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/*
* Copyright (c) 2015-2017 Advanced Micro Devices, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2. 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.
*
* 3. Neither the name of the copyright holder 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 HOLDER 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 __REGISTER_FILE_HH__
#define __REGISTER_FILE_HH__
#include <limits>
#include <vector>
#include "base/statistics.hh"
#include "base/types.hh"
#include "gpu-compute/misc.hh"
#include "sim/sim_object.hh"
namespace gem5
{
class ComputeUnit;
class Shader;
class PoolManager;
class Wavefront;
struct RegisterFileParams;
// Abstract Register File
// This register file class can be inherited from to create both
// scalar and vector register files.
class RegisterFile : public SimObject
{
public:
RegisterFile(const RegisterFileParams &p);
virtual ~RegisterFile();
virtual void setParent(ComputeUnit *_computeUnit);
int numRegs() const { return _numRegs; }
// State functions
// Scoreboard functions
virtual bool operandsReady(Wavefront *w, GPUDynInstPtr ii) const;
virtual bool regBusy(int idx) const;
virtual void markReg(int regIdx, bool value);
// Abstract Register Event
class RegisterEvent : public Event
{
protected:
RegisterFile *rf;
int regIdx;
public:
RegisterEvent(RegisterFile *_rf, int _regIdx)
: rf(_rf), regIdx(_regIdx) { setFlags(AutoDelete); }
};
// Register Event to mark a register as free in the scoreboard/busy vector
class MarkRegFreeScbEvent : public RegisterEvent
{
public:
MarkRegFreeScbEvent(RegisterFile *_rf, int _regIdx)
: RegisterEvent(_rf, _regIdx) { }
void process();
};
// Register Event to mark a register as busy in the scoreboard/busy vector
class MarkRegBusyScbEvent : public RegisterEvent
{
public:
MarkRegBusyScbEvent(RegisterFile *_rf, int _regIdx)
: RegisterEvent(_rf, _regIdx) { }
void process();
};
// Schedule an event to mark a register as free/busy in
// the scoreboard/busy vector. Delay is already in Ticks
virtual void enqRegFreeEvent(uint32_t regIdx, uint64_t delay);
virtual void enqRegBusyEvent(uint32_t regIdx, uint64_t delay);
// Schedule functions
// The following functions are called by the SCH stage when attempting
// to move a wave from the readyList to the schList.
// canSchedule* checks if the RF is ready to provide operands for
// the instruction, while schedule* requests the RF to begin reading
// and writing of operands. Calling schedule* may only occur
// immediately after canSchedule* was called and returned True
virtual bool canScheduleReadOperands(Wavefront *w, GPUDynInstPtr ii);
virtual bool canScheduleWriteOperands(Wavefront *w, GPUDynInstPtr ii);
virtual void scheduleReadOperands(Wavefront *w, GPUDynInstPtr ii);
virtual void scheduleWriteOperands(Wavefront *w, GPUDynInstPtr ii);
// The following function is called to check if all operands
// have been read for the given instruction
virtual bool operandReadComplete(Wavefront *w, GPUDynInstPtr ii);
// The following two functions are only called by returning loads to
// check if the register file can support the incoming writes
virtual bool canScheduleWriteOperandsFromLoad(Wavefront *w,
GPUDynInstPtr ii);
// Queue the register writes. Assumes canScheduleWriteOperandsFromLoad
// was called immediately prior and returned True
virtual void scheduleWriteOperandsFromLoad(Wavefront *w,
GPUDynInstPtr ii);
// ExecRF is invoked every cycle by the compute unit and may be
// used to model detailed timing of the register file.
virtual void exec();
// Called to inform RF that an instruction is executing
// to schedule events for writeback, etc., as needed
virtual void waveExecuteInst(Wavefront *w, GPUDynInstPtr ii);
// Debug functions
virtual std::string dump() const;
virtual void dispatchInstruction(GPUDynInstPtr ii);
protected:
ComputeUnit* computeUnit;
int simdId;
// flag indicating if a register is busy
std::vector<bool> busy;
// numer of registers in this register file
int _numRegs;
struct RegisterFileStats : public statistics::Group
{
RegisterFileStats(statistics::Group *parent);
// Total number of register reads per DWORD per thread
statistics::Scalar registerReads;
// Total number of register writes per DWORD per thread
statistics::Scalar registerWrites;
// Number of register file SRAM activations for reads.
// The register file may be implemented with multiple SRAMs. This stat
// tracks how many times the SRAMs are accessed for reads.
statistics::Scalar sramReads;
// Number of register file SRAM activations for writes
statistics::Scalar sramWrites;
} stats;
};
} // namespace gem5
#endif // __REGISTER_FILE_HH__