Bias commutative single-use register inputs and support lea adds

src/hydrogen-instructions.h

 // Copyright 2012 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 3376 matching lines @@
     observed_input_representation_[0] = Representation::None();
     observed_input_representation_[1] = Representation::None();
   }
 
   HValue* context() { return OperandAt(0); }
   HValue* left() { return OperandAt(1); }
   HValue* right() { return OperandAt(2); }
 
   // TODO(kasperl): Move these helpers to the IA-32 Lithium
   // instruction sequence builder.
-  HValue* LeastConstantOperand() {
-    if (IsCommutative() && left()->IsConstant()) return right();
+  HValue* BetterCandidateForRegisterOperand() {
+    if (IsCommutative()) {
+      if (left()->IsConstant()) return right();
+      if (right()->IsConstant()) return left();
+      if (right()->UseCount() == 1) return right();
+    }
     return left();
   }
 
-  HValue* MostConstantOperand() {
-    if (IsCommutative() && left()->IsConstant()) return left();
+  HValue* WorseCandidateForRegisterOperand() {
+    if (IsCommutative()) {
+      if (left()->IsConstant()) return left();
+      if (right()->IsConstant()) return right();
+      if (right()->UseCount() == 1) return left();
+    }
     return right();
   }
 
   void set_observed_input_representation(int index, Representation rep) {
     ASSERT(index >= 1 && index <= 2);
     observed_input_representation_[index - 1] = rep;
   }
 
   virtual void initialize_output_representation(Representation observed) {
     observed_output_representation_ = observed;
@@ skipping 3143 matching lines @@
   virtual bool IsDeletable() const { return true; }
 };
 
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_