src/arch/generic/pcstate.hh - public/gem5 - Git at Google

 /*
  * Copyright (c) 2020 ARM Limited
  * All rights reserved
  *
  * The license below extends only to copyright in the software and shall
  * not be construed as granting a license to any other intellectual
  * property including but not limited to intellectual property relating
  * to a hardware implementation of the functionality of the software
  * licensed hereunder.  You may use the software subject to the license
  * terms below provided that you ensure that this notice is replicated
  * unmodified and in its entirety in all distributions of the software,
  * modified or unmodified, in source code or in binary form.
  *
  * Copyright (c) 2010 Gabe Black
  * 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 with the distribution;
  * neither the name of the copyright holders nor the names of its
  * contributors may be used to endorse or promote products derived from
  * this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */

 #ifndef __ARCH_GENERIC_TYPES_HH__
 #define __ARCH_GENERIC_TYPES_HH__

 #include <iostream>
 #include <memory>
 #include <type_traits>

 #include "base/compiler.hh"
 #include "base/trace.hh"
 #include "base/types.hh"
 #include "sim/serialize.hh"

 namespace gem5
 {

 // The guaranteed interface.
 class PCStateBase : public Serializable
 {
   protected:
     Addr _pc = 0;
     MicroPC _upc = 0;

     PCStateBase(const PCStateBase &other) : _pc(other._pc), _upc(other._upc) {}
     PCStateBase &operator=(const PCStateBase &other) = default;
     PCStateBase() {}

   public:
     virtual ~PCStateBase() = default;

     template<class Target>
     Target &
     as()
     {
         return static_cast<Target &>(*this);
     }

     template<class Target>
     const Target &
     as() const
     {
         return static_cast<const Target &>(*this);
     }

     virtual PCStateBase *clone() const = 0;
     virtual void
     update(const PCStateBase &other)
     {
         _pc = other._pc;
         _upc = other._upc;
     }
     void update(const PCStateBase *ptr) { update(*ptr); }

     virtual void output(std::ostream &os) const = 0;

     virtual bool
     equals(const PCStateBase &other) const
     {
         return _pc == other._pc && _upc == other._upc;
     }

     /**
      * Returns the memory address of the instruction this PC points to.
      *
      * @return Memory address of the instruction this PC points to.
      */
     Addr
     instAddr() const
     {
         return _pc;
     }

     /**
      * Returns the current micropc.
      *
      * @return The current micropc.
      */
     MicroPC
     microPC() const
     {
         return _upc;
     }

     void
     serialize(CheckpointOut &cp) const override
     {
         SERIALIZE_SCALAR(_pc);
         SERIALIZE_SCALAR(_upc);
     }

     void
     unserialize(CheckpointIn &cp) override
     {
         UNSERIALIZE_SCALAR(_pc);
         UNSERIALIZE_SCALAR(_upc);
     }
 };

 static inline std::ostream &
 operator<<(std::ostream & os, const PCStateBase &pc)
 {
     pc.output(os);
     return os;
 }

 static inline bool
 operator==(const PCStateBase &a, const PCStateBase &b)
 {
     return a.equals(b);
 }

 static inline bool
 operator!=(const PCStateBase &a, const PCStateBase &b)
 {
     return !a.equals(b);
 }

 namespace
 {

 inline void
 set(PCStateBase *&dest, const PCStateBase *src)
 {
     if (GEM5_LIKELY(dest)) {
         if (GEM5_LIKELY(src)) {
             // Both src and dest already have storage, so just copy contents.
             dest->update(src);
         } else {
             // src is empty, so clear out dest.
             dest = nullptr;
         }
     } else {
         if (GEM5_LIKELY(src)) {
             // dest doesn't have storage, so create some as a copy of src.
             dest = src->clone();
         } else {
             // dest is already nullptr, so nothing to do.
         }
     }
 }

 inline void
 set(std::unique_ptr<PCStateBase> &dest, const PCStateBase *src)
 {
     PCStateBase *dest_ptr = dest.get();
     set(dest_ptr, src);
     if (dest.get() != dest_ptr)
         dest.reset(dest_ptr);
 }

 inline void
 set(PCStateBase *&dest, const std::unique_ptr<PCStateBase> &src)
 {
     const PCStateBase *src_ptr = src.get();
     set(dest, src_ptr);
 }

 inline void
 set(std::unique_ptr<PCStateBase> &dest,
         const std::unique_ptr<PCStateBase> &src)
 {
     PCStateBase *dest_ptr = dest.get();
     const PCStateBase *src_ptr = src.get();
     set(dest_ptr, src_ptr);
     if (dest.get() != dest_ptr)
         dest.reset(dest_ptr);
 }

 inline void
 set(PCStateBase *&dest, const PCStateBase &src)
 {
     if (GEM5_LIKELY(dest)) {
         // Update dest with the contents of src.
         dest->update(src);
     } else {
         // Clone src over to dest.
         dest = src.clone();
     }
 }

 inline void
 set(std::unique_ptr<PCStateBase> &dest, const PCStateBase &src)
 {
     PCStateBase *dest_ptr = dest.get();
     set(dest_ptr, src);
     if (dest.get() != dest_ptr)
         dest.reset(dest_ptr);
 }

 inline void
 set(PCStateBase &dest, const PCStateBase &src)
 {
     dest.update(src);
 }

 } // anonymous namespace

 namespace GenericISA
 {

 class PCStateCommon : public PCStateBase
 {
   protected:
     Addr _npc = 0;

     MicroPC _nupc = 1;

     PCStateCommon(const PCStateCommon &other) : PCStateBase(other),
         _npc(other._npc), _nupc(other._nupc)
     {}
     PCStateCommon &operator=(const PCStateCommon &other) = default;
     PCStateCommon() {}

   public:
     Addr pc() const { return _pc; }
     void pc(Addr val) { _pc = val; }

     Addr npc() const { return _npc; }
     void npc(Addr val) { _npc = val; }

     MicroPC upc() const { return _upc; }
     void upc(MicroPC val) { _upc = val; }

     MicroPC nupc() const { return _nupc; }
     void nupc(MicroPC val) { _nupc = val; }

     // Reset the macroop's upc without advancing the regular pc.
     void
     uReset()
     {
         _upc = 0;
         _nupc = 1;
     }

     void
     setNPC(Addr val)
     {
         npc(val);
     }

     void
     output(std::ostream &os) const override
     {
         ccprintf(os, "(%#x=>%#x)", this->pc(), this->npc());
     }

     void
     update(const PCStateBase &other) override
     {
         PCStateBase::update(other);
         auto &pcstate = other.as<PCStateCommon>();
         _npc = pcstate._npc;
         _nupc = pcstate._nupc;
     }

     bool
     equals(const PCStateBase &other) const override
     {
         auto &ps = other.as<PCStateCommon>();
         return PCStateBase::equals(other) &&
             _npc == ps._npc && _nupc == ps._nupc;
     }

     void
     serialize(CheckpointOut &cp) const override
     {
         PCStateBase::serialize(cp);
         SERIALIZE_SCALAR(_npc);
         SERIALIZE_SCALAR(_nupc);
     }

     void
     unserialize(CheckpointIn &cp) override
     {
         PCStateBase::unserialize(cp);
         UNSERIALIZE_SCALAR(_npc);
         UNSERIALIZE_SCALAR(_nupc);
     }
 };


 /*
  * Different flavors of PC state. Only ISA specific code should rely on
  * any particular type of PC state being available. All other code should
  * use the interface above.
  */

 // The most basic type of PC.
 template <int InstWidth>
 class SimplePCState : public PCStateCommon
 {
   protected:
     typedef PCStateCommon Base;

   public:
     SimplePCState(const SimplePCState &other) : Base(other) {}
     SimplePCState &operator=(const SimplePCState &other) = default;
     SimplePCState() {}
     explicit SimplePCState(Addr val) { set(val); }

     PCStateBase *
     clone() const override
     {
         return new SimplePCState<InstWidth>(*this);
     }

     /**
      * Force this PC to reflect a particular value, resetting all its other
      * fields around it. This is useful for in place (re)initialization.
      *
      * @param val The value to set the PC to.
      */
     void
     set(Addr val)
     {
         this->pc(val);
         this->npc(val + InstWidth);
     };

     bool
     branching() const
     {
         return this->npc() != this->pc() + InstWidth;
     }

     // Advance the PC.
     void
     advance()
     {
         this->_pc = this->_npc;
         this->_npc += InstWidth;
     }
 };

 // A PC and microcode PC.
 template <int InstWidth>
 class UPCState : public SimplePCState<InstWidth>
 {
   protected:
     typedef SimplePCState<InstWidth> Base;

   public:
     void
     output(std::ostream &os) const override
     {
         Base::output(os);
         ccprintf(os, ".(%d=>%d)", this->upc(), this->nupc());
     }

     PCStateBase *
     clone() const override
     {
         return new UPCState<InstWidth>(*this);
     }

     void
     set(Addr val)
     {
         Base::set(val);
         this->upc(0);
         this->nupc(1);
     }

     UPCState(const UPCState &other) : Base(other) {}
     UPCState &operator=(const UPCState &other) = default;
     UPCState() {}
     explicit UPCState(Addr val) { set(val); }

     bool
     branching() const
     {
         return this->npc() != this->pc() + InstWidth ||
                this->nupc() != this->upc() + 1;
     }

     // Advance the upc within the instruction.
     void
     uAdvance()
     {
         this->upc(this->nupc());
         this->nupc(this->nupc() + 1);
     }

     // End the macroop by resetting the upc and advancing the regular pc.
     void
     uEnd()
     {
         this->advance();
         this->upc(0);
         this->nupc(1);
     }
 };

 // A PC with a delay slot.
 template <int InstWidth>
 class DelaySlotPCState : public SimplePCState<InstWidth>
 {
   protected:
     typedef SimplePCState<InstWidth> Base;

     Addr _nnpc;

   public:
     void
     output(std::ostream &os) const override
     {
         ccprintf(os, "(%#x=>%#x=>%#x)", this->pc(), this->npc(), nnpc());
     }

     PCStateBase *
     clone() const override
     {
         return new DelaySlotPCState<InstWidth>(*this);
     }

     void
     update(const PCStateBase &other) override
     {
         Base::update(other);
         auto &pcstate = other.as<DelaySlotPCState<InstWidth>>();
         _nnpc = pcstate._nnpc;
     }

     Addr nnpc() const { return _nnpc; }
     void nnpc(Addr val) { _nnpc = val; }

     void
     set(Addr val)
     {
         Base::set(val);
         nnpc(val + 2 * InstWidth);
     }

     DelaySlotPCState(const DelaySlotPCState &other) :
         Base(other), _nnpc(other._nnpc)
     {}
     DelaySlotPCState &operator=(const DelaySlotPCState &other) = default;
     DelaySlotPCState() {}
     explicit DelaySlotPCState(Addr val) { set(val); }

     bool
     branching() const
     {
         return !(this->nnpc() == this->npc() + InstWidth &&
                  (this->npc() == this->pc() + InstWidth ||
                   this->npc() == this->pc() + 2 * InstWidth));
     }

     // Advance the PC.
     void
     advance()
     {
         this->_pc = this->_npc;
         this->_npc = this->_nnpc;
         this->_nnpc += InstWidth;
     }

     bool
     equals(const PCStateBase &other) const override
     {
         auto &ps = other.as<DelaySlotPCState<InstWidth>>();
         return Base::equals(other) && ps._nnpc == this->_nnpc;
     }

     void
     serialize(CheckpointOut &cp) const override
     {
         Base::serialize(cp);
         SERIALIZE_SCALAR(_nnpc);
     }

     void
     unserialize(CheckpointIn &cp) override
     {
         Base::unserialize(cp);
         UNSERIALIZE_SCALAR(_nnpc);
     }
 };

 // A PC with a delay slot and a microcode PC.
 template <int InstWidth>
 class DelaySlotUPCState : public DelaySlotPCState<InstWidth>
 {
   protected:
     typedef DelaySlotPCState<InstWidth> Base;

   public:
     void
     output(std::ostream &os) const override
     {
         Base::output(os);
         ccprintf(os, ".(%d=>%d)", this->upc(), this->nupc());
     }

     PCStateBase *
     clone() const override
     {
         return new DelaySlotUPCState<InstWidth>(*this);
     }

     void
     set(Addr val)
     {
         Base::set(val);
         this->upc(0);
         this->nupc(1);
     }

     DelaySlotUPCState(const DelaySlotUPCState &other) : Base(other) {}
     DelaySlotUPCState &operator=(const DelaySlotUPCState &other) = default;
     DelaySlotUPCState() {}
     explicit DelaySlotUPCState(Addr val) { set(val); }

     bool
     branching() const
     {
         return Base::branching() || this->nupc() != this->upc() + 1;
     }

     // Advance the upc within the instruction.
     void
     uAdvance()
     {
         this->_upc = this->_nupc;
         this->_nupc++;
     }

     // End the macroop by resetting the upc and advancing the regular pc.
     void
     uEnd()
     {
         this->advance();
         this->_upc = 0;
         this->_nupc = 1;
     }
 };

 }

 } // namespace gem5

 #endif
	/*
	* Copyright (c) 2020 ARM Limited
	* All rights reserved
	*
	* The license below extends only to copyright in the software and shall
	* not be construed as granting a license to any other intellectual
	* property including but not limited to intellectual property relating
	* to a hardware implementation of the functionality of the software
	* licensed hereunder. You may use the software subject to the license
	* terms below provided that you ensure that this notice is replicated
	* unmodified and in its entirety in all distributions of the software,
	* modified or unmodified, in source code or in binary form.
	*
	* Copyright (c) 2010 Gabe Black
	* 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 with the distribution;
	* neither the name of the copyright holders nor the names of its
	* contributors may be used to endorse or promote products derived from
	* this software without specific prior written permission.
	*
	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/

	#ifndef __ARCH_GENERIC_TYPES_HH__
	#define __ARCH_GENERIC_TYPES_HH__

	#include <iostream>
	#include <memory>
	#include <type_traits>

	#include "base/compiler.hh"
	#include "base/trace.hh"
	#include "base/types.hh"
	#include "sim/serialize.hh"

	namespace gem5
	{

	// The guaranteed interface.
	class PCStateBase : public Serializable
	{
	protected:
	Addr _pc = 0;
	MicroPC _upc = 0;

	PCStateBase(const PCStateBase &other) : _pc(other._pc), _upc(other._upc) {}
	PCStateBase &operator=(const PCStateBase &other) = default;
	PCStateBase() {}

	public:
	virtual ~PCStateBase() = default;

	template<class Target>
	Target &
	as()
	{
	return static_cast<Target &>(*this);
	}

	template<class Target>
	const Target &
	as() const
	{
	return static_cast<const Target &>(*this);
	}

	virtual PCStateBase *clone() const = 0;
	virtual void
	update(const PCStateBase &other)
	{
	_pc = other._pc;
	_upc = other._upc;
	}
	void update(const PCStateBase ptr) { update(ptr); }

	virtual void output(std::ostream &os) const = 0;

	virtual bool
	equals(const PCStateBase &other) const
	{
	return _pc == other._pc && _upc == other._upc;
	}

	/**
	* Returns the memory address of the instruction this PC points to.
	*
	* @return Memory address of the instruction this PC points to.
	*/
	Addr
	instAddr() const
	{
	return _pc;
	}

	/**
	* Returns the current micropc.
	*
	* @return The current micropc.
	*/
	MicroPC
	microPC() const
	{
	return _upc;
	}

	void
	serialize(CheckpointOut &cp) const override
	{
	SERIALIZE_SCALAR(_pc);
	SERIALIZE_SCALAR(_upc);
	}

	void
	unserialize(CheckpointIn &cp) override
	{
	UNSERIALIZE_SCALAR(_pc);
	UNSERIALIZE_SCALAR(_upc);
	}
	};

	static inline std::ostream &
	operator<<(std::ostream & os, const PCStateBase &pc)
	{
	pc.output(os);
	return os;
	}

	static inline bool
	operator==(const PCStateBase &a, const PCStateBase &b)
	{
	return a.equals(b);
	}

	static inline bool
	operator!=(const PCStateBase &a, const PCStateBase &b)
	{
	return !a.equals(b);
	}

	namespace
	{

	inline void
	set(PCStateBase &dest, const PCStateBase src)
	{
	if (GEM5_LIKELY(dest)) {
	if (GEM5_LIKELY(src)) {
	// Both src and dest already have storage, so just copy contents.
	dest->update(src);
	} else {
	// src is empty, so clear out dest.
	dest = nullptr;
	}
	} else {
	if (GEM5_LIKELY(src)) {
	// dest doesn't have storage, so create some as a copy of src.
	dest = src->clone();
	} else {
	// dest is already nullptr, so nothing to do.
	}
	}
	}

	inline void
	set(std::unique_ptr<PCStateBase> &dest, const PCStateBase *src)
	{
	PCStateBase *dest_ptr = dest.get();
	set(dest_ptr, src);
	if (dest.get() != dest_ptr)
	dest.reset(dest_ptr);
	}

	inline void
	set(PCStateBase *&dest, const std::unique_ptr<PCStateBase> &src)
	{
	const PCStateBase *src_ptr = src.get();
	set(dest, src_ptr);
	}

	inline void
	set(std::unique_ptr<PCStateBase> &dest,
	const std::unique_ptr<PCStateBase> &src)
	{
	PCStateBase *dest_ptr = dest.get();
	const PCStateBase *src_ptr = src.get();
	set(dest_ptr, src_ptr);
	if (dest.get() != dest_ptr)
	dest.reset(dest_ptr);
	}

	inline void
	set(PCStateBase *&dest, const PCStateBase &src)
	{
	if (GEM5_LIKELY(dest)) {
	// Update dest with the contents of src.
	dest->update(src);
	} else {
	// Clone src over to dest.
	dest = src.clone();
	}
	}

	inline void
	set(std::unique_ptr<PCStateBase> &dest, const PCStateBase &src)
	{
	PCStateBase *dest_ptr = dest.get();
	set(dest_ptr, src);
	if (dest.get() != dest_ptr)
	dest.reset(dest_ptr);
	}

	inline void
	set(PCStateBase &dest, const PCStateBase &src)
	{
	dest.update(src);
	}

	} // anonymous namespace

	namespace GenericISA
	{

	class PCStateCommon : public PCStateBase
	{
	protected:
	Addr _npc = 0;

	MicroPC _nupc = 1;

	PCStateCommon(const PCStateCommon &other) : PCStateBase(other),
	_npc(other._npc), _nupc(other._nupc)
	{}
	PCStateCommon &operator=(const PCStateCommon &other) = default;
	PCStateCommon() {}

	public:
	Addr pc() const { return _pc; }
	void pc(Addr val) { _pc = val; }

	Addr npc() const { return _npc; }
	void npc(Addr val) { _npc = val; }

	MicroPC upc() const { return _upc; }
	void upc(MicroPC val) { _upc = val; }

	MicroPC nupc() const { return _nupc; }
	void nupc(MicroPC val) { _nupc = val; }

	// Reset the macroop's upc without advancing the regular pc.
	void
	uReset()
	{
	_upc = 0;
	_nupc = 1;
	}

	void
	setNPC(Addr val)
	{
	npc(val);
	}

	void
	output(std::ostream &os) const override
	{
	ccprintf(os, "(%#x=>%#x)", this->pc(), this->npc());
	}

	void
	update(const PCStateBase &other) override
	{
	PCStateBase::update(other);
	auto &pcstate = other.as<PCStateCommon>();
	_npc = pcstate._npc;
	_nupc = pcstate._nupc;
	}

	bool
	equals(const PCStateBase &other) const override
	{
	auto &ps = other.as<PCStateCommon>();
	return PCStateBase::equals(other) &&
	_npc == ps._npc && _nupc == ps._nupc;
	}

	void
	serialize(CheckpointOut &cp) const override
	{
	PCStateBase::serialize(cp);
	SERIALIZE_SCALAR(_npc);
	SERIALIZE_SCALAR(_nupc);
	}

	void
	unserialize(CheckpointIn &cp) override
	{
	PCStateBase::unserialize(cp);
	UNSERIALIZE_SCALAR(_npc);
	UNSERIALIZE_SCALAR(_nupc);
	}
	};


	/*
	* Different flavors of PC state. Only ISA specific code should rely on
	* any particular type of PC state being available. All other code should
	* use the interface above.
	*/

	// The most basic type of PC.
	template <int InstWidth>
	class SimplePCState : public PCStateCommon
	{
	protected:
	typedef PCStateCommon Base;

	public:
	SimplePCState(const SimplePCState &other) : Base(other) {}
	SimplePCState &operator=(const SimplePCState &other) = default;
	SimplePCState() {}
	explicit SimplePCState(Addr val) { set(val); }

	PCStateBase *
	clone() const override
	{
	return new SimplePCState<InstWidth>(*this);
	}

	/**
	* Force this PC to reflect a particular value, resetting all its other
	* fields around it. This is useful for in place (re)initialization.
	*
	* @param val The value to set the PC to.
	*/
	void
	set(Addr val)
	{
	this->pc(val);
	this->npc(val + InstWidth);
	};

	bool
	branching() const
	{
	return this->npc() != this->pc() + InstWidth;
	}

	// Advance the PC.
	void
	advance()
	{
	this->_pc = this->_npc;
	this->_npc += InstWidth;
	}
	};

	// A PC and microcode PC.
	template <int InstWidth>
	class UPCState : public SimplePCState<InstWidth>
	{
	protected:
	typedef SimplePCState<InstWidth> Base;

	public:
	void
	output(std::ostream &os) const override
	{
	Base::output(os);
	ccprintf(os, ".(%d=>%d)", this->upc(), this->nupc());
	}

	PCStateBase *
	clone() const override
	{
	return new UPCState<InstWidth>(*this);
	}

	void
	set(Addr val)
	{
	Base::set(val);
	this->upc(0);
	this->nupc(1);
	}

	UPCState(const UPCState &other) : Base(other) {}
	UPCState &operator=(const UPCState &other) = default;
	UPCState() {}
	explicit UPCState(Addr val) { set(val); }

	bool
	branching() const
	{
	return this->npc() != this->pc() + InstWidth \|\|
	this->nupc() != this->upc() + 1;
	}

	// Advance the upc within the instruction.
	void
	uAdvance()
	{
	this->upc(this->nupc());
	this->nupc(this->nupc() + 1);
	}

	// End the macroop by resetting the upc and advancing the regular pc.
	void
	uEnd()
	{
	this->advance();
	this->upc(0);
	this->nupc(1);
	}
	};

	// A PC with a delay slot.
	template <int InstWidth>
	class DelaySlotPCState : public SimplePCState<InstWidth>
	{
	protected:
	typedef SimplePCState<InstWidth> Base;

	Addr _nnpc;

	public:
	void
	output(std::ostream &os) const override
	{
	ccprintf(os, "(%#x=>%#x=>%#x)", this->pc(), this->npc(), nnpc());
	}

	PCStateBase *
	clone() const override
	{
	return new DelaySlotPCState<InstWidth>(*this);
	}

	void
	update(const PCStateBase &other) override
	{
	Base::update(other);
	auto &pcstate = other.as<DelaySlotPCState<InstWidth>>();
	_nnpc = pcstate._nnpc;
	}

	Addr nnpc() const { return _nnpc; }
	void nnpc(Addr val) { _nnpc = val; }

	void
	set(Addr val)
	{
	Base::set(val);
	nnpc(val + 2 * InstWidth);
	}

	DelaySlotPCState(const DelaySlotPCState &other) :
	Base(other), _nnpc(other._nnpc)
	{}
	DelaySlotPCState &operator=(const DelaySlotPCState &other) = default;
	DelaySlotPCState() {}
	explicit DelaySlotPCState(Addr val) { set(val); }

	bool
	branching() const
	{
	return !(this->nnpc() == this->npc() + InstWidth &&
	(this->npc() == this->pc() + InstWidth \|\|
	this->npc() == this->pc() + 2 * InstWidth));
	}

	// Advance the PC.
	void
	advance()
	{
	this->_pc = this->_npc;
	this->_npc = this->_nnpc;
	this->_nnpc += InstWidth;
	}

	bool
	equals(const PCStateBase &other) const override
	{
	auto &ps = other.as<DelaySlotPCState<InstWidth>>();
	return Base::equals(other) && ps._nnpc == this->_nnpc;
	}

	void
	serialize(CheckpointOut &cp) const override
	{
	Base::serialize(cp);
	SERIALIZE_SCALAR(_nnpc);
	}

	void
	unserialize(CheckpointIn &cp) override
	{
	Base::unserialize(cp);
	UNSERIALIZE_SCALAR(_nnpc);
	}
	};

	// A PC with a delay slot and a microcode PC.
	template <int InstWidth>
	class DelaySlotUPCState : public DelaySlotPCState<InstWidth>
	{
	protected:
	typedef DelaySlotPCState<InstWidth> Base;

	public:
	void
	output(std::ostream &os) const override
	{
	Base::output(os);
	ccprintf(os, ".(%d=>%d)", this->upc(), this->nupc());
	}

	PCStateBase *
	clone() const override
	{
	return new DelaySlotUPCState<InstWidth>(*this);
	}

	void
	set(Addr val)
	{
	Base::set(val);
	this->upc(0);
	this->nupc(1);
	}

	DelaySlotUPCState(const DelaySlotUPCState &other) : Base(other) {}
	DelaySlotUPCState &operator=(const DelaySlotUPCState &other) = default;
	DelaySlotUPCState() {}
	explicit DelaySlotUPCState(Addr val) { set(val); }

	bool
	branching() const
	{
	return Base::branching() \|\| this->nupc() != this->upc() + 1;
	}

	// Advance the upc within the instruction.
	void
	uAdvance()
	{
	this->_upc = this->_nupc;
	this->_nupc++;
	}

	// End the macroop by resetting the upc and advancing the regular pc.
	void
	uEnd()
	{
	this->advance();
	this->_upc = 0;
	this->_nupc = 1;
	}
	};

	}

	} // namespace gem5

	#endif