Reorganize object type enum, such that proxies are no longer in the middle

src/x64/lithium-codegen-x64.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1734 matching lines @@
   EmitBranch(true_block, false_block, equal);
 }
 
 
 // Branches to a label or falls through with the answer in the z flag.
 // Trashes the temp register and possibly input (if it and temp are aliased).
 void LCodeGen::EmitClassOfTest(Label* is_true,
                                Label* is_false,
                                Handle<String> class_name,
                                Register input,
-                               Register temp) {
+                               Register temp,
+                               Register scratch) {
   __ JumpIfSmi(input, is_false);
-  __ CmpObjectType(input, FIRST_SPEC_OBJECT_TYPE, temp);
-  __ j(below, is_false);
 
-  // Map is now in temp.
-  // Functions have class 'Function'.
-  __ CmpInstanceType(temp, FIRST_CALLABLE_SPEC_OBJECT_TYPE);
   if (class_name->IsEqualTo(CStrVector("Function"))) {
-    __ j(above_equal, 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);
+    __ CmpObjectType(input, FIRST_SPEC_OBJECT_TYPE, temp);
+    __ j(below, is_false);
+    __ j(equal, is_true);
+    __ CmpInstanceType(temp, LAST_SPEC_OBJECT_TYPE);
+    __ j(equal, is_true);
   } else {
-    __ j(above_equal, 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.
+    __ movq(temp, FieldOperand(input, HeapObject::kMapOffset));
+    __ movq(scratch, FieldOperand(temp, Map::kInstanceTypeOffset));
+    __ subb(scratch, Immediate(FIRST_NONCALLABLE_SPEC_OBJECT_TYPE));
+    __ cmpb(scratch,
+            Immediate(static_cast<int8_t>(LAST_NONCALLABLE_SPEC_OBJECT_TYPE -
+                                          FIRST_NONCALLABLE_SPEC_OBJECT_TYPE)));
+    __ j(above, is_false);
   }
 
+  // Now we are in the FIRST-LAST_NONCALLABLE_SPEC_OBJECT_TYPE range.
   // Check if the constructor in the map is a function.
   __ movq(temp, FieldOperand(temp, Map::kConstructorOffset));
 
-  // As long as LAST_CALLABLE_SPEC_OBJECT_TYPE is the last 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'.
   __ CmpObjectType(temp, JS_FUNCTION_TYPE, kScratchRegister);
   if (class_name->IsEqualTo(CStrVector("Object"))) {
     __ j(not_equal, is_true);
   } else {
     __ j(not_equal, is_false);
   }
 
   // temp now contains the constructor function. Grab the
   // instance class name from there.
   __ movq(temp, FieldOperand(temp, JSFunction::kSharedFunctionInfoOffset));
   __ movq(temp, FieldOperand(temp,
                              SharedFunctionInfo::kInstanceClassNameOffset));
   // The class name we are testing against is a symbol because it's a literal.
   // The name in the constructor is a symbol because of the way the context is
   // booted.  This routine isn't expected to work for random API-created
   // classes and it doesn't have to because you can't access it with natives
   // syntax.  Since both sides are symbols it is sufficient to use an identity
   // comparison.
   ASSERT(class_name->IsSymbol());
   __ Cmp(temp, class_name);
   // End with the answer in the z flag.
 }
 
 
 void LCodeGen::DoClassOfTestAndBranch(LClassOfTestAndBranch* instr) {
   Register input = ToRegister(instr->InputAt(0));
   Register temp = ToRegister(instr->TempAt(0));
+  Register temp2 = ToRegister(instr->TempAt(1));
   Handle<String> class_name = instr->hydrogen()->class_name();
 
   int true_block = chunk_->LookupDestination(instr->true_block_id());
   int false_block = chunk_->LookupDestination(instr->false_block_id());
 
   Label* true_label = chunk_->GetAssemblyLabel(true_block);
   Label* false_label = chunk_->GetAssemblyLabel(false_block);
 
-  EmitClassOfTest(true_label, false_label, class_name, input, temp);
+  EmitClassOfTest(true_label, false_label, class_name, input, temp, temp2);
 
   EmitBranch(true_block, false_block, equal);
 }
 
 
 void LCodeGen::DoCmpMapAndBranch(LCmpMapAndBranch* instr) {
   Register reg = ToRegister(instr->InputAt(0));
   int true_block = instr->true_block_id();
   int false_block = instr->false_block_id();
 
@@ skipping 2148 matching lines @@
     __ CompareRoot(input, Heap::kUndefinedValueRootIndex);
     __ j(equal, true_label);
     __ JumpIfSmi(input, false_label);
     // Check for undetectable objects => true.
     __ movq(input, FieldOperand(input, HeapObject::kMapOffset));
     __ testb(FieldOperand(input, Map::kBitFieldOffset),
              Immediate(1 << Map::kIsUndetectable));
     final_branch_condition = not_zero;
 
   } else if (type_name->Equals(heap()->function_symbol())) {
+    STATIC_ASSERT(NUM_OF_CALLABLE_SPEC_OBJECT_TYPES == 2);
     __ JumpIfSmi(input, false_label);
-    __ CmpObjectType(input, FIRST_CALLABLE_SPEC_OBJECT_TYPE, input);
-    final_branch_condition = above_equal;
+    __ CmpObjectType(input, JS_FUNCTION_TYPE, input);
+    __ j(equal, true_label);
+    __ CmpInstanceType(input, JS_FUNCTION_PROXY_TYPE);
+    final_branch_condition = equal;
 
   } else if (type_name->Equals(heap()->object_symbol())) {
     __ JumpIfSmi(input, false_label);
     if (!FLAG_harmony_typeof) {
       __ CompareRoot(input, Heap::kNullValueRootIndex);
       __ j(equal, true_label);
     }
     __ CmpObjectType(input, FIRST_NONCALLABLE_SPEC_OBJECT_TYPE, input);
     __ j(below, false_label);
     __ CmpInstanceType(input, LAST_NONCALLABLE_SPEC_OBJECT_TYPE);
@@ skipping 151 matching lines @@
   RegisterEnvironmentForDeoptimization(environment);
   ASSERT(osr_pc_offset_ == -1);
   osr_pc_offset_ = masm()->pc_offset();
 }
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64