diff options
Diffstat (limited to 'src/cpu/o3/bpred_unit_impl.hh')
-rw-r--r-- | src/cpu/o3/bpred_unit_impl.hh | 103 |
1 files changed, 50 insertions, 53 deletions
diff --git a/src/cpu/o3/bpred_unit_impl.hh b/src/cpu/o3/bpred_unit_impl.hh index ed3471761..14d47df9f 100644 --- a/src/cpu/o3/bpred_unit_impl.hh +++ b/src/cpu/o3/bpred_unit_impl.hh @@ -31,6 +31,7 @@ #include <algorithm> #include "arch/types.hh" +#include "arch/utility.hh" #include "arch/isa_traits.hh" #include "base/trace.hh" #include "base/traceflags.hh" @@ -144,17 +145,15 @@ BPredUnit<Impl>::takeOverFrom() template <class Impl> bool -BPredUnit<Impl>::predict(DynInstPtr &inst, Addr &PC, ThreadID tid) +BPredUnit<Impl>::predict(DynInstPtr &inst, TheISA::PCState &pc, ThreadID tid) { // See if branch predictor predicts taken. // If so, get its target addr either from the BTB or the RAS. // Save off record of branch stuff so the RAS can be fixed // up once it's done. - using TheISA::MachInst; - bool pred_taken = false; - Addr target = PC; + TheISA::PCState target = pc; ++lookups; @@ -168,19 +167,19 @@ BPredUnit<Impl>::predict(DynInstPtr &inst, Addr &PC, ThreadID tid) } else { ++condPredicted; - pred_taken = BPLookup(PC, bp_history); + pred_taken = BPLookup(pc.instAddr(), bp_history); DPRINTF(Fetch, "BranchPred: [tid:%i]: Branch predictor predicted %i " - "for PC %#x\n", - tid, pred_taken, inst->readPC()); + "for PC %s\n", + tid, pred_taken, inst->pcState()); } DPRINTF(Fetch, "BranchPred: [tid:%i]: [sn:%i] Creating prediction history " - "for PC %#x\n", - tid, inst->seqNum, inst->readPC()); + "for PC %s\n", + tid, inst->seqNum, inst->pcState()); - PredictorHistory predict_record(inst->seqNum, PC, pred_taken, - bp_history, tid); + PredictorHistory predict_record(inst->seqNum, pc.instAddr(), + pred_taken, bp_history, tid); // Now lookup in the BTB or RAS. if (pred_taken) { @@ -189,60 +188,58 @@ BPredUnit<Impl>::predict(DynInstPtr &inst, Addr &PC, ThreadID tid) // If it's a function return call, then look up the address // in the RAS. - target = RAS[tid].top(); + TheISA::PCState rasTop = RAS[tid].top(); + target = TheISA::buildRetPC(pc, rasTop); // Record the top entry of the RAS, and its index. predict_record.usedRAS = true; predict_record.RASIndex = RAS[tid].topIdx(); - predict_record.RASTarget = target; + predict_record.RASTarget = rasTop; assert(predict_record.RASIndex < 16); RAS[tid].pop(); - DPRINTF(Fetch, "BranchPred: [tid:%i]: Instruction %#x is a return, " - "RAS predicted target: %#x, RAS index: %i.\n", - tid, inst->readPC(), target, predict_record.RASIndex); + DPRINTF(Fetch, "BranchPred: [tid:%i]: Instruction %s is a return, " + "RAS predicted target: %s, RAS index: %i.\n", + tid, inst->pcState(), target, predict_record.RASIndex); } else { ++BTBLookups; if (inst->isCall()) { -#if ISA_HAS_DELAY_SLOT - Addr ras_pc = PC + (2 * sizeof(MachInst)); // Next Next PC -#else - Addr ras_pc = PC + sizeof(MachInst); // Next PC -#endif - RAS[tid].push(ras_pc); + RAS[tid].push(pc); // Record that it was a call so that the top RAS entry can // be popped off if the speculation is incorrect. predict_record.wasCall = true; - DPRINTF(Fetch, "BranchPred: [tid:%i]: Instruction %#x was a call" - ", adding %#x to the RAS index: %i.\n", - tid, inst->readPC(), ras_pc, RAS[tid].topIdx()); + DPRINTF(Fetch, "BranchPred: [tid:%i]: Instruction %s was a " + "call, adding %s to the RAS index: %i.\n", + tid, inst->pcState(), pc, RAS[tid].topIdx()); } - if (BTB.valid(PC, tid)) { + if (BTB.valid(pc.instAddr(), tid)) { ++BTBHits; // If it's not a return, use the BTB to get the target addr. - target = BTB.lookup(PC, tid); + target = BTB.lookup(pc.instAddr(), tid); - DPRINTF(Fetch, "BranchPred: [tid:%i]: Instruction %#x predicted" - " target is %#x.\n", - tid, inst->readPC(), target); + DPRINTF(Fetch, "BranchPred: [tid:%i]: Instruction %s predicted" + " target is %s.\n", tid, inst->pcState(), target); } else { DPRINTF(Fetch, "BranchPred: [tid:%i]: BTB doesn't have a " "valid entry.\n",tid); pred_taken = false; + TheISA::advancePC(target, inst->staticInst); } } + } else { + TheISA::advancePC(target, inst->staticInst); } - PC = target; + pc = target; predHist[tid].push_front(predict_record); @@ -262,7 +259,7 @@ BPredUnit<Impl>::update(const InstSeqNum &done_sn, ThreadID tid) while (!predHist[tid].empty() && predHist[tid].back().seqNum <= done_sn) { // Update the branch predictor with the correct results. - BPUpdate(predHist[tid].back().PC, + BPUpdate(predHist[tid].back().pc, predHist[tid].back().predTaken, predHist[tid].back().bpHistory); @@ -280,10 +277,8 @@ BPredUnit<Impl>::squash(const InstSeqNum &squashed_sn, ThreadID tid) pred_hist.front().seqNum > squashed_sn) { if (pred_hist.front().usedRAS) { DPRINTF(Fetch, "BranchPred: [tid:%i]: Restoring top of RAS to: %i," - " target: %#x.\n", - tid, - pred_hist.front().RASIndex, - pred_hist.front().RASTarget); + " target: %s.\n", tid, + pred_hist.front().RASIndex, pred_hist.front().RASTarget); RAS[tid].restore(pred_hist.front().RASIndex, pred_hist.front().RASTarget); @@ -298,11 +293,13 @@ BPredUnit<Impl>::squash(const InstSeqNum &squashed_sn, ThreadID tid) BPSquash(pred_hist.front().bpHistory); DPRINTF(Fetch, "BranchPred: [tid:%i]: Removing history for [sn:%i] " - "PC %#x.\n", tid, pred_hist.front().seqNum, pred_hist.front().PC); + "PC %s.\n", tid, pred_hist.front().seqNum, + pred_hist.front().pc); pred_hist.pop_front(); - DPRINTF(Fetch, "[tid:%i]: predHist.size(): %i\n", tid, predHist[tid].size()); + DPRINTF(Fetch, "[tid:%i]: predHist.size(): %i\n", + tid, predHist[tid].size()); } } @@ -310,7 +307,7 @@ BPredUnit<Impl>::squash(const InstSeqNum &squashed_sn, ThreadID tid) template <class Impl> void BPredUnit<Impl>::squash(const InstSeqNum &squashed_sn, - const Addr &corr_target, + const TheISA::PCState &corrTarget, bool actually_taken, ThreadID tid) { @@ -330,8 +327,8 @@ BPredUnit<Impl>::squash(const InstSeqNum &squashed_sn, ++condIncorrect; DPRINTF(Fetch, "BranchPred: [tid:%i]: Squashing from sequence number %i, " - "setting target to %#x.\n", - tid, squashed_sn, corr_target); + "setting target to %s.\n", + tid, squashed_sn, corrTarget); // Squash All Branches AFTER this mispredicted branch squash(squashed_sn, tid); @@ -358,13 +355,13 @@ BPredUnit<Impl>::squash(const InstSeqNum &squashed_sn, ++RASIncorrect; } - BPUpdate((*hist_it).PC, actually_taken, + BPUpdate((*hist_it).pc, actually_taken, pred_hist.front().bpHistory); - BTB.update((*hist_it).PC, corr_target, tid); + BTB.update((*hist_it).pc, corrTarget, tid); DPRINTF(Fetch, "BranchPred: [tid:%i]: Removing history for [sn:%i] " - "PC %#x.\n", tid, (*hist_it).seqNum, (*hist_it).PC); + "PC %s.\n", tid, (*hist_it).seqNum, (*hist_it).pc); pred_hist.erase(hist_it); @@ -397,12 +394,12 @@ BPredUnit<Impl>::BPSquash(void *bp_history) template <class Impl> bool -BPredUnit<Impl>::BPLookup(Addr &inst_PC, void * &bp_history) +BPredUnit<Impl>::BPLookup(Addr instPC, void * &bp_history) { if (predictor == Local) { - return localBP->lookup(inst_PC, bp_history); + return localBP->lookup(instPC, bp_history); } else if (predictor == Tournament) { - return tournamentBP->lookup(inst_PC, bp_history); + return tournamentBP->lookup(instPC, bp_history); } else { panic("Predictor type is unexpected value!"); } @@ -410,12 +407,12 @@ BPredUnit<Impl>::BPLookup(Addr &inst_PC, void * &bp_history) template <class Impl> void -BPredUnit<Impl>::BPUpdate(Addr &inst_PC, bool taken, void *bp_history) +BPredUnit<Impl>::BPUpdate(Addr instPC, bool taken, void *bp_history) { if (predictor == Local) { - localBP->update(inst_PC, taken, bp_history); + localBP->update(instPC, taken, bp_history); } else if (predictor == Tournament) { - tournamentBP->update(inst_PC, taken, bp_history); + tournamentBP->update(instPC, taken, bp_history); } else { panic("Predictor type is unexpected value!"); } @@ -436,9 +433,9 @@ BPredUnit<Impl>::dump() while (pred_hist_it != predHist[i].end()) { cprintf("[sn:%lli], PC:%#x, tid:%i, predTaken:%i, " "bpHistory:%#x\n", - (*pred_hist_it).seqNum, (*pred_hist_it).PC, - (*pred_hist_it).tid, (*pred_hist_it).predTaken, - (*pred_hist_it).bpHistory); + pred_hist_it->seqNum, pred_hist_it->pc, + pred_hist_it->tid, pred_hist_it->predTaken, + pred_hist_it->bpHistory); pred_hist_it++; } |