[turbofan]: More optimizations to add and subtract operations on x64

src/compiler/instruction-selector.h

 // Copyright 2014 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.
 
 #ifndef V8_COMPILER_INSTRUCTION_SELECTOR_H_
 #define V8_COMPILER_INSTRUCTION_SELECTOR_H_
 
 #include <deque>
 
 #include "src/compiler/common-operator.h"
@@ skipping 80 matching lines @@
     return Features(CpuFeatures::SupportedFeatures());
   }
 
   // TODO(sigurds) This should take a CpuFeatures argument.
   static MachineOperatorBuilder::Flags SupportedMachineOperatorFlags();
 
   // ===========================================================================
   // ============ Architecture-independent graph covering methods. =============
   // ===========================================================================
 
+  bool ValueOwnedBy(Node* owner, Node* value) const;
+
   // Used in pattern matching during code generation.
   // Check if {node} can be covered while generating code for the current
   // instruction. A node can be covered if the {user} of the node has the only
   // edge and the two are in the same basic block.
   bool CanCover(Node* user, Node* node) const;
 
   // Checks if {node} was already defined, and therefore code was already
   // generated for it.
   bool IsDefined(Node* node) const;
 
@@ skipping 110 matching lines @@
   ZoneDeque<Instruction*> instructions_;
   BoolVector defined_;
   BoolVector used_;
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_INSTRUCTION_SELECTOR_H_