTER_STACK_CHECK;
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_MIPS