211 lines
7.7 KiB
C++
211 lines
7.7 KiB
C++
/*
|
|
* Copyright (c) 2004-2005 The Regents of The University of Michigan
|
|
* Copyright (c) 2013 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: 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: Kevin Lim
|
|
*/
|
|
|
|
#ifndef __CPU_O3_FREE_LIST_HH__
|
|
#define __CPU_O3_FREE_LIST_HH__
|
|
|
|
#include <iostream>
|
|
#include <queue>
|
|
|
|
#include "base/misc.hh"
|
|
#include "base/trace.hh"
|
|
#include "cpu/o3/comm.hh"
|
|
#include "cpu/o3/regfile.hh"
|
|
#include "debug/FreeList.hh"
|
|
|
|
/**
|
|
* Free list for a single class of registers (e.g., integer
|
|
* or floating point). Because the register class is implicitly
|
|
* determined by the rename map instance being accessed, all
|
|
* architectural register index parameters and values in this class
|
|
* are relative (e.g., %fp2 is just index 2).
|
|
*/
|
|
class SimpleFreeList
|
|
{
|
|
private:
|
|
|
|
/** The actual free list */
|
|
std::queue<PhysRegIndex> freeRegs;
|
|
|
|
public:
|
|
|
|
SimpleFreeList() {};
|
|
|
|
/** Add a physical register to the free list */
|
|
void addReg(PhysRegIndex reg) { freeRegs.push(reg); }
|
|
|
|
/** Get the next available register from the free list */
|
|
PhysRegIndex getReg()
|
|
{
|
|
assert(!freeRegs.empty());
|
|
PhysRegIndex free_reg = freeRegs.front();
|
|
freeRegs.pop();
|
|
return free_reg;
|
|
}
|
|
|
|
/** Return the number of free registers on the list. */
|
|
unsigned numFreeRegs() const { return freeRegs.size(); }
|
|
|
|
/** True iff there are free registers on the list. */
|
|
bool hasFreeRegs() const { return !freeRegs.empty(); }
|
|
};
|
|
|
|
|
|
/**
|
|
* FreeList class that simply holds the list of free integer and floating
|
|
* point registers. Can request for a free register of either type, and
|
|
* also send back free registers of either type. This is a very simple
|
|
* class, but it should be sufficient for most implementations. Like all
|
|
* other classes, it assumes that the indices for the floating point
|
|
* registers starts after the integer registers end. Hence the variable
|
|
* numPhysicalIntRegs is logically equivalent to the baseFP dependency.
|
|
* Note that while this most likely should be called FreeList, the name
|
|
* "FreeList" is used in a typedef within the CPU Policy, and therefore no
|
|
* class can be named simply "FreeList".
|
|
* @todo: Give a better name to the base FP dependency.
|
|
*/
|
|
class UnifiedFreeList
|
|
{
|
|
private:
|
|
|
|
/** The object name, for DPRINTF. We have to declare this
|
|
* explicitly because Scoreboard is not a SimObject. */
|
|
const std::string _name;
|
|
|
|
/** The list of free integer registers. */
|
|
SimpleFreeList intList;
|
|
|
|
/** The list of free floating point registers. */
|
|
SimpleFreeList floatList;
|
|
|
|
/** The list of free condition-code registers. */
|
|
SimpleFreeList ccList;
|
|
|
|
/**
|
|
* The register file object is used only to distinguish integer
|
|
* from floating-point physical register indices.
|
|
*/
|
|
PhysRegFile *regFile;
|
|
|
|
/*
|
|
* We give UnifiedRenameMap internal access so it can get at the
|
|
* internal per-class free lists and associate those with its
|
|
* per-class rename maps. See UnifiedRenameMap::init().
|
|
*/
|
|
friend class UnifiedRenameMap;
|
|
|
|
public:
|
|
/** Constructs a free list.
|
|
* @param _numPhysicalIntRegs Number of physical integer registers.
|
|
* @param reservedIntRegs Number of integer registers already
|
|
* used by initial mappings.
|
|
* @param _numPhysicalFloatRegs Number of physical fp registers.
|
|
* @param reservedFloatRegs Number of fp registers already
|
|
* used by initial mappings.
|
|
*/
|
|
UnifiedFreeList(const std::string &_my_name, PhysRegFile *_regFile);
|
|
|
|
/** Gives the name of the freelist. */
|
|
std::string name() const { return _name; };
|
|
|
|
/** Returns a pointer to the condition-code free list */
|
|
SimpleFreeList *getCCList() { return &ccList; }
|
|
|
|
/** Gets a free integer register. */
|
|
PhysRegIndex getIntReg() { return intList.getReg(); }
|
|
|
|
/** Gets a free fp register. */
|
|
PhysRegIndex getFloatReg() { return floatList.getReg(); }
|
|
|
|
/** Gets a free cc register. */
|
|
PhysRegIndex getCCReg() { return ccList.getReg(); }
|
|
|
|
/** Adds a register back to the free list. */
|
|
void addReg(PhysRegIndex freed_reg);
|
|
|
|
/** Adds an integer register back to the free list. */
|
|
void addIntReg(PhysRegIndex freed_reg) { intList.addReg(freed_reg); }
|
|
|
|
/** Adds a fp register back to the free list. */
|
|
void addFloatReg(PhysRegIndex freed_reg) { floatList.addReg(freed_reg); }
|
|
|
|
/** Adds a cc register back to the free list. */
|
|
void addCCReg(PhysRegIndex freed_reg) { ccList.addReg(freed_reg); }
|
|
|
|
/** Checks if there are any free integer registers. */
|
|
bool hasFreeIntRegs() const { return intList.hasFreeRegs(); }
|
|
|
|
/** Checks if there are any free fp registers. */
|
|
bool hasFreeFloatRegs() const { return floatList.hasFreeRegs(); }
|
|
|
|
/** Checks if there are any free cc registers. */
|
|
bool hasFreeCCRegs() const { return ccList.hasFreeRegs(); }
|
|
|
|
/** Returns the number of free integer registers. */
|
|
unsigned numFreeIntRegs() const { return intList.numFreeRegs(); }
|
|
|
|
/** Returns the number of free fp registers. */
|
|
unsigned numFreeFloatRegs() const { return floatList.numFreeRegs(); }
|
|
|
|
/** Returns the number of free cc registers. */
|
|
unsigned numFreeCCRegs() const { return ccList.numFreeRegs(); }
|
|
};
|
|
|
|
inline void
|
|
UnifiedFreeList::addReg(PhysRegIndex freed_reg)
|
|
{
|
|
DPRINTF(FreeList,"Freeing register %i.\n", freed_reg);
|
|
//Might want to add in a check for whether or not this register is
|
|
//already in there. A bit vector or something similar would be useful.
|
|
if (regFile->isIntPhysReg(freed_reg)) {
|
|
intList.addReg(freed_reg);
|
|
} else if (regFile->isFloatPhysReg(freed_reg)) {
|
|
floatList.addReg(freed_reg);
|
|
} else {
|
|
assert(regFile->isCCPhysReg(freed_reg));
|
|
ccList.addReg(freed_reg);
|
|
}
|
|
|
|
// These assert conditions ensure that the number of free
|
|
// registers are not more than the # of total Physical Registers.
|
|
// If this were false, it would mean that registers
|
|
// have been freed twice, overflowing the free register
|
|
// pool and potentially crashing SMT workloads.
|
|
// ----
|
|
// Comment out for now so as to not potentially break
|
|
// CMP and single-threaded workloads
|
|
// ----
|
|
// assert(freeIntRegs.size() <= numPhysicalIntRegs);
|
|
// assert(freeFloatRegs.size() <= numPhysicalFloatRegs);
|
|
}
|
|
|
|
|
|
#endif // __CPU_O3_FREE_LIST_HH__
|