Crankshaft support for polymorphic array handling

src/hydrogen-instructions.h

 // Copyright 2011 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 76 matching lines @@
   V(CheckMap)                                  \
   V(CheckNonSmi)                               \
   V(CheckPrototypeMaps)                        \
   V(CheckSmi)                                  \
   V(ClampToUint8)                              \
   V(ClassOfTest)                               \
   V(Compare)                                   \
   V(CompareJSObjectEq)                         \
   V(CompareMap)                                \
   V(CompareSymbolEq)                           \
+  V(CompareWithConstant)                       \
   V(Constant)                                  \
   V(Context)                                   \
   V(DeleteProperty)                            \
   V(Deoptimize)                                \
   V(Div)                                       \
+  V(ElementsKind)                              \
   V(EnterInlined)                              \
   V(ExternalArrayLength)                       \
   V(FixedArrayLength)                          \
   V(ForceRepresentation)                       \
   V(FunctionLiteral)                           \
   V(GetCachedArrayIndex)                       \
   V(GlobalObject)                              \
   V(GlobalReceiver)                            \
   V(Goto)                                      \
   V(HasCachedArrayIndex)                       \
@@ skipping 283 matching lines @@
   enum Type {
     kTagged = 0x1,           // 0000 0000 0000 0001
     kTaggedPrimitive = 0x5,  // 0000 0000 0000 0101
     kTaggedNumber = 0xd,     // 0000 0000 0000 1101
     kSmi = 0x1d,             // 0000 0000 0001 1101
     kHeapNumber = 0x2d,      // 0000 0000 0010 1101
     kString = 0x45,          // 0000 0000 0100 0101
     kBoolean = 0x85,         // 0000 0000 1000 0101
     kNonPrimitive = 0x101,   // 0000 0001 0000 0001
     kJSObject = 0x301,       // 0000 0011 0000 0001
-    kJSArray = 0x701,        // 0000 0111 1000 0001

[fschneider, 2011/06/15 12:11:46]

Accidental edit?

[Jakob Kummerow, 2011/06/15 12:28:58]

Nope. In a drive-by fashion, I noticed that comment and code weren't in sync and
decided to fix the comment.

+    kJSArray = 0x701,        // 0000 0111 0000 0001
     kUninitialized = 0x1fff  // 0001 1111 1111 1111
   };
 
   // Make sure type fits in int16.
   STATIC_ASSERT(kUninitialized < (1 << (2 * kBitsPerByte)));
 
   explicit HType(Type t) : type_(t) { }
 
   int16_t type_;
 };
@@ skipping 61 matching lines @@
 
   // There must be one corresponding kDepends flag for every kChanges flag and
   // the order of the kChanges flags must be exactly the same as of the kDepends
   // flags.
   enum Flag {
     // Declare global value numbering flags.
   #define DECLARE_DO(type) kChanges##type, kDependsOn##type,
     GVN_FLAG_LIST(DECLARE_DO)
   #undef DECLARE_DO
     kFlexibleRepresentation,
-    kUseGVN,
+    kUseGVN,  // Participate in Global Value Numbering, i.e. elimination of

[fschneider, 2011/06/15 12:11:46]

I'd insert the comment in a separate line before kUseGVN.

[Jakob Kummerow, 2011/06/15 12:28:58]

Done.

+    // unnecessary recomputations. If an instruction sets this flag, it must
+    // implement DataEquals(), which will be used to determine if other
+    // occurrences of the instruction are indeed the same.
     kCanOverflow,
     kBailoutOnMinusZero,
     kCanBeDivByZero,
     kDeoptimizeOnUndefined,
     kIsArguments,
     kTruncatingToInt32,
     kLastFlag = kTruncatingToInt32
   };
 
   STATIC_ASSERT(kLastFlag < kBitsPerInt);
@@ skipping 1202 matching lines @@
     return Representation::Tagged();
   }
 
   DECLARE_CONCRETE_INSTRUCTION(ExternalArrayLength)
 
  protected:
   virtual bool DataEquals(HValue* other) { return true; }
 };
 
 
+class HElementsKind: public HUnaryOperation {
+ public:
+  explicit HElementsKind(HValue* value) : HUnaryOperation(value) {
+    set_representation(Representation::Integer32());
+    SetFlag(kUseGVN);
+    SetFlag(kDependsOnMaps);
+  }
+
+  virtual Representation RequiredInputRepresentation(int index) const {
+    return Representation::Tagged();
+  }
+
+  DECLARE_CONCRETE_INSTRUCTION(ElementsKind)
+
+ protected:
+  virtual bool DataEquals(HValue* other) { return true; }
+};
+
+
 class HBitNot: public HUnaryOperation {
  public:
   explicit HBitNot(HValue* value) : HUnaryOperation(value) {
     set_representation(Representation::Integer32());
     SetFlag(kUseGVN);
     SetFlag(kTruncatingToInt32);
   }
 
   virtual Representation RequiredInputRepresentation(int index) const {
     return Representation::Integer32();
@@ skipping 862 matching lines @@
  protected:
   virtual bool DataEquals(HValue* other) {
     return op_ == HCompareSymbolEq::cast(other)->op_;
   }
 
  private:
   const Token::Value op_;
 };
 
 
+class HCompareWithConstant: public HUnaryOperation {
+ public:
+  HCompareWithConstant(HValue* left, int right, Token::Value op)
+      : HUnaryOperation(left), op_(op), right_(right) {
+    ASSERT(op == Token::EQ || op == Token::EQ_STRICT);
+    set_representation(Representation::Tagged());
+    SetFlag(kUseGVN);
+  }
+
+  Token::Value op() const { return op_; }
+  int right() const { return right_; }
+
+  virtual bool EmitAtUses() {
+    return !HasSideEffects() && !HasMultipleUses();
+  }
+
+  virtual Representation RequiredInputRepresentation(int index) const {
+    return Representation::Integer32();
+  }
+
+  virtual HType CalculateInferredType() { return HType::Boolean(); }
+
+  DECLARE_CONCRETE_INSTRUCTION(CompareWithConstant);
+
+ protected:
+  virtual bool DataEquals(HValue* other) {
+    HCompareWithConstant* other_instr = HCompareWithConstant::cast(other);
+    return (op_ == other_instr->op_ &&
+        right_ == other_instr->right_);
+  }
+
+ private:
+  const Token::Value op_;
+  const int right_;
+};
+
+
 class HUnaryPredicate: public HUnaryOperation {
  public:
   explicit HUnaryPredicate(HValue* value) : HUnaryOperation(value) {
     set_representation(Representation::Tagged());
     SetFlag(kUseGVN);
   }
 
   virtual bool EmitAtUses() {
     return !HasSideEffects() && !HasMultipleUses();
   }
@@ skipping 85 matching lines @@
   HHasInstanceType(HValue* value, InstanceType type)
       : HUnaryPredicate(value), from_(type), to_(type) { }
   HHasInstanceType(HValue* value, InstanceType from, InstanceType to)
       : HUnaryPredicate(value), from_(from), to_(to) {
     ASSERT(to == LAST_TYPE);  // Others not implemented yet in backend.
   }
 
   InstanceType from() { return from_; }
   InstanceType to() { return to_; }
 
+  virtual bool EmitAtUses() {
+    return !HasSideEffects() && !HasMultipleUses();
+  }
+
   virtual void PrintDataTo(StringStream* stream);
 
   DECLARE_CONCRETE_INSTRUCTION(HasInstanceType)
 
  protected:
   virtual bool DataEquals(HValue* other) {
     HHasInstanceType* b = HHasInstanceType::cast(other);
     return (from_ == b->from()) && (to_ == b->to());
   }
 
@@ skipping 1329 matching lines @@
 
   DECLARE_CONCRETE_INSTRUCTION(In)
 };
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_