diff options
Diffstat (limited to 'src/cpu/pred/ltage.cc')
| -rw-r--r-- | src/cpu/pred/ltage.cc | 18 |
1 files changed, 10 insertions, 8 deletions
diff --git a/src/cpu/pred/ltage.cc b/src/cpu/pred/ltage.cc index 85ae2b304..b049d4fde 100644 --- a/src/cpu/pred/ltage.cc +++ b/src/cpu/pred/ltage.cc @@ -55,6 +55,7 @@ LTAGE::LTAGE(const LTAGEParams *params) logSizeLoopPred(params->logSizeLoopPred), nHistoryTables(params->nHistoryTables), tagTableCounterBits(params->tagTableCounterBits), + tagTableUBits(params->tagTableUBits), histBufferSize(params->histBufferSize), minHist(params->minHist), maxHist(params->maxHist), @@ -68,6 +69,11 @@ LTAGE::LTAGE(const LTAGEParams *params) loopNumIterMask((1 << loopTableIterBits) - 1), threadHistory(params->numThreads) { + // Current method for periodically resetting the u counter bits only + // works for 1 or 2 bits + // Also make sure that it is not 0 + assert(tagTableUBits <= 2 && (tagTableUBits > 0)); + // we use uint16_t type for these vales, so they cannot be more than // 16 bits assert(loopTableTagBits <= 16); @@ -576,7 +582,7 @@ LTAGE::update(ThreadID tid, Addr branch_pc, bool taken, void* bp_history, if (alloc) { // is there some "unuseful" entry to allocate - int8_t min = 1; + uint8_t min = 1; for (int i = nHistoryTables; i > bi->hitBank; i--) { if (gtable[i][bi->tableIndices[i]].u < min) { min = gtable[i][bi->tableIndices[i]].u; @@ -605,7 +611,6 @@ LTAGE::update(ThreadID tid, Addr branch_pc, bool taken, void* bp_history, if ((gtable[i][bi->tableIndices[i]].u == 0)) { gtable[i][bi->tableIndices[i]].tag = bi->tableTags[i]; gtable[i][bi->tableIndices[i]].ctr = (taken) ? 0 : -1; - gtable[i][bi->tableIndices[i]].u = 0; //? break; } } @@ -643,12 +648,9 @@ LTAGE::update(ThreadID tid, Addr branch_pc, bool taken, void* bp_history, } // update the u counter - if (longest_match_pred != bi->altTaken) { - if (longest_match_pred == taken) { - if (gtable[bi->hitBank][bi->hitBankIndex].u < 1) { - gtable[bi->hitBank][bi->hitBankIndex].u++; - } - } + if (bi->tagePred != bi->altTaken) { + unsignedCtrUpdate(gtable[bi->hitBank][bi->hitBankIndex].u, + bi->tagePred == taken, tagTableUBits); } } else { baseUpdate(pc, taken, bi); |