Add rotate-right instruction to hydrogen and use it instead of bitwise operations

src/hydrogen-instructions.h

Index: src/hydrogen-instructions.h
diff --git a/src/hydrogen-instructions.h b/src/hydrogen-instructions.h
index dfffe41fca745672ace8ec5ec05774e91de132ed..57fa4363b512341800daa91f27bb2abd711f2d3b 100644
--- a/src/hydrogen-instructions.h
+++ b/src/hydrogen-instructions.h
@@ -153,6 +153,7 @@ class LChunkBuilder;
   V(Random)                                    \
   V(RegExpLiteral)                             \
   V(Return)                                    \
+  V(Ror)                                       \
   V(Sar)                                       \
   V(Shl)                                       \
   V(Shr)                                       \
@@ -897,6 +898,11 @@ class HInstruction: public HValue {
 
   virtual bool IsCall() { return false; }
 
+  bool UnusedAndSafeToDelete() const {
+    bool deleteable_operation = IsBitwiseBinaryOperation();

[ulan, 2012/10/01 18:15:19]

danno, michael: any suggestions for other instruction types to add here?

+    return HasNoUses() && !HasObservableSideEffects() && deleteable_operation;
+  }
+
   DECLARE_ABSTRACT_INSTRUCTION(Instruction)
 
  protected:
@@ -3649,6 +3655,29 @@ class HSar: public HBitwiseBinaryOperation {
 };
 
 
+class HRor: public HBitwiseBinaryOperation {
+ public:
+  HRor(HValue* context, HValue* left, HValue* right)
+      : HBitwiseBinaryOperation(context, left, right) {
+    ChangeRepresentation(Representation::Integer32());
+  }
+
+  virtual Representation RequiredInputRepresentation(int index) {
+    return Representation::Integer32();
+  }
+
+  static HInstruction* NewHRor(Zone* zone,
+                               HValue* context,
+                               HValue* left,
+                               HValue* right);
+
+  DECLARE_CONCRETE_INSTRUCTION(Ror)
+
+ protected:
+  virtual bool DataEquals(HValue* other) { return true; }
+};
+
+
 class HOsrEntry: public HTemplateInstruction<0> {
  public:
   explicit HOsrEntry(BailoutId ast_id) : ast_id_(ast_id) {