void bpred_gshare_update(bpred *b, unsigned int pc, int pred_dir,
int resolve_dir) {
//update pht
int pht_index = pc ^ b->ghr;
pht_index = pht_index % (b->pht_entries);
int pht_ctr = b->pht[pht_index];
int new_pht_ctr;
int branchPredMask = 1 << b->hist_len;
//update ghr
//bit shift ghr
b->ghr = b->ghr << 1;
//or with actually taken value (resolve_dir) to update ghr
b->ghr = b->ghr | resolve_dir;
//mask to keep correct value
b->ghr = b->ghr % branchPredMask;
if (resolve_dir == 1) {
new_pht_ctr = BPRED_SAT_INC(pht_ctr, BPRED_PHT_CTR_MAX);
} else {
new_pht_ctr = BPRED_SAT_DEC(pht_ctr);
}
b->pht[pht_index] = new_pht_ctr;
//update counters
if (pred_dir == resolve_dir) {
b->okpred = b->okpred + 1;
} else {
b->mispred = b->mispred + 1;
}
}
void bpred_gshare_update(bpred *b, unsigned int pc,
int pred_dir, int resolve_dir)
{
int pht_index = (pc ^ b->ghr) % (b->pht_entries);
int pht_ctr = b->pht[pht_index];
b->ghr = (((b->ghr)<<1) | resolve_dir);
b->pht[pht_index] = resolve_dir ? BPRED_SAT_INC(pht_ctr,3) : BPRED_SAT_DEC(pht_ctr);
}
void bpred_bimodal_update(bpred *b, unsigned int pc, int pred_dir, int resolve_dir) {
int pht_index = pc % (b->pht_entries);
int pht_ctr = b->pht[pht_index];
int new_pht_ctr;
if(resolve_dir==1)
new_pht_ctr = BPRED_SAT_INC(pht_ctr, BPRED_PHT_CTR_MAX);
else
new_pht_ctr = BPRED_SAT_DEC(pht_ctr);
b->pht[pht_index] = new_pht_ctr;
}
void bpred_gshare_update(bpred *b, unsigned int pc, int pred_dir, int resolve_dir, int thread_id){
int pht_index = (pc^b->ghr[thread_id]) % (b->pht_entries);
int pht_ctr = b->pht[pht_index];
int new_pht_ctr;
if(resolve_dir==1) {
new_pht_ctr = BPRED_SAT_INC(pht_ctr, BPRED_PHT_CTR_MAX);
b->ghr[thread_id] = (b->ghr[thread_id]<<1) | 0x00000001;
}
else {
new_pht_ctr = BPRED_SAT_DEC(pht_ctr);
b->ghr[thread_id] = (b->ghr[thread_id]<<1);
}
b->pht[pht_index] = new_pht_ctr;
}
