src/cpu/o3/comm.hh - public/gem5 - Git at Google

 /*
  * Copyright (c) 2011, 2016-2017 ARM Limited
  * Copyright (c) 2013 Advanced Micro Devices, Inc.
  * 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) 2004-2006 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.
  */

 #ifndef __CPU_O3_COMM_HH__
 #define __CPU_O3_COMM_HH__

 #include <vector>

 #include "arch/generic/pcstate.hh"
 #include "base/types.hh"
 #include "cpu/inst_seq.hh"
 #include "cpu/o3/dyn_inst_ptr.hh"
 #include "cpu/o3/limits.hh"
 #include "sim/faults.hh"

 namespace gem5
 {

 namespace o3
 {

 /** Struct that defines the information passed from fetch to decode. */
 struct FetchStruct
 {
     int size;

     DynInstPtr insts[MaxWidth];
     Fault fetchFault;
     InstSeqNum fetchFaultSN;
     bool clearFetchFault;
 };

 /** Struct that defines the information passed from decode to rename. */
 struct DecodeStruct
 {
     int size;

     DynInstPtr insts[MaxWidth];
 };

 /** Struct that defines the information passed from rename to IEW. */
 struct RenameStruct
 {
     int size;

     DynInstPtr insts[MaxWidth];
 };

 /** Struct that defines the information passed from IEW to commit. */
 struct IEWStruct
 {
     int size;

     DynInstPtr insts[MaxWidth];
     DynInstPtr mispredictInst[MaxThreads];
     Addr mispredPC[MaxThreads];
     InstSeqNum squashedSeqNum[MaxThreads];
     std::unique_ptr<PCStateBase> pc[MaxThreads];

     bool squash[MaxThreads];
     bool branchMispredict[MaxThreads];
     bool branchTaken[MaxThreads];
     bool includeSquashInst[MaxThreads];
 };

 struct IssueStruct
 {
     int size;

     DynInstPtr insts[MaxWidth];
 };

 /** Struct that defines all backwards communication. */
 struct TimeStruct
 {
     struct DecodeComm
     {
         std::unique_ptr<PCStateBase> nextPC;
         DynInstPtr mispredictInst;
         DynInstPtr squashInst;
         InstSeqNum doneSeqNum;
         Addr mispredPC;
         uint64_t branchAddr;
         unsigned branchCount;
         bool squash;
         bool predIncorrect;
         bool branchMispredict;
         bool branchTaken;
     };

     DecodeComm decodeInfo[MaxThreads];

     struct RenameComm {};

     RenameComm renameInfo[MaxThreads];

     struct IewComm
     {
         // Also eventually include skid buffer space.
         unsigned freeIQEntries;
         unsigned freeLQEntries;
         unsigned freeSQEntries;
         unsigned dispatchedToLQ;
         unsigned dispatchedToSQ;

         unsigned iqCount;
         unsigned ldstqCount;

         unsigned dispatched;
         bool usedIQ;
         bool usedLSQ;
     };

     IewComm iewInfo[MaxThreads];

     struct CommitComm
     {
         /////////////////////////////////////////////////////////////////////
         // This code has been re-structured for better packing of variables
         // instead of by stage which is the more logical way to arrange the
         // data.
         // F = Fetch
         // D = Decode
         // I = IEW
         // R = Rename
         // As such each member is annotated with who consumes it
         // e.g. bool variable name // *F,R for Fetch and Rename
         /////////////////////////////////////////////////////////////////////

         /// The pc of the next instruction to execute. This is the next
         /// instruction for a branch mispredict, but the same instruction for
         /// order violation and the like
         std::unique_ptr<PCStateBase> pc; // *F

         /// Provide fetch the instruction that mispredicted, if this
         /// pointer is not-null a misprediction occured
         DynInstPtr mispredictInst;  // *F

         /// Instruction that caused the a non-mispredict squash
         DynInstPtr squashInst; // *F

         /// Hack for now to send back a strictly ordered access to the
         /// IEW stage.
         DynInstPtr strictlyOrderedLoad; // *I

         /// Communication specifically to the IQ to tell the IQ that it can
         /// schedule a non-speculative instruction.
         InstSeqNum nonSpecSeqNum; // *I

         /// Represents the instruction that has either been retired or
         /// squashed.  Similar to having a single bus that broadcasts the
         /// retired or squashed sequence number.
         InstSeqNum doneSeqNum; // *F, I

         /// Tell Rename how many free entries it has in the ROB
         unsigned freeROBEntries; // *R

         bool squash; // *F, D, R, I
         bool robSquashing; // *F, D, R, I

         /// Rename should re-read number of free rob entries
         bool usedROB; // *R

         /// Notify Rename that the ROB is empty
         bool emptyROB; // *R

         /// Was the branch taken or not
         bool branchTaken; // *F
         /// If an interrupt is pending and fetch should stall
         bool interruptPending; // *F
         /// If the interrupt ended up being cleared before being handled
         bool clearInterrupt; // *F

         /// Hack for now to send back an strictly ordered access to
         /// the IEW stage.
         bool strictlyOrdered; // *I

     };

     CommitComm commitInfo[MaxThreads];

     bool decodeBlock[MaxThreads];
     bool decodeUnblock[MaxThreads];
     bool renameBlock[MaxThreads];
     bool renameUnblock[MaxThreads];
     bool iewBlock[MaxThreads];
     bool iewUnblock[MaxThreads];
 };

 } // namespace o3
 } // namespace gem5

 #endif //__CPU_O3_COMM_HH__
	/*
	* Copyright (c) 2011, 2016-2017 ARM Limited
	* Copyright (c) 2013 Advanced Micro Devices, Inc.
	* 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) 2004-2006 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.
	*/

	#ifndef __CPU_O3_COMM_HH__
	#define __CPU_O3_COMM_HH__

	#include <vector>

	#include "arch/generic/pcstate.hh"
	#include "base/types.hh"
	#include "cpu/inst_seq.hh"
	#include "cpu/o3/dyn_inst_ptr.hh"
	#include "cpu/o3/limits.hh"
	#include "sim/faults.hh"

	namespace gem5
	{

	namespace o3
	{

	/** Struct that defines the information passed from fetch to decode. */
	struct FetchStruct
	{
	int size;

	DynInstPtr insts[MaxWidth];
	Fault fetchFault;
	InstSeqNum fetchFaultSN;
	bool clearFetchFault;
	};

	/** Struct that defines the information passed from decode to rename. */
	struct DecodeStruct
	{
	int size;

	DynInstPtr insts[MaxWidth];
	};

	/** Struct that defines the information passed from rename to IEW. */
	struct RenameStruct
	{
	int size;

	DynInstPtr insts[MaxWidth];
	};

	/** Struct that defines the information passed from IEW to commit. */
	struct IEWStruct
	{
	int size;

	DynInstPtr insts[MaxWidth];
	DynInstPtr mispredictInst[MaxThreads];
	Addr mispredPC[MaxThreads];
	InstSeqNum squashedSeqNum[MaxThreads];
	std::unique_ptr<PCStateBase> pc[MaxThreads];

	bool squash[MaxThreads];
	bool branchMispredict[MaxThreads];
	bool branchTaken[MaxThreads];
	bool includeSquashInst[MaxThreads];
	};

	struct IssueStruct
	{
	int size;

	DynInstPtr insts[MaxWidth];
	};

	/** Struct that defines all backwards communication. */
	struct TimeStruct
	{
	struct DecodeComm
	{
	std::unique_ptr<PCStateBase> nextPC;
	DynInstPtr mispredictInst;
	DynInstPtr squashInst;
	InstSeqNum doneSeqNum;
	Addr mispredPC;
	uint64_t branchAddr;
	unsigned branchCount;
	bool squash;
	bool predIncorrect;
	bool branchMispredict;
	bool branchTaken;
	};

	DecodeComm decodeInfo[MaxThreads];

	struct RenameComm {};

	RenameComm renameInfo[MaxThreads];

	struct IewComm
	{
	// Also eventually include skid buffer space.
	unsigned freeIQEntries;
	unsigned freeLQEntries;
	unsigned freeSQEntries;
	unsigned dispatchedToLQ;
	unsigned dispatchedToSQ;

	unsigned iqCount;
	unsigned ldstqCount;

	unsigned dispatched;
	bool usedIQ;
	bool usedLSQ;
	};

	IewComm iewInfo[MaxThreads];

	struct CommitComm
	{
	/////////////////////////////////////////////////////////////////////
	// This code has been re-structured for better packing of variables
	// instead of by stage which is the more logical way to arrange the
	// data.
	// F = Fetch
	// D = Decode
	// I = IEW
	// R = Rename
	// As such each member is annotated with who consumes it
	// e.g. bool variable name // *F,R for Fetch and Rename
	/////////////////////////////////////////////////////////////////////

	/// The pc of the next instruction to execute. This is the next
	/// instruction for a branch mispredict, but the same instruction for
	/// order violation and the like
	std::unique_ptr<PCStateBase> pc; // *F

	/// Provide fetch the instruction that mispredicted, if this
	/// pointer is not-null a misprediction occured
	DynInstPtr mispredictInst; // *F

	/// Instruction that caused the a non-mispredict squash
	DynInstPtr squashInst; // *F

	/// Hack for now to send back a strictly ordered access to the
	/// IEW stage.
	DynInstPtr strictlyOrderedLoad; // *I

	/// Communication specifically to the IQ to tell the IQ that it can
	/// schedule a non-speculative instruction.
	InstSeqNum nonSpecSeqNum; // *I

	/// Represents the instruction that has either been retired or
	/// squashed. Similar to having a single bus that broadcasts the
	/// retired or squashed sequence number.
	InstSeqNum doneSeqNum; // *F, I

	/// Tell Rename how many free entries it has in the ROB
	unsigned freeROBEntries; // *R

	bool squash; // *F, D, R, I
	bool robSquashing; // *F, D, R, I

	/// Rename should re-read number of free rob entries
	bool usedROB; // *R

	/// Notify Rename that the ROB is empty
	bool emptyROB; // *R

	/// Was the branch taken or not
	bool branchTaken; // *F
	/// If an interrupt is pending and fetch should stall
	bool interruptPending; // *F
	/// If the interrupt ended up being cleared before being handled
	bool clearInterrupt; // *F

	/// Hack for now to send back an strictly ordered access to
	/// the IEW stage.
	bool strictlyOrdered; // *I

	};

	CommitComm commitInfo[MaxThreads];

	bool decodeBlock[MaxThreads];
	bool decodeUnblock[MaxThreads];
	bool renameBlock[MaxThreads];
	bool renameUnblock[MaxThreads];
	bool iewBlock[MaxThreads];
	bool iewUnblock[MaxThreads];
	};

	} // namespace o3
	} // namespace gem5

	#endif //__CPU_O3_COMM_HH__