Refactor HCheckInstanceType to allow mask/tag tests.

src/hydrogen-instructions.h

Index: src/hydrogen-instructions.h
diff --git a/src/hydrogen-instructions.h b/src/hydrogen-instructions.h
index 5a15839579b84ccc383e97c43950335e0bad42cc..73c46a4403b8a72ddad67077012c8624d33d9608 100644
--- a/src/hydrogen-instructions.h
+++ b/src/hydrogen-instructions.h
@@ -1757,19 +1757,17 @@ class HCheckFunction: public HUnaryOperation {
 
 class HCheckInstanceType: public HUnaryOperation {
  public:
-  // Check that the instance type is in the range [first, last] where
-  // both first and last are included.
-  HCheckInstanceType(HValue* value, InstanceType first, InstanceType last)
-      : HUnaryOperation(value), first_(first), last_(last) {
-    ASSERT(first <= last);
-    set_representation(Representation::Tagged());
-    SetFlag(kUseGVN);
-    if ((FIRST_STRING_TYPE < first && last <= LAST_STRING_TYPE) ||
-        (FIRST_STRING_TYPE <= first && last < LAST_STRING_TYPE)) {
-      // A particular string instance type can change because of GC or
-      // externalization, but the value still remains a string.
-      SetFlag(kDependsOnMaps);
-    }
+  static HCheckInstanceType* NewIsJSObjectOrJSFunction(HValue* value) {
+    return new HCheckInstanceType(value, IS_JS_OBJECT_OR_JS_FUNCTION);
+  }
+  static HCheckInstanceType* NewIsJSArray(HValue* value) {
+    return new HCheckInstanceType(value, IS_JS_ARRAY);
+  }
+  static HCheckInstanceType* NewIsString(HValue* value) {
+    return new HCheckInstanceType(value, IS_STRING);
+  }
+  static HCheckInstanceType* NewIsSymbol(HValue* value) {
+    return new HCheckInstanceType(value, IS_SYMBOL);
   }
 
   virtual bool IsCheckInstruction() const { return true; }
@@ -1785,17 +1783,15 @@ class HCheckInstanceType: public HUnaryOperation {
   virtual HValue* Canonicalize() {
     if (!value()->type().IsUninitialized() &&
         value()->type().IsString() &&
-        first() == FIRST_STRING_TYPE &&
-        last() == LAST_STRING_TYPE) {
+        check_ == IS_STRING) {
       return NULL;
     }
     return this;
   }
 
-  static HCheckInstanceType* NewIsJSObjectOrJSFunction(HValue* value);
-
-  InstanceType first() const { return first_; }
-  InstanceType last() const { return last_; }
+  bool is_interval_check() const { return check_ <= LAST_INTERVAL_CHECK; }
+  void GetCheckInterval(InstanceType* first, InstanceType* last);
+  void GetCheckMaskAndTag(uint8_t* mask, uint8_t* tag);
 
   DECLARE_CONCRETE_INSTRUCTION(CheckInstanceType)
 
@@ -1805,12 +1801,25 @@ class HCheckInstanceType: public HUnaryOperation {
   // with a larger range.
   virtual bool DataEquals(HValue* other) {
     HCheckInstanceType* b = HCheckInstanceType::cast(other);
-    return (first_ == b->first()) && (last_ == b->last());
+    return check_ == b->check_;
   }
 
  private:
-  InstanceType first_;
-  InstanceType last_;
+  enum Check {
+    IS_JS_OBJECT_OR_JS_FUNCTION,
+    IS_JS_ARRAY,
+    IS_STRING,
+    IS_SYMBOL,
+    LAST_INTERVAL_CHECK = IS_JS_ARRAY
+  };
+
+  HCheckInstanceType(HValue* value, Check check)
+      : HUnaryOperation(value), check_(check) {
+    set_representation(Representation::Tagged());
+    SetFlag(kUseGVN);
+  }
+
+  const Check check_;
 };