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/*
* scoreboard.cc
*
* Created on: Aug 10, 2010
* Author: inder
*/
#include "scoreboard.h"
#include "shader.h"
#include "../cuda-sim/ptx_sim.h"
//Constructor
Scoreboard::Scoreboard( unsigned sid, unsigned n_warps )
{
m_sid = sid;
//Initialize size of table
reg_table.resize(n_warps);
}
// Print scoreboard contents
void Scoreboard::printContents()
{
printf("scoreboard contents (sid=%d): \n", m_sid);
for(unsigned i=0; i<reg_table.size(); i++) {
if(reg_table[i].size() == 0 ) continue;
printf(" wid = %d: ", i);
std::set<int>::iterator it;
for ( it=reg_table[i].begin() ; it != reg_table[i].end(); it++ )
printf("%d ", *it);
printf("\n");
}
}
// Mark register as write-pending
void Scoreboard::reserveRegister(unsigned wid, unsigned regnum)
{
if( !(reg_table[wid].find(regnum) == reg_table[wid].end()) ){
printf("Error: trying to reserve an already reserved register (sid=%d, wid=%d, regnum=%d).", m_sid, wid, regnum);
assert(reg_table[wid].find(regnum) == reg_table[wid].end());
}
reg_table[wid].insert(regnum);
}
// Unmark register as write-pending
void Scoreboard::releaseRegister(unsigned wid, unsigned regnum)
{
if( !(reg_table[wid].find(regnum) != reg_table[wid].end()) ) {
printf("Error: trying to release an unreserved register (sid=%d, wid=%d, regnum=%d).", m_sid, wid, regnum);
assert(reg_table[wid].find(regnum) != reg_table[wid].end());
}
reg_table[wid].erase(regnum);
}
// Reserve registers for an instruction
void Scoreboard::reserveRegisters(unsigned wid, const class inst_t* inst)
{
// Reserve registers
if(inst->out[0] > 0) reserveRegister(wid, inst->out[0]);
if(inst->out[1] > 0) reserveRegister(wid, inst->out[1]);
if(inst->out[2] > 0) reserveRegister(wid, inst->out[2]);
if(inst->out[3] > 0) reserveRegister(wid, inst->out[3]);
}
// Release registers for an instruction
void Scoreboard::releaseRegisters(unsigned wid, const class inst_t *inst)
{
if(inst->out[0] > 0) releaseRegister(wid, inst->out[0]);
if(inst->out[1] > 0) releaseRegister(wid, inst->out[1]);
if(inst->out[2] > 0) releaseRegister(wid, inst->out[2]);
if(inst->out[3] > 0) releaseRegister(wid, inst->out[3]);
}
/**
* Checks to see if registers used by an instruction are reserved in the scoreboard
*
* @return
* true if WAW or RAW hazard (no WAR since in-order issue)
**/
bool Scoreboard::checkCollision( unsigned wid, const class inst_t *inst )
{
// Get list of all input and output registers
std::set<int> inst_regs;
if(inst->out[0] > 0) inst_regs.insert(inst->out[0]);
if(inst->out[1] > 0) inst_regs.insert(inst->out[1]);
if(inst->out[2] > 0) inst_regs.insert(inst->out[2]);
if(inst->out[3] > 0) inst_regs.insert(inst->out[3]);
if(inst->in[0] > 0) inst_regs.insert(inst->in[0]);
if(inst->in[1] > 0) inst_regs.insert(inst->in[1]);
if(inst->in[2] > 0) inst_regs.insert(inst->in[2]);
if(inst->in[3] > 0) inst_regs.insert(inst->in[3]);
if(inst->pred > 0) inst_regs.insert(inst->pred);
if(inst->ar1 > 0) inst_regs.insert(inst->ar1);
if(inst->ar2 > 0) inst_regs.insert(inst->ar2);
// Check for collision, get the intersection of reserved registers and instruction registers
std::set<int>::iterator it2;
for ( it2=inst_regs.begin() ; it2 != inst_regs.end(); it2++ )
if(reg_table[wid].find(*it2) != reg_table[wid].end()) {
return true;
}
return false;
}
bool Scoreboard::pendingWrites(unsigned wid) const
{
return !reg_table[wid].empty();
}
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