Calls to HCheckFunction can be eliminated if the value is an HConstant.

src/hydrogen-instructions.h

Index: src/hydrogen-instructions.h
diff --git a/src/hydrogen-instructions.h b/src/hydrogen-instructions.h
index 27c517aa1a5be38b03e3ec186532dea8da7aeebb..48eb217ecd02cde4038f493f1587a3f21c9adeed 100644
--- a/src/hydrogen-instructions.h
+++ b/src/hydrogen-instructions.h
@@ -2837,6 +2837,8 @@ class HCheckFunction: public HUnaryOperation {
   virtual void PrintDataTo(StringStream* stream);
   virtual HType CalculateInferredType();
 
+  virtual HValue* Canonicalize();
+
 #ifdef DEBUG
   virtual void Verify();
 #endif
@@ -3410,6 +3412,11 @@ class HConstant: public HTemplateInstruction<0> {
     }
   }
 
+  bool UniqueValueIdsMatch(UniqueValueId other) {
+    if (!has_double_value_) return unique_id_ == other;

[Sven Panne, 2013/07/17 08:09:56]

return !has_double_value_ && unique_id_ == other;

[mvstanton, 2013/07/17 08:45:46]

Done.

+    return false;
+  }
+
 #ifdef DEBUG
   virtual void Verify() { }
 #endif