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#ifndef __FREE_LIST_HH__
#define __FREE_LIST_HH__
#include <iostream>
#include <queue>
#include "arch/alpha/isa_traits.hh"
#include "cpu/beta_cpu/comm.hh"
#include "base/trace.hh"
using namespace std;
// Question: Do I even need the number of logical registers?
// How to avoid freeing registers instantly? Same with ROB entries.
/**
* 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 SimpleFreeList
{
public:
private:
/** The list of free integer registers. */
queue<PhysRegIndex> freeIntRegs;
/** The list of free floating point registers. */
queue<PhysRegIndex> freeFloatRegs;
/** Number of logical integer registers. */
int numLogicalIntRegs;
/** Number of physical integer registers. */
int numPhysicalIntRegs;
/** Number of logical floating point registers. */
int numLogicalFloatRegs;
/** Number of physical floating point registers. */
int numPhysicalFloatRegs;
/** Total number of physical registers. */
int numPhysicalRegs;
public:
SimpleFreeList(unsigned _numLogicalIntRegs,
unsigned _numPhysicalIntRegs,
unsigned _numLogicalFloatRegs,
unsigned _numPhysicalFloatRegs);
PhysRegIndex getIntReg();
PhysRegIndex getFloatReg();
void addReg(PhysRegIndex freed_reg);
void addIntReg(PhysRegIndex freed_reg);
void addFloatReg(PhysRegIndex freed_reg);
bool hasFreeIntRegs()
{ return !freeIntRegs.empty(); }
bool hasFreeFloatRegs()
{ return !freeFloatRegs.empty(); }
int numFreeIntRegs()
{ return freeIntRegs.size(); }
int numFreeFloatRegs()
{ return freeFloatRegs.size(); }
};
inline PhysRegIndex
SimpleFreeList::getIntReg()
{
DPRINTF(Rename, "FreeList: Trying to get free integer register.\n");
if (freeIntRegs.empty()) {
panic("No free integer registers!");
}
PhysRegIndex free_reg = freeIntRegs.front();
freeIntRegs.pop();
return(free_reg);
}
inline PhysRegIndex
SimpleFreeList::getFloatReg()
{
DPRINTF(Rename, "FreeList: Trying to get free float register.\n");
if (freeFloatRegs.empty()) {
panic("No free integer registers!");
}
PhysRegIndex free_reg = freeFloatRegs.front();
freeFloatRegs.pop();
return(free_reg);
}
inline void
SimpleFreeList::addReg(PhysRegIndex freed_reg)
{
DPRINTF(Rename, "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 (freed_reg < numPhysicalIntRegs) {
freeIntRegs.push(freed_reg);
} else if (freed_reg < numPhysicalRegs) {
freeFloatRegs.push(freed_reg);
}
}
inline void
SimpleFreeList::addIntReg(PhysRegIndex freed_reg)
{
DPRINTF(Rename, "Freelist: Freeing int 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.
freeIntRegs.push(freed_reg);
}
inline void
SimpleFreeList::addFloatReg(PhysRegIndex freed_reg)
{
DPRINTF(Rename, "Freelist: Freeing float 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.
freeFloatRegs.push(freed_reg);
}
#endif // __FREE_LIST_HH__
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