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Diffstat (limited to 'src/cpu/o3/bpred_unit_impl.hh')
-rw-r--r--src/cpu/o3/bpred_unit_impl.hh103
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++;
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-13 13:57:25 +0000