Lattice-based representation inference, powered by left/right specific type feedback for BinaryOps …

src/code-stubs.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 464 matching lines @@
   virtual void Generate(MacroAssembler* masm);
 
  private:
   virtual CodeStub::Major MajorKey() { return MathPow; }
   virtual int MinorKey() { return exponent_type_; }
 
   ExponentType exponent_type_;
 };
 
 
+class BinaryOpStub: public CodeStub {
+ public:
+  BinaryOpStub(Token::Value op, OverwriteMode mode)
+      : op_(op),
+        mode_(mode),
+        platform_specific_bit_(false),
+        left_type_(BinaryOpIC::UNINITIALIZED),
+        right_type_(BinaryOpIC::UNINITIALIZED),
+        result_type_(BinaryOpIC::UNINITIALIZED) {
+    Initialize();
+    ASSERT(OpBits::is_valid(Token::NUM_TOKENS));
+  }
+
+  BinaryOpStub(
+      int key,
+      BinaryOpIC::TypeInfo left_type,
+      BinaryOpIC::TypeInfo right_type,
+      BinaryOpIC::TypeInfo result_type = BinaryOpIC::UNINITIALIZED)
+      : op_(OpBits::decode(key)),
+        mode_(ModeBits::decode(key)),
+        platform_specific_bit_(PlatformSpecificBits::decode(key)),
+        left_type_(left_type),
+        right_type_(right_type),
+        result_type_(result_type) { }
+
+  static void decode_types_from_minor_key(int minor_key,
+                                          BinaryOpIC::TypeInfo* left_type,
+                                          BinaryOpIC::TypeInfo* right_type,
+                                          BinaryOpIC::TypeInfo* result_type) {
+    *left_type =
+        static_cast<BinaryOpIC::TypeInfo>(LeftTypeBits::decode(minor_key));
+    *right_type =
+        static_cast<BinaryOpIC::TypeInfo>(RightTypeBits::decode(minor_key));
+    *result_type =
+        static_cast<BinaryOpIC::TypeInfo>(ResultTypeBits::decode(minor_key));
+  }
+
+  static Token::Value decode_op_from_minor_key(int minor_key) {
+    return static_cast<Token::Value>(OpBits::decode(minor_key));
+  }
+
+  enum SmiCodeGenerateHeapNumberResults {
+    ALLOW_HEAPNUMBER_RESULTS,
+    NO_HEAPNUMBER_RESULTS
+  };
+
+ private:
+  Token::Value op_;
+  OverwriteMode mode_;
+  bool platform_specific_bit_;  // Indicates SSE3 on IA32, VFP2 on ARM.
+
+  // Operand type information determined at runtime.
+  BinaryOpIC::TypeInfo left_type_;
+  BinaryOpIC::TypeInfo right_type_;
+  BinaryOpIC::TypeInfo result_type_;
+
+  virtual void PrintName(StringStream* stream);
+
+  // Minor key encoding in 19 bits TTTRRRLLLSOOOOOOOMM.
+  class ModeBits: public BitField<OverwriteMode, 0, 2> {};
+  class OpBits: public BitField<Token::Value, 2, 7> {};
+  class PlatformSpecificBits: public BitField<bool, 9, 1> {};
+  class LeftTypeBits: public BitField<BinaryOpIC::TypeInfo, 10, 3> {};
+  class RightTypeBits: public BitField<BinaryOpIC::TypeInfo, 13, 3> {};
+  class ResultTypeBits: public BitField<BinaryOpIC::TypeInfo, 16, 3> {};
+
+  Major MajorKey() { return BinaryOp; }
+  int MinorKey() {
+    return OpBits::encode(op_)
+           | ModeBits::encode(mode_)
+           | PlatformSpecificBits::encode(platform_specific_bit_)
+           | LeftTypeBits::encode(left_type_)
+           | RightTypeBits::encode(right_type_)
+           | ResultTypeBits::encode(result_type_);
+  }
+
+
+  // Platform-independent implementation.
+  void Generate(MacroAssembler* masm);
+  void GenerateCallRuntime(MacroAssembler* masm);
+
+  // Platform-independent signature, platform-specific implementation.
+  void Initialize();
+  void GenerateAddStrings(MacroAssembler* masm);
+  void GenerateBothStringStub(MacroAssembler* masm);
+  void GenerateGeneric(MacroAssembler* masm);
+  void GenerateGenericStub(MacroAssembler* masm);
+  void GenerateHeapNumberStub(MacroAssembler* masm);
+  void GenerateInt32Stub(MacroAssembler* masm);
+  void GenerateLoadArguments(MacroAssembler* masm);
+  void GenerateOddballStub(MacroAssembler* masm);
+  void GenerateRegisterArgsPush(MacroAssembler* masm);
+  void GenerateReturn(MacroAssembler* masm);
+  void GenerateSmiStub(MacroAssembler* masm);
+  void GenerateStringStub(MacroAssembler* masm);
+  void GenerateTypeTransition(MacroAssembler* masm);
+  void GenerateTypeTransitionWithSavedArgs(MacroAssembler* masm);
+  void GenerateUninitializedStub(MacroAssembler* masm);
+
+  // Entirely platform-specific methods are defined as static helper
+  // functions in the <arch>/code-stubs-<arch>.cc files.
+
+  virtual int GetCodeKind() { return Code::BINARY_OP_IC; }
+
+  virtual InlineCacheState GetICState() {
+    return BinaryOpIC::ToState(Max(left_type_, right_type_));
+  }
+
+  virtual void FinishCode(Handle<Code> code) {
+    code->set_stub_info(MinorKey());
+  }
+
+  friend class CodeGenerator;
+};
+
+
 class ICCompareStub: public CodeStub {
  public:
-  ICCompareStub(Token::Value op, CompareIC::State state)
-      : op_(op), state_(state) {
+  ICCompareStub(Token::Value op,
+                CompareIC::State left,
+                CompareIC::State right,
+                CompareIC::State handler)
+      : op_(op),
+        left_(left),
+        right_(right),
+        state_(handler) {
     ASSERT(Token::IsCompareOp(op));
   }
 
   virtual void Generate(MacroAssembler* masm);
 
   void set_known_map(Handle<Map> map) { known_map_ = map; }
 
+  static void DecodeMinorKey(int minor_key,
+                             CompareIC::State* left_state,
+                             CompareIC::State* right_state,
+                             CompareIC::State* handler_state,
+                             Token::Value* op);
+
+  static CompareIC::State CompareState(int minor_key) {
+    return static_cast<CompareIC::State>(HandlerStateField::decode(minor_key));
+  }
+
  private:
   class OpField: public BitField<int, 0, 3> { };
-  class StateField: public BitField<int, 3, 5> { };
+  class LeftStateField: public BitField<int, 3, 3> { };
+  class RightStateField: public BitField<int, 6, 3> { };
+  class HandlerStateField: public BitField<int, 9, 3> { };
 
   virtual void FinishCode(Handle<Code> code) {
-    code->set_compare_state(state_);
-    code->set_compare_operation(op_ - Token::EQ);
+    code->set_stub_info(MinorKey());
   }
 
   virtual CodeStub::Major MajorKey() { return CompareIC; }
   virtual int MinorKey();
 
   virtual int GetCodeKind() { return Code::COMPARE_IC; }
 
   void GenerateSmis(MacroAssembler* masm);
   void GenerateHeapNumbers(MacroAssembler* masm);
   void GenerateSymbols(MacroAssembler* masm);
   void GenerateStrings(MacroAssembler* masm);
   void GenerateObjects(MacroAssembler* masm);
   void GenerateMiss(MacroAssembler* masm);
   void GenerateKnownObjects(MacroAssembler* masm);
+  void GenerateGeneric(MacroAssembler* masm);
 
   bool strict() const { return op_ == Token::EQ_STRICT; }
   Condition GetCondition() const { return CompareIC::ComputeCondition(op_); }
 
   virtual void AddToSpecialCache(Handle<Code> new_object);
   virtual bool FindCodeInSpecialCache(Code** code_out);
   virtual bool UseSpecialCache() { return state_ == CompareIC::KNOWN_OBJECTS; }
 
   Token::Value op_;
+  CompareIC::State left_;
+  CompareIC::State right_;
   CompareIC::State state_;
   Handle<Map> known_map_;
 };
 
 
-// Flags that control the compare stub code generation.
-enum CompareFlags {
-  NO_COMPARE_FLAGS = 0,
-  NO_SMI_COMPARE_IN_STUB = 1 << 0,
-  NO_NUMBER_COMPARE_IN_STUB = 1 << 1,
-  CANT_BOTH_BE_NAN = 1 << 2
-};
-
-
-enum NaNInformation {
-  kBothCouldBeNaN,
-  kCantBothBeNaN
-};
-
-
-class CompareStub: public CodeStub {
- public:
-  CompareStub(Condition cc,
-              bool strict,
-              CompareFlags flags,
-              Register lhs,
-              Register rhs) :
-     cc_(cc),
-      strict_(strict),
-      never_nan_nan_((flags & CANT_BOTH_BE_NAN) != 0),
-      include_number_compare_((flags & NO_NUMBER_COMPARE_IN_STUB) == 0),
-      include_smi_compare_((flags & NO_SMI_COMPARE_IN_STUB) == 0),
-      lhs_(lhs),
-      rhs_(rhs) { }
-
-  CompareStub(Condition cc,
-              bool strict,
-              CompareFlags flags) :
-      cc_(cc),
-      strict_(strict),
-      never_nan_nan_((flags & CANT_BOTH_BE_NAN) != 0),
-      include_number_compare_((flags & NO_NUMBER_COMPARE_IN_STUB) == 0),
-      include_smi_compare_((flags & NO_SMI_COMPARE_IN_STUB) == 0),
-      lhs_(no_reg),
-      rhs_(no_reg) { }
-
-  void Generate(MacroAssembler* masm);
-
- private:
-  Condition cc_;
-  bool strict_;
-  // Only used for 'equal' comparisons.  Tells the stub that we already know
-  // that at least one side of the comparison is not NaN.  This allows the
-  // stub to use object identity in the positive case.  We ignore it when
-  // generating the minor key for other comparisons to avoid creating more
-  // stubs.
-  bool never_nan_nan_;
-  // Do generate the number comparison code in the stub. Stubs without number
-  // comparison code is used when the number comparison has been inlined, and
-  // the stub will be called if one of the operands is not a number.
-  bool include_number_compare_;
-
-  // Generate the comparison code for two smi operands in the stub.
-  bool include_smi_compare_;
-
-  // Register holding the left hand side of the comparison if the stub gives
-  // a choice, no_reg otherwise.
-
-  Register lhs_;
-  // Register holding the right hand side of the comparison if the stub gives
-  // a choice, no_reg otherwise.
-  Register rhs_;
-
-  // Encoding of the minor key in 16 bits.
-  class StrictField: public BitField<bool, 0, 1> {};
-  class NeverNanNanField: public BitField<bool, 1, 1> {};
-  class IncludeNumberCompareField: public BitField<bool, 2, 1> {};
-  class IncludeSmiCompareField: public  BitField<bool, 3, 1> {};
-  class RegisterField: public BitField<bool, 4, 1> {};
-  class ConditionField: public BitField<int, 5, 11> {};
-
-  Major MajorKey() { return Compare; }
-
-  int MinorKey();
-
-  virtual int GetCodeKind() { return Code::COMPARE_IC; }
-  virtual void FinishCode(Handle<Code> code) {
-    code->set_compare_state(CompareIC::GENERIC);
-  }
-
-  // Branch to the label if the given object isn't a symbol.
-  void BranchIfNonSymbol(MacroAssembler* masm,
-                         Label* label,
-                         Register object,
-                         Register scratch);
-
-  // Unfortunately you have to run without snapshots to see most of these
-  // names in the profile since most compare stubs end up in the snapshot.
-  virtual void PrintName(StringStream* stream);
-};
-
-
 class CEntryStub : public CodeStub {
  public:
   explicit CEntryStub(int result_size,
                       SaveFPRegsMode save_doubles = kDontSaveFPRegs)
       : result_size_(result_size), save_doubles_(save_doubles) { }
 
   void Generate(MacroAssembler* masm);
 
   // The version of this stub that doesn't save doubles is generated ahead of
   // time, so it's OK to call it from other stubs that can't cope with GC during
@@ skipping 408 matching lines @@
   // only has room for a single byte to hold a set of these types. :-P
   STATIC_ASSERT(NUMBER_OF_TYPES <= 8);
 
   class Types {
    public:
     Types() {}
     explicit Types(byte bits) : set_(bits) {}
 
     bool IsEmpty() const { return set_.IsEmpty(); }
     bool Contains(Type type) const { return set_.Contains(type); }
+    bool ContainsAnyOf(Types types) const {
+      return set_.ContainsAnyOf(types.set_);
+    }
     void Add(Type type) { set_.Add(type); }
     byte ToByte() const { return set_.ToIntegral(); }
     void Print(StringStream* stream) const;
     void TraceTransition(Types to) const;
     bool Record(Handle<Object> object);
     bool NeedsMap() const;
     bool CanBeUndetectable() const;
 
    private:
     EnumSet<Type, byte> set_;
@@ skipping 118 matching lines @@
 
   // The current function entry hook.
   static FunctionEntryHook entry_hook_;
 
   DISALLOW_COPY_AND_ASSIGN(ProfileEntryHookStub);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_CODE_STUBS_H_