src/cpu/simple_thread.hh - amd/gem5 - Git at Google

 /*
  * Copyright (c) 2001-2006 The Regents of The University of Michigan
  * 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.
  *
  * Authors: Steve Reinhardt
  *          Nathan Binkert
  */

 #ifndef __CPU_SIMPLE_THREAD_HH__
 #define __CPU_SIMPLE_THREAD_HH__

 #include "arch/isa.hh"
 #include "arch/isa_traits.hh"
 #include "arch/registers.hh"
 #include "arch/tlb.hh"
 #include "arch/types.hh"
 #include "base/types.hh"
 #include "config/full_system.hh"
 #include "config/the_isa.hh"
 #include "cpu/thread_context.hh"
 #include "cpu/thread_state.hh"
 #include "mem/request.hh"
 #include "sim/byteswap.hh"
 #include "sim/eventq.hh"
 #include "sim/serialize.hh"

 class BaseCPU;

 #if FULL_SYSTEM

 #include "sim/system.hh"

 class FunctionProfile;
 class ProfileNode;
 class FunctionalPort;
 class PhysicalPort;

 namespace TheISA {
     namespace Kernel {
         class Statistics;
     };
 };

 #else // !FULL_SYSTEM

 #include "sim/process.hh"
 #include "mem/page_table.hh"
 class TranslatingPort;

 #endif // FULL_SYSTEM

 /**
  * The SimpleThread object provides a combination of the ThreadState
  * object and the ThreadContext interface. It implements the
  * ThreadContext interface so that a ProxyThreadContext class can be
  * made using SimpleThread as the template parameter (see
  * thread_context.hh). It adds to the ThreadState object by adding all
  * the objects needed for simple functional execution, including a
  * simple architectural register file, and pointers to the ITB and DTB
  * in full system mode. For CPU models that do not need more advanced
  * ways to hold state (i.e. a separate physical register file, or
  * separate fetch and commit PC's), this SimpleThread class provides
  * all the necessary state for full architecture-level functional
  * simulation.  See the AtomicSimpleCPU or TimingSimpleCPU for
  * examples.
  */

 class SimpleThread : public ThreadState
 {
   protected:
     typedef TheISA::MachInst MachInst;
     typedef TheISA::MiscReg MiscReg;
     typedef TheISA::FloatReg FloatReg;
     typedef TheISA::FloatRegBits FloatRegBits;
   public:
     typedef ThreadContext::Status Status;

   protected:
     union {
         FloatReg f[TheISA::NumFloatRegs];
         FloatRegBits i[TheISA::NumFloatRegs];
     } floatRegs;
     TheISA::IntReg intRegs[TheISA::NumIntRegs];
     TheISA::ISA isa;    // one "instance" of the current ISA.

     /** The current microcode pc for the currently executing macro
      * operation.
      */
     MicroPC microPC;

     /** The next microcode pc for the currently executing macro
      * operation.
      */
     MicroPC nextMicroPC;

     /** The current pc.
      */
     Addr PC;

     /** The next pc.
      */
     Addr nextPC;

     /** The next next pc.
      */
     Addr nextNPC;

   public:
     // pointer to CPU associated with this SimpleThread
     BaseCPU *cpu;

     ProxyThreadContext<SimpleThread> *tc;

     System *system;

     TheISA::TLB *itb;
     TheISA::TLB *dtb;

     // constructor: initialize SimpleThread from given process structure
 #if FULL_SYSTEM
     SimpleThread(BaseCPU *_cpu, int _thread_num, System *_system,
                  TheISA::TLB *_itb, TheISA::TLB *_dtb,
                  bool use_kernel_stats = true);
 #else
     SimpleThread(BaseCPU *_cpu, int _thread_num, Process *_process,
                  TheISA::TLB *_itb, TheISA::TLB *_dtb);
 #endif

     SimpleThread();

     virtual ~SimpleThread();

     virtual void takeOverFrom(ThreadContext *oldContext);

     void regStats(const std::string &name);

     void copyTC(ThreadContext *context);

     void copyState(ThreadContext *oldContext);

     void serialize(std::ostream &os);
     void unserialize(Checkpoint *cp, const std::string &section);

     /***************************************************************
      *  SimpleThread functions to provide CPU with access to various
      *  state.
      **************************************************************/

     /** Returns the pointer to this SimpleThread's ThreadContext. Used
      *  when a ThreadContext must be passed to objects outside of the
      *  CPU.
      */
     ThreadContext *getTC() { return tc; }

     void demapPage(Addr vaddr, uint64_t asn)
     {
         itb->demapPage(vaddr, asn);
         dtb->demapPage(vaddr, asn);
     }

     void demapInstPage(Addr vaddr, uint64_t asn)
     {
         itb->demapPage(vaddr, asn);
     }

     void demapDataPage(Addr vaddr, uint64_t asn)
     {
         dtb->demapPage(vaddr, asn);
     }

 #if FULL_SYSTEM
     void dumpFuncProfile();

     Fault hwrei();

     bool simPalCheck(int palFunc);

 #endif

     /*******************************************
      * ThreadContext interface functions.
      ******************************************/

     BaseCPU *getCpuPtr() { return cpu; }

     TheISA::TLB *getITBPtr() { return itb; }

     TheISA::TLB *getDTBPtr() { return dtb; }

     System *getSystemPtr() { return system; }

 #if FULL_SYSTEM
     FunctionalPort *getPhysPort() { return physPort; }

     /** Return a virtual port. This port cannot be cached locally in an object.
      * After a CPU switch it may point to the wrong memory object which could
      * mean stale data.
      */
     VirtualPort *getVirtPort() { return virtPort; }
 #endif

     Status status() const { return _status; }

     void setStatus(Status newStatus) { _status = newStatus; }

     /// Set the status to Active.  Optional delay indicates number of
     /// cycles to wait before beginning execution.
     void activate(int delay = 1);

     /// Set the status to Suspended.
     void suspend();

     /// Set the status to Halted.
     void halt();

     virtual bool misspeculating();

     Fault instRead(RequestPtr &req)
     {
         panic("instRead not implemented");
         // return funcPhysMem->read(req, inst);
         return NoFault;
     }

     void copyArchRegs(ThreadContext *tc);

     void clearArchRegs()
     {
         microPC = 0;
         nextMicroPC = 1;
         PC = nextPC = nextNPC = 0;
         memset(intRegs, 0, sizeof(intRegs));
         memset(floatRegs.i, 0, sizeof(floatRegs.i));
         isa.clear();
     }

     //
     // New accessors for new decoder.
     //
     uint64_t readIntReg(int reg_idx)
     {
         int flatIndex = isa.flattenIntIndex(reg_idx);
         assert(flatIndex < TheISA::NumIntRegs);
         uint64_t regVal = intRegs[flatIndex];
         DPRINTF(IntRegs, "Reading int reg %d as %#x.\n", reg_idx, regVal);
         return regVal;
     }

     FloatReg readFloatReg(int reg_idx)
     {
         int flatIndex = isa.flattenFloatIndex(reg_idx);
         assert(flatIndex < TheISA::NumFloatRegs);
         FloatReg regVal = floatRegs.f[flatIndex];
         DPRINTF(FloatRegs, "Reading float reg %d as %f, %#x.\n",
                 reg_idx, regVal, floatRegs.i[flatIndex]);
         return regVal;
     }

     FloatRegBits readFloatRegBits(int reg_idx)
     {
         int flatIndex = isa.flattenFloatIndex(reg_idx);
         assert(flatIndex < TheISA::NumFloatRegs);
         FloatRegBits regVal = floatRegs.i[flatIndex];
         DPRINTF(FloatRegs, "Reading float reg %d bits as %#x, %f.\n",
                 reg_idx, regVal, floatRegs.f[flatIndex]);
         return regVal;
     }

     void setIntReg(int reg_idx, uint64_t val)
     {
         int flatIndex = isa.flattenIntIndex(reg_idx);
         assert(flatIndex < TheISA::NumIntRegs);
         DPRINTF(IntRegs, "Setting int reg %d to %#x.\n", reg_idx, val);
         intRegs[flatIndex] = val;
     }

     void setFloatReg(int reg_idx, FloatReg val)
     {
         int flatIndex = isa.flattenFloatIndex(reg_idx);
         assert(flatIndex < TheISA::NumFloatRegs);
         floatRegs.f[flatIndex] = val;
         DPRINTF(FloatRegs, "Setting float reg %d to %f, %#x.\n",
                 reg_idx, val, floatRegs.i[flatIndex]);
     }

     void setFloatRegBits(int reg_idx, FloatRegBits val)
     {
         int flatIndex = isa.flattenFloatIndex(reg_idx);
         assert(flatIndex < TheISA::NumFloatRegs);
         floatRegs.i[flatIndex] = val;
         DPRINTF(FloatRegs, "Setting float reg %d bits to %#x, %#f.\n",
                 reg_idx, val, floatRegs.f[flatIndex]);
     }

     uint64_t readPC()
     {
         return PC;
     }

     void setPC(uint64_t val)
     {
         PC = val;
     }

     uint64_t readMicroPC()
     {
         return microPC;
     }

     void setMicroPC(uint64_t val)
     {
         microPC = val;
     }

     uint64_t readNextPC()
     {
         return nextPC;
     }

     void setNextPC(uint64_t val)
     {
         nextPC = val;
     }

     uint64_t readNextMicroPC()
     {
         return nextMicroPC;
     }

     void setNextMicroPC(uint64_t val)
     {
         nextMicroPC = val;
     }

     uint64_t readNextNPC()
     {
 #if ISA_HAS_DELAY_SLOT
         return nextNPC;
 #else
         return nextPC + sizeof(TheISA::MachInst);
 #endif
     }

     void setNextNPC(uint64_t val)
     {
 #if ISA_HAS_DELAY_SLOT
         nextNPC = val;
 #endif
     }

     MiscReg
     readMiscRegNoEffect(int misc_reg, ThreadID tid = 0)
     {
         return isa.readMiscRegNoEffect(misc_reg);
     }

     MiscReg
     readMiscReg(int misc_reg, ThreadID tid = 0)
     {
         return isa.readMiscReg(misc_reg, tc);
     }

     void
     setMiscRegNoEffect(int misc_reg, const MiscReg &val, ThreadID tid = 0)
     {
         return isa.setMiscRegNoEffect(misc_reg, val);
     }

     void
     setMiscReg(int misc_reg, const MiscReg &val, ThreadID tid = 0)
     {
         return isa.setMiscReg(misc_reg, val, tc);
     }

     int
     flattenIntIndex(int reg)
     {
         return isa.flattenIntIndex(reg);
     }

     int
     flattenFloatIndex(int reg)
     {
         return isa.flattenFloatIndex(reg);
     }

     unsigned readStCondFailures() { return storeCondFailures; }

     void setStCondFailures(unsigned sc_failures)
     { storeCondFailures = sc_failures; }

 #if !FULL_SYSTEM
     void syscall(int64_t callnum)
     {
         process->syscall(callnum, tc);
     }
 #endif
 };


 // for non-speculative execution context, spec_mode is always false
 inline bool
 SimpleThread::misspeculating()
 {
     return false;
 }

 #endif // __CPU_CPU_EXEC_CONTEXT_HH__
	/*
	* Copyright (c) 2001-2006 The Regents of The University of Michigan
	* 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.
	*
	* Authors: Steve Reinhardt
	* Nathan Binkert
	*/

	#ifndef __CPU_SIMPLE_THREAD_HH__
	#define __CPU_SIMPLE_THREAD_HH__

	#include "arch/isa.hh"
	#include "arch/isa_traits.hh"
	#include "arch/registers.hh"
	#include "arch/tlb.hh"
	#include "arch/types.hh"
	#include "base/types.hh"
	#include "config/full_system.hh"
	#include "config/the_isa.hh"
	#include "cpu/thread_context.hh"
	#include "cpu/thread_state.hh"
	#include "mem/request.hh"
	#include "sim/byteswap.hh"
	#include "sim/eventq.hh"
	#include "sim/serialize.hh"

	class BaseCPU;

	#if FULL_SYSTEM

	#include "sim/system.hh"

	class FunctionProfile;
	class ProfileNode;
	class FunctionalPort;
	class PhysicalPort;

	namespace TheISA {
	namespace Kernel {
	class Statistics;
	};
	};

	#else // !FULL_SYSTEM

	#include "sim/process.hh"
	#include "mem/page_table.hh"
	class TranslatingPort;

	#endif // FULL_SYSTEM

	/**
	* The SimpleThread object provides a combination of the ThreadState
	* object and the ThreadContext interface. It implements the
	* ThreadContext interface so that a ProxyThreadContext class can be
	* made using SimpleThread as the template parameter (see
	* thread_context.hh). It adds to the ThreadState object by adding all
	* the objects needed for simple functional execution, including a
	* simple architectural register file, and pointers to the ITB and DTB
	* in full system mode. For CPU models that do not need more advanced
	* ways to hold state (i.e. a separate physical register file, or
	* separate fetch and commit PC's), this SimpleThread class provides
	* all the necessary state for full architecture-level functional
	* simulation. See the AtomicSimpleCPU or TimingSimpleCPU for
	* examples.
	*/

	class SimpleThread : public ThreadState
	{
	protected:
	typedef TheISA::MachInst MachInst;
	typedef TheISA::MiscReg MiscReg;
	typedef TheISA::FloatReg FloatReg;
	typedef TheISA::FloatRegBits FloatRegBits;
	public:
	typedef ThreadContext::Status Status;

	protected:
	union {
	FloatReg f[TheISA::NumFloatRegs];
	FloatRegBits i[TheISA::NumFloatRegs];
	} floatRegs;
	TheISA::IntReg intRegs[TheISA::NumIntRegs];
	TheISA::ISA isa; // one "instance" of the current ISA.

	/** The current microcode pc for the currently executing macro
	* operation.
	*/
	MicroPC microPC;

	/** The next microcode pc for the currently executing macro
	* operation.
	*/
	MicroPC nextMicroPC;

	/** The current pc.
	*/
	Addr PC;

	/** The next pc.
	*/
	Addr nextPC;

	/** The next next pc.
	*/
	Addr nextNPC;

	public:
	// pointer to CPU associated with this SimpleThread
	BaseCPU *cpu;

	ProxyThreadContext<SimpleThread> *tc;

	System *system;

	TheISA::TLB *itb;
	TheISA::TLB *dtb;

	// constructor: initialize SimpleThread from given process structure
	#if FULL_SYSTEM
	SimpleThread(BaseCPU _cpu, int _thread_num, System _system,
	TheISA::TLB _itb, TheISA::TLB _dtb,
	bool use_kernel_stats = true);
	#else
	SimpleThread(BaseCPU _cpu, int _thread_num, Process _process,
	TheISA::TLB _itb, TheISA::TLB _dtb);
	#endif

	SimpleThread();

	virtual ~SimpleThread();

	virtual void takeOverFrom(ThreadContext *oldContext);

	void regStats(const std::string &name);

	void copyTC(ThreadContext *context);

	void copyState(ThreadContext *oldContext);

	void serialize(std::ostream &os);
	void unserialize(Checkpoint *cp, const std::string &section);

	/***************************************************************
	* SimpleThread functions to provide CPU with access to various
	* state.
	**************************************************************/

	/** Returns the pointer to this SimpleThread's ThreadContext. Used
	* when a ThreadContext must be passed to objects outside of the
	* CPU.
	*/
	ThreadContext *getTC() { return tc; }

	void demapPage(Addr vaddr, uint64_t asn)
	{
	itb->demapPage(vaddr, asn);
	dtb->demapPage(vaddr, asn);
	}

	void demapInstPage(Addr vaddr, uint64_t asn)
	{
	itb->demapPage(vaddr, asn);
	}

	void demapDataPage(Addr vaddr, uint64_t asn)
	{
	dtb->demapPage(vaddr, asn);
	}

	#if FULL_SYSTEM
	void dumpFuncProfile();

	Fault hwrei();

	bool simPalCheck(int palFunc);

	#endif

	/*******************************************
	* ThreadContext interface functions.
	******************************************/

	BaseCPU *getCpuPtr() { return cpu; }

	TheISA::TLB *getITBPtr() { return itb; }

	TheISA::TLB *getDTBPtr() { return dtb; }

	System *getSystemPtr() { return system; }

	#if FULL_SYSTEM
	FunctionalPort *getPhysPort() { return physPort; }

	/** Return a virtual port. This port cannot be cached locally in an object.
	* After a CPU switch it may point to the wrong memory object which could
	* mean stale data.
	*/
	VirtualPort *getVirtPort() { return virtPort; }
	#endif

	Status status() const { return _status; }

	void setStatus(Status newStatus) { _status = newStatus; }

	/// Set the status to Active. Optional delay indicates number of
	/// cycles to wait before beginning execution.
	void activate(int delay = 1);

	/// Set the status to Suspended.
	void suspend();

	/// Set the status to Halted.
	void halt();

	virtual bool misspeculating();

	Fault instRead(RequestPtr &req)
	{
	panic("instRead not implemented");
	// return funcPhysMem->read(req, inst);
	return NoFault;
	}

	void copyArchRegs(ThreadContext *tc);

	void clearArchRegs()
	{
	microPC = 0;
	nextMicroPC = 1;
	PC = nextPC = nextNPC = 0;
	memset(intRegs, 0, sizeof(intRegs));
	memset(floatRegs.i, 0, sizeof(floatRegs.i));
	isa.clear();
	}

	//
	// New accessors for new decoder.
	//
	uint64_t readIntReg(int reg_idx)
	{
	int flatIndex = isa.flattenIntIndex(reg_idx);
	assert(flatIndex < TheISA::NumIntRegs);
	uint64_t regVal = intRegs[flatIndex];
	DPRINTF(IntRegs, "Reading int reg %d as %#x.\n", reg_idx, regVal);
	return regVal;
	}

	FloatReg readFloatReg(int reg_idx)
	{
	int flatIndex = isa.flattenFloatIndex(reg_idx);
	assert(flatIndex < TheISA::NumFloatRegs);
	FloatReg regVal = floatRegs.f[flatIndex];
	DPRINTF(FloatRegs, "Reading float reg %d as %f, %#x.\n",
	reg_idx, regVal, floatRegs.i[flatIndex]);
	return regVal;
	}

	FloatRegBits readFloatRegBits(int reg_idx)
	{
	int flatIndex = isa.flattenFloatIndex(reg_idx);
	assert(flatIndex < TheISA::NumFloatRegs);
	FloatRegBits regVal = floatRegs.i[flatIndex];
	DPRINTF(FloatRegs, "Reading float reg %d bits as %#x, %f.\n",
	reg_idx, regVal, floatRegs.f[flatIndex]);
	return regVal;
	}

	void setIntReg(int reg_idx, uint64_t val)
	{
	int flatIndex = isa.flattenIntIndex(reg_idx);
	assert(flatIndex < TheISA::NumIntRegs);
	DPRINTF(IntRegs, "Setting int reg %d to %#x.\n", reg_idx, val);
	intRegs[flatIndex] = val;
	}

	void setFloatReg(int reg_idx, FloatReg val)
	{
	int flatIndex = isa.flattenFloatIndex(reg_idx);
	assert(flatIndex < TheISA::NumFloatRegs);
	floatRegs.f[flatIndex] = val;
	DPRINTF(FloatRegs, "Setting float reg %d to %f, %#x.\n",
	reg_idx, val, floatRegs.i[flatIndex]);
	}

	void setFloatRegBits(int reg_idx, FloatRegBits val)
	{
	int flatIndex = isa.flattenFloatIndex(reg_idx);
	assert(flatIndex < TheISA::NumFloatRegs);
	floatRegs.i[flatIndex] = val;
	DPRINTF(FloatRegs, "Setting float reg %d bits to %#x, %#f.\n",
	reg_idx, val, floatRegs.f[flatIndex]);
	}

	uint64_t readPC()
	{
	return PC;
	}

	void setPC(uint64_t val)
	{
	PC = val;
	}

	uint64_t readMicroPC()
	{
	return microPC;
	}

	void setMicroPC(uint64_t val)
	{
	microPC = val;
	}

	uint64_t readNextPC()
	{
	return nextPC;
	}

	void setNextPC(uint64_t val)
	{
	nextPC = val;
	}

	uint64_t readNextMicroPC()
	{
	return nextMicroPC;
	}

	void setNextMicroPC(uint64_t val)
	{
	nextMicroPC = val;
	}

	uint64_t readNextNPC()
	{
	#if ISA_HAS_DELAY_SLOT
	return nextNPC;
	#else
	return nextPC + sizeof(TheISA::MachInst);
	#endif
	}

	void setNextNPC(uint64_t val)
	{
	#if ISA_HAS_DELAY_SLOT
	nextNPC = val;
	#endif
	}

	MiscReg
	readMiscRegNoEffect(int misc_reg, ThreadID tid = 0)
	{
	return isa.readMiscRegNoEffect(misc_reg);
	}

	MiscReg
	readMiscReg(int misc_reg, ThreadID tid = 0)
	{
	return isa.readMiscReg(misc_reg, tc);
	}

	void
	setMiscRegNoEffect(int misc_reg, const MiscReg &val, ThreadID tid = 0)
	{
	return isa.setMiscRegNoEffect(misc_reg, val);
	}

	void
	setMiscReg(int misc_reg, const MiscReg &val, ThreadID tid = 0)
	{
	return isa.setMiscReg(misc_reg, val, tc);
	}

	int
	flattenIntIndex(int reg)
	{
	return isa.flattenIntIndex(reg);
	}

	int
	flattenFloatIndex(int reg)
	{
	return isa.flattenFloatIndex(reg);
	}

	unsigned readStCondFailures() { return storeCondFailures; }

	void setStCondFailures(unsigned sc_failures)
	{ storeCondFailures = sc_failures; }

	#if !FULL_SYSTEM
	void syscall(int64_t callnum)
	{
	process->syscall(callnum, tc);
	}
	#endif
	};


	// for non-speculative execution context, spec_mode is always false
	inline bool
	SimpleThread::misspeculating()
	{
	return false;
	}

	#endif // __CPU_CPU_EXEC_CONTEXT_HH__