src/v8/src/ia32/code-stubs-ia32.h - cobalt - Git at Google

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 #ifndef V8_IA32_CODE_STUBS_IA32_H_
 #define V8_IA32_CODE_STUBS_IA32_H_

 namespace v8 {
 namespace internal {


 class StringHelper : public AllStatic {
  public:
   // Compares two flat one byte strings and returns result in eax.
   static void GenerateCompareFlatOneByteStrings(MacroAssembler* masm,
                                                 Register left, Register right,
                                                 Register scratch1,
                                                 Register scratch2,
                                                 Register scratch3);

   // Compares two flat one byte strings for equality and returns result in eax.
   static void GenerateFlatOneByteStringEquals(MacroAssembler* masm,
                                               Register left, Register right,
                                               Register scratch1,
                                               Register scratch2);

  private:
   static void GenerateOneByteCharsCompareLoop(
       MacroAssembler* masm, Register left, Register right, Register length,
       Register scratch, Label* chars_not_equal,
       Label::Distance chars_not_equal_near = Label::kFar);

   DISALLOW_IMPLICIT_CONSTRUCTORS(StringHelper);
 };


 class NameDictionaryLookupStub: public PlatformCodeStub {
  public:
   enum LookupMode { POSITIVE_LOOKUP, NEGATIVE_LOOKUP };

   NameDictionaryLookupStub(Isolate* isolate, Register dictionary,
                            Register result, Register index, LookupMode mode)
       : PlatformCodeStub(isolate) {
     minor_key_ = DictionaryBits::encode(dictionary.code()) |
                  ResultBits::encode(result.code()) |
                  IndexBits::encode(index.code()) | LookupModeBits::encode(mode);
   }

   static void GenerateNegativeLookup(MacroAssembler* masm,
                                      Label* miss,
                                      Label* done,
                                      Register properties,
                                      Handle<Name> name,
                                      Register r0);

   bool SometimesSetsUpAFrame() override { return false; }

  private:
   static const int kInlinedProbes = 4;
   static const int kTotalProbes = 20;

   static const int kCapacityOffset =
       NameDictionary::kHeaderSize +
       NameDictionary::kCapacityIndex * kPointerSize;

   static const int kElementsStartOffset =
       NameDictionary::kHeaderSize +
       NameDictionary::kElementsStartIndex * kPointerSize;

   Register dictionary() const {
     return Register::from_code(DictionaryBits::decode(minor_key_));
   }

   Register result() const {
     return Register::from_code(ResultBits::decode(minor_key_));
   }

   Register index() const {
     return Register::from_code(IndexBits::decode(minor_key_));
   }

   LookupMode mode() const { return LookupModeBits::decode(minor_key_); }

   class DictionaryBits: public BitField<int, 0, 3> {};
   class ResultBits: public BitField<int, 3, 3> {};
   class IndexBits: public BitField<int, 6, 3> {};
   class LookupModeBits: public BitField<LookupMode, 9, 1> {};

   DEFINE_NULL_CALL_INTERFACE_DESCRIPTOR();
   DEFINE_PLATFORM_CODE_STUB(NameDictionaryLookup, PlatformCodeStub);
 };


 class RecordWriteStub: public PlatformCodeStub {
  public:
   RecordWriteStub(Isolate* isolate,
                   Register object,
                   Register value,
                   Register address,
                   RememberedSetAction remembered_set_action,
                   SaveFPRegsMode fp_mode)
       : PlatformCodeStub(isolate),
         regs_(object,   // An input reg.
               address,  // An input reg.
               value) {  // One scratch reg.
     minor_key_ = ObjectBits::encode(object.code()) |
                  ValueBits::encode(value.code()) |
                  AddressBits::encode(address.code()) |
                  RememberedSetActionBits::encode(remembered_set_action) |
                  SaveFPRegsModeBits::encode(fp_mode);
   }

   RecordWriteStub(uint32_t key, Isolate* isolate)
       : PlatformCodeStub(key, isolate), regs_(object(), address(), value()) {}

   enum Mode {
     STORE_BUFFER_ONLY,
     INCREMENTAL,
     INCREMENTAL_COMPACTION
   };

   bool SometimesSetsUpAFrame() override { return false; }

   static const byte kTwoByteNopInstruction = 0x3c;  // Cmpb al, #imm8.
   static const byte kTwoByteJumpInstruction = 0xeb;  // Jmp #imm8.

   static const byte kFiveByteNopInstruction = 0x3d;  // Cmpl eax, #imm32.
   static const byte kFiveByteJumpInstruction = 0xe9;  // Jmp #imm32.

   static Mode GetMode(Code* stub);

   static void Patch(Code* stub, Mode mode);

   DEFINE_NULL_CALL_INTERFACE_DESCRIPTOR();

  private:
   // This is a helper class for freeing up 3 scratch registers, where the third
   // is always ecx (needed for shift operations).  The input is two registers
   // that must be preserved and one scratch register provided by the caller.
   class RegisterAllocation {
    public:
     RegisterAllocation(Register object, Register address, Register scratch0)
         : object_orig_(object),
           address_orig_(address),
           scratch0_orig_(scratch0),
           object_(object),
           address_(address),
           scratch0_(scratch0),
           scratch1_(no_reg) {
       DCHECK(!AreAliased(scratch0, object, address, no_reg));
       scratch1_ = GetRegThatIsNotEcxOr(object_, address_, scratch0_);
       if (scratch0 == ecx) {
         scratch0_ = GetRegThatIsNotEcxOr(object_, address_, scratch1_);
       }
       if (object == ecx) {
         object_ = GetRegThatIsNotEcxOr(address_, scratch0_, scratch1_);
       }
       if (address == ecx) {
         address_ = GetRegThatIsNotEcxOr(object_, scratch0_, scratch1_);
       }
       DCHECK(!AreAliased(scratch0_, object_, address_, ecx));
     }

     void Save(MacroAssembler* masm) {
       DCHECK(address_orig_ != object_);
       DCHECK(object_ == object_orig_ || address_ == address_orig_);
       DCHECK(!AreAliased(object_, address_, scratch1_, scratch0_));
       DCHECK(!AreAliased(object_orig_, address_, scratch1_, scratch0_));
       DCHECK(!AreAliased(object_, address_orig_, scratch1_, scratch0_));
       // We don't have to save scratch0_orig_ because it was given to us as
       // a scratch register.  But if we had to switch to a different reg then
       // we should save the new scratch0_.
       if (scratch0_ != scratch0_orig_) masm->push(scratch0_);
       if (ecx != scratch0_orig_ && ecx != object_orig_ &&
           ecx != address_orig_) {
         masm->push(ecx);
       }
       masm->push(scratch1_);
       if (address_ != address_orig_) {
         masm->push(address_);
         masm->mov(address_, address_orig_);
       }
       if (object_ != object_orig_) {
         masm->push(object_);
         masm->mov(object_, object_orig_);
       }
     }

     void Restore(MacroAssembler* masm) {
       // These will have been preserved the entire time, so we just need to move
       // them back.  Only in one case is the orig_ reg different from the plain
       // one, since only one of them can alias with ecx.
       if (object_ != object_orig_) {
         masm->mov(object_orig_, object_);
         masm->pop(object_);
       }
       if (address_ != address_orig_) {
         masm->mov(address_orig_, address_);
         masm->pop(address_);
       }
       masm->pop(scratch1_);
       if (ecx != scratch0_orig_ && ecx != object_orig_ &&
           ecx != address_orig_) {
         masm->pop(ecx);
       }
       if (scratch0_ != scratch0_orig_) masm->pop(scratch0_);
     }

     // If we have to call into C then we need to save and restore all caller-
     // saved registers that were not already preserved.  The caller saved
     // registers are eax, ecx and edx.  The three scratch registers (incl. ecx)
     // will be restored by other means so we don't bother pushing them here.
     void SaveCallerSaveRegisters(MacroAssembler* masm, SaveFPRegsMode mode) {
       masm->PushCallerSaved(mode, ecx, scratch0_, scratch1_);
     }

     inline void RestoreCallerSaveRegisters(MacroAssembler* masm,
                                            SaveFPRegsMode mode) {
       masm->PopCallerSaved(mode, ecx, scratch0_, scratch1_);
     }

     inline Register object() { return object_; }
     inline Register address() { return address_; }
     inline Register scratch0() { return scratch0_; }
     inline Register scratch1() { return scratch1_; }

    private:
     Register object_orig_;
     Register address_orig_;
     Register scratch0_orig_;
     Register object_;
     Register address_;
     Register scratch0_;
     Register scratch1_;
     // Third scratch register is always ecx.

     Register GetRegThatIsNotEcxOr(Register r1,
                                   Register r2,
                                   Register r3) {
       for (int i = 0; i < Register::kNumRegisters; i++) {
         if (RegisterConfiguration::Default()->IsAllocatableGeneralCode(i)) {
           Register candidate = Register::from_code(i);
           if (candidate != ecx && candidate != r1 && candidate != r2 &&
               candidate != r3) {
             return candidate;
           }
         }
       }
       UNREACHABLE();
     }
     friend class RecordWriteStub;
   };

   enum OnNoNeedToInformIncrementalMarker {
     kReturnOnNoNeedToInformIncrementalMarker,
     kUpdateRememberedSetOnNoNeedToInformIncrementalMarker
   };

   inline Major MajorKey() const final { return RecordWrite; }

   void Generate(MacroAssembler* masm) override;
   void GenerateIncremental(MacroAssembler* masm, Mode mode);
   void CheckNeedsToInformIncrementalMarker(
       MacroAssembler* masm,
       OnNoNeedToInformIncrementalMarker on_no_need,
       Mode mode);
   void InformIncrementalMarker(MacroAssembler* masm);

   void Activate(Code* code) override;

   Register object() const {
     return Register::from_code(ObjectBits::decode(minor_key_));
   }

   Register value() const {
     return Register::from_code(ValueBits::decode(minor_key_));
   }

   Register address() const {
     return Register::from_code(AddressBits::decode(minor_key_));
   }

   RememberedSetAction remembered_set_action() const {
     return RememberedSetActionBits::decode(minor_key_);
   }

   SaveFPRegsMode save_fp_regs_mode() const {
     return SaveFPRegsModeBits::decode(minor_key_);
   }

   class ObjectBits: public BitField<int, 0, 3> {};
   class ValueBits: public BitField<int, 3, 3> {};
   class AddressBits: public BitField<int, 6, 3> {};
   class RememberedSetActionBits: public BitField<RememberedSetAction, 9, 1> {};
   class SaveFPRegsModeBits: public BitField<SaveFPRegsMode, 10, 1> {};

   RegisterAllocation regs_;

   DISALLOW_COPY_AND_ASSIGN(RecordWriteStub);
 };


 }  // namespace internal
 }  // namespace v8

 #endif  // V8_IA32_CODE_STUBS_IA32_H_
	// Copyright 2011 the V8 project authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	#ifndef V8_IA32_CODE_STUBS_IA32_H_
	#define V8_IA32_CODE_STUBS_IA32_H_

	namespace v8 {
	namespace internal {


	class StringHelper : public AllStatic {
	public:
	// Compares two flat one byte strings and returns result in eax.
	static void GenerateCompareFlatOneByteStrings(MacroAssembler* masm,
	Register left, Register right,
	Register scratch1,
	Register scratch2,
	Register scratch3);

	// Compares two flat one byte strings for equality and returns result in eax.
	static void GenerateFlatOneByteStringEquals(MacroAssembler* masm,
	Register left, Register right,
	Register scratch1,
	Register scratch2);

	private:
	static void GenerateOneByteCharsCompareLoop(
	MacroAssembler* masm, Register left, Register right, Register length,
	Register scratch, Label* chars_not_equal,
	Label::Distance chars_not_equal_near = Label::kFar);

	DISALLOW_IMPLICIT_CONSTRUCTORS(StringHelper);
	};


	class NameDictionaryLookupStub: public PlatformCodeStub {
	public:
	enum LookupMode { POSITIVE_LOOKUP, NEGATIVE_LOOKUP };

	NameDictionaryLookupStub(Isolate* isolate, Register dictionary,
	Register result, Register index, LookupMode mode)
	: PlatformCodeStub(isolate) {
	minor_key_ = DictionaryBits::encode(dictionary.code()) \|
	ResultBits::encode(result.code()) \|
	IndexBits::encode(index.code()) \| LookupModeBits::encode(mode);
	}

	static void GenerateNegativeLookup(MacroAssembler* masm,
	Label* miss,
	Label* done,
	Register properties,
	Handle<Name> name,
	Register r0);

	bool SometimesSetsUpAFrame() override { return false; }

	private:
	static const int kInlinedProbes = 4;
	static const int kTotalProbes = 20;

	static const int kCapacityOffset =
	NameDictionary::kHeaderSize +
	NameDictionary::kCapacityIndex * kPointerSize;

	static const int kElementsStartOffset =
	NameDictionary::kHeaderSize +
	NameDictionary::kElementsStartIndex * kPointerSize;

	Register dictionary() const {
	return Register::from_code(DictionaryBits::decode(minor_key_));
	}

	Register result() const {
	return Register::from_code(ResultBits::decode(minor_key_));
	}

	Register index() const {
	return Register::from_code(IndexBits::decode(minor_key_));
	}

	LookupMode mode() const { return LookupModeBits::decode(minor_key_); }

	class DictionaryBits: public BitField<int, 0, 3> {};
	class ResultBits: public BitField<int, 3, 3> {};
	class IndexBits: public BitField<int, 6, 3> {};
	class LookupModeBits: public BitField<LookupMode, 9, 1> {};

	DEFINE_NULL_CALL_INTERFACE_DESCRIPTOR();
	DEFINE_PLATFORM_CODE_STUB(NameDictionaryLookup, PlatformCodeStub);
	};


	class RecordWriteStub: public PlatformCodeStub {
	public:
	RecordWriteStub(Isolate* isolate,
	Register object,
	Register value,
	Register address,
	RememberedSetAction remembered_set_action,
	SaveFPRegsMode fp_mode)
	: PlatformCodeStub(isolate),
	regs_(object, // An input reg.
	address, // An input reg.
	value) { // One scratch reg.
	minor_key_ = ObjectBits::encode(object.code()) \|
	ValueBits::encode(value.code()) \|
	AddressBits::encode(address.code()) \|
	RememberedSetActionBits::encode(remembered_set_action) \|
	SaveFPRegsModeBits::encode(fp_mode);
	}

	RecordWriteStub(uint32_t key, Isolate* isolate)
	: PlatformCodeStub(key, isolate), regs_(object(), address(), value()) {}

	enum Mode {
	STORE_BUFFER_ONLY,
	INCREMENTAL,
	INCREMENTAL_COMPACTION
	};

	bool SometimesSetsUpAFrame() override { return false; }

	static const byte kTwoByteNopInstruction = 0x3c; // Cmpb al, #imm8.
	static const byte kTwoByteJumpInstruction = 0xeb; // Jmp #imm8.

	static const byte kFiveByteNopInstruction = 0x3d; // Cmpl eax, #imm32.
	static const byte kFiveByteJumpInstruction = 0xe9; // Jmp #imm32.

	static Mode GetMode(Code* stub);

	static void Patch(Code* stub, Mode mode);

	DEFINE_NULL_CALL_INTERFACE_DESCRIPTOR();

	private:
	// This is a helper class for freeing up 3 scratch registers, where the third
	// is always ecx (needed for shift operations). The input is two registers
	// that must be preserved and one scratch register provided by the caller.
	class RegisterAllocation {
	public:
	RegisterAllocation(Register object, Register address, Register scratch0)
	: object_orig_(object),
	address_orig_(address),
	scratch0_orig_(scratch0),
	object_(object),
	address_(address),
	scratch0_(scratch0),
	scratch1_(no_reg) {
	DCHECK(!AreAliased(scratch0, object, address, no_reg));
	scratch1_ = GetRegThatIsNotEcxOr(object_, address_, scratch0_);
	if (scratch0 == ecx) {
	scratch0_ = GetRegThatIsNotEcxOr(object_, address_, scratch1_);
	}
	if (object == ecx) {
	object_ = GetRegThatIsNotEcxOr(address_, scratch0_, scratch1_);
	}
	if (address == ecx) {
	address_ = GetRegThatIsNotEcxOr(object_, scratch0_, scratch1_);
	}
	DCHECK(!AreAliased(scratch0_, object_, address_, ecx));
	}

	void Save(MacroAssembler* masm) {
	DCHECK(address_orig_ != object_);
	DCHECK(object_ == object_orig_ \|\| address_ == address_orig_);
	DCHECK(!AreAliased(object_, address_, scratch1_, scratch0_));
	DCHECK(!AreAliased(object_orig_, address_, scratch1_, scratch0_));
	DCHECK(!AreAliased(object_, address_orig_, scratch1_, scratch0_));
	// We don't have to save scratch0_orig_ because it was given to us as
	// a scratch register. But if we had to switch to a different reg then
	// we should save the new scratch0_.
	if (scratch0_ != scratch0_orig_) masm->push(scratch0_);
	if (ecx != scratch0_orig_ && ecx != object_orig_ &&
	ecx != address_orig_) {
	masm->push(ecx);
	}
	masm->push(scratch1_);
	if (address_ != address_orig_) {
	masm->push(address_);
	masm->mov(address_, address_orig_);
	}
	if (object_ != object_orig_) {
	masm->push(object_);
	masm->mov(object_, object_orig_);
	}
	}

	void Restore(MacroAssembler* masm) {
	// These will have been preserved the entire time, so we just need to move
	// them back. Only in one case is the orig_ reg different from the plain
	// one, since only one of them can alias with ecx.
	if (object_ != object_orig_) {
	masm->mov(object_orig_, object_);
	masm->pop(object_);
	}
	if (address_ != address_orig_) {
	masm->mov(address_orig_, address_);
	masm->pop(address_);
	}
	masm->pop(scratch1_);
	if (ecx != scratch0_orig_ && ecx != object_orig_ &&
	ecx != address_orig_) {
	masm->pop(ecx);
	}
	if (scratch0_ != scratch0_orig_) masm->pop(scratch0_);
	}

	// If we have to call into C then we need to save and restore all caller-
	// saved registers that were not already preserved. The caller saved
	// registers are eax, ecx and edx. The three scratch registers (incl. ecx)
	// will be restored by other means so we don't bother pushing them here.
	void SaveCallerSaveRegisters(MacroAssembler* masm, SaveFPRegsMode mode) {
	masm->PushCallerSaved(mode, ecx, scratch0_, scratch1_);
	}

	inline void RestoreCallerSaveRegisters(MacroAssembler* masm,
	SaveFPRegsMode mode) {
	masm->PopCallerSaved(mode, ecx, scratch0_, scratch1_);
	}

	inline Register object() { return object_; }
	inline Register address() { return address_; }
	inline Register scratch0() { return scratch0_; }
	inline Register scratch1() { return scratch1_; }

	private:
	Register object_orig_;
	Register address_orig_;
	Register scratch0_orig_;
	Register object_;
	Register address_;
	Register scratch0_;
	Register scratch1_;
	// Third scratch register is always ecx.

	Register GetRegThatIsNotEcxOr(Register r1,
	Register r2,
	Register r3) {
	for (int i = 0; i < Register::kNumRegisters; i++) {
	if (RegisterConfiguration::Default()->IsAllocatableGeneralCode(i)) {
	Register candidate = Register::from_code(i);
	if (candidate != ecx && candidate != r1 && candidate != r2 &&
	candidate != r3) {
	return candidate;
	}
	}
	}
	UNREACHABLE();
	}
	friend class RecordWriteStub;
	};

	enum OnNoNeedToInformIncrementalMarker {
	kReturnOnNoNeedToInformIncrementalMarker,
	kUpdateRememberedSetOnNoNeedToInformIncrementalMarker
	};

	inline Major MajorKey() const final { return RecordWrite; }

	void Generate(MacroAssembler* masm) override;
	void GenerateIncremental(MacroAssembler* masm, Mode mode);
	void CheckNeedsToInformIncrementalMarker(
	MacroAssembler* masm,
	OnNoNeedToInformIncrementalMarker on_no_need,
	Mode mode);
	void InformIncrementalMarker(MacroAssembler* masm);

	void Activate(Code* code) override;

	Register object() const {
	return Register::from_code(ObjectBits::decode(minor_key_));
	}

	Register value() const {
	return Register::from_code(ValueBits::decode(minor_key_));
	}

	Register address() const {
	return Register::from_code(AddressBits::decode(minor_key_));
	}

	RememberedSetAction remembered_set_action() const {
	return RememberedSetActionBits::decode(minor_key_);
	}

	SaveFPRegsMode save_fp_regs_mode() const {
	return SaveFPRegsModeBits::decode(minor_key_);
	}

	class ObjectBits: public BitField<int, 0, 3> {};
	class ValueBits: public BitField<int, 3, 3> {};
	class AddressBits: public BitField<int, 6, 3> {};
	class RememberedSetActionBits: public BitField<RememberedSetAction, 9, 1> {};
	class SaveFPRegsModeBits: public BitField<SaveFPRegsMode, 10, 1> {};

	RegisterAllocation regs_;

	DISALLOW_COPY_AND_ASSIGN(RecordWriteStub);
	};


	} // namespace internal
	} // namespace v8

	#endif // V8_IA32_CODE_STUBS_IA32_H_