Add an IC for CompareNil operations

src/x64/lithium-codegen-x64.cc

 // Copyright 2013 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 2057 matching lines @@
 void LCodeGen::DoCmpConstantEqAndBranch(LCmpConstantEqAndBranch* instr) {
   Register left = ToRegister(instr->left());
   int true_block = chunk_->LookupDestination(instr->true_block_id());
   int false_block = chunk_->LookupDestination(instr->false_block_id());
 
   __ cmpq(left, Immediate(instr->hydrogen()->right()));
   EmitBranch(true_block, false_block, equal);
 }
 
 
-void LCodeGen::DoIsNilAndBranch(LIsNilAndBranch* instr) {
-  Register reg = ToRegister(instr->value());
-  int false_block = chunk_->LookupDestination(instr->false_block_id());
-
-  // If the expression is known to be untagged or a smi, then it's definitely
-  // not null, and it can't be a an undetectable object.
-  if (instr->hydrogen()->representation().IsSpecialization() ||
-      instr->hydrogen()->type().IsSmi()) {
-    EmitGoto(false_block);
-    return;
-  }
-
-  int true_block = chunk_->LookupDestination(instr->true_block_id());
-  Heap::RootListIndex nil_value = instr->nil() == kNullValue ?
-      Heap::kNullValueRootIndex :
-      Heap::kUndefinedValueRootIndex;
-  __ CompareRoot(reg, nil_value);
-  if (instr->kind() == kStrictEquality) {
-    EmitBranch(true_block, false_block, equal);
-  } else {
-    Heap::RootListIndex other_nil_value = instr->nil() == kNullValue ?
-        Heap::kUndefinedValueRootIndex :
-        Heap::kNullValueRootIndex;
-    Label* true_label = chunk_->GetAssemblyLabel(true_block);
-    Label* false_label = chunk_->GetAssemblyLabel(false_block);
-    __ j(equal, true_label);
-    __ CompareRoot(reg, other_nil_value);
-    __ j(equal, true_label);
-    __ JumpIfSmi(reg, false_label);
-    // Check for undetectable objects by looking in the bit field in
-    // the map. The object has already been smi checked.
-    Register scratch = ToRegister(instr->temp());
-    __ movq(scratch, FieldOperand(reg, HeapObject::kMapOffset));
-    __ testb(FieldOperand(scratch, Map::kBitFieldOffset),
-             Immediate(1 << Map::kIsUndetectable));
-    EmitBranch(true_block, false_block, not_zero);
-  }
-}
-
-
 Condition LCodeGen::EmitIsObject(Register input,
                                  Label* is_not_object,
                                  Label* is_object) {
   ASSERT(!input.is(kScratchRegister));
 
   __ JumpIfSmi(input, is_not_object);
 
   __ CompareRoot(input, Heap::kNullValueRootIndex);
   __ j(equal, is_object);
 
@@ skipping 3533 matching lines @@
                                FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64