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mi-sched: Precompute a PressureDiff for each instruction, adjust for liveness later.

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Created SUPressureDiffs array to hold the per node PDiff computed during DAG building.

Added a getUpwardPressureDelta API that will soon replace the old
one. Compute PressureDelta here from the precomputed PressureDiffs.

Updating for liveness will come next.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189640 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Andrew Trick
2013-08-30 03:49:48 +00:00
parent e206efd39b
commit 4c60b8a78d
11 changed files with 391 additions and 101 deletions
Download Patch File Download Diff File Expand all files Collapse all files
lib/CodeGen/MachineScheduler.cpp
+51 -27
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@@ -505,13 +505,13 @@ void ScheduleDAGMI::initRegPressure() {
DEBUG(dbgs() << TRI->getRegPressureSetName(i)
<< " Limit " << Limit
<< " Actual " << RegionPressure[i] << "\n");
RegionCriticalPSets.push_back(PressureElement(i, 0));
RegionCriticalPSets.push_back(PressureChange(i));
}
}
DEBUG(dbgs() << "Excess PSets: ";
for (unsigned i = 0, e = RegionCriticalPSets.size(); i != e; ++i)
dbgs() << TRI->getRegPressureSetName(
RegionCriticalPSets[i].PSetID) << " ";
RegionCriticalPSets[i].getPSet()) << " ";
dbgs() << "\n");
}
@@ -520,10 +520,10 @@ void ScheduleDAGMI::initRegPressure() {
void ScheduleDAGMI::
updateScheduledPressure(const std::vector<unsigned> &NewMaxPressure) {
for (unsigned i = 0, e = RegionCriticalPSets.size(); i < e; ++i) {
unsigned ID = RegionCriticalPSets[i].PSetID;
int &MaxUnits = RegionCriticalPSets[i].UnitIncrease;
if ((int)NewMaxPressure[ID] > MaxUnits)
MaxUnits = NewMaxPressure[ID];
unsigned ID = RegionCriticalPSets[i].getPSet();
if ((int)NewMaxPressure[ID] > RegionCriticalPSets[i].getUnitInc()
&& NewMaxPressure[ID] <= INT16_MAX)
RegionCriticalPSets[i].setUnitInc(NewMaxPressure[ID]);
}
DEBUG(
for (unsigned i = 0, e = NewMaxPressure.size(); i < e; ++i) {
@@ -599,7 +599,7 @@ void ScheduleDAGMI::buildDAGWithRegPressure() {
RPTracker.recede();
// Build the DAG, and compute current register pressure.
buildSchedGraph(AA, &RPTracker);
buildSchedGraph(AA, &RPTracker, &SUPressureDiffs);
// Initialize top/bottom trackers after computing region pressure.
initRegPressure();
@@ -2177,26 +2177,28 @@ static bool tryGreater(int TryVal, int CandVal,
return false;
}
static bool tryPressure(const PressureElement &TryP,
const PressureElement &CandP,
static bool tryPressure(const PressureChange &TryP,
const PressureChange &CandP,
ConvergingScheduler::SchedCandidate &TryCand,
ConvergingScheduler::SchedCandidate &Cand,
ConvergingScheduler::CandReason Reason) {
// If both candidates affect the same set, go with the smallest increase.
if (TryP.PSetID == CandP.PSetID) {
return tryLess(TryP.UnitIncrease, CandP.UnitIncrease, TryCand, Cand,
Reason);
}
// If one candidate decreases and the other increases, go with it.
if (tryLess(TryP.UnitIncrease < 0, CandP.UnitIncrease < 0, TryCand, Cand,
Reason)) {
return true;
if (TryP.isValid() && CandP.isValid()) {
// If both candidates affect the same set, go with the smallest increase.
if (TryP.getPSet() == CandP.getPSet()) {
return tryLess(TryP.getUnitInc(), CandP.getUnitInc(), TryCand, Cand,
Reason);
}
// If one candidate decreases and the other increases, go with it.
if (tryLess(TryP.getUnitInc() < 0, CandP.getUnitInc() < 0, TryCand, Cand,
Reason)) {
return true;
}
}
// If TryP has lower Rank, it has a higher priority.
int TryRank = TryP.PSetRank();
int CandRank = CandP.PSetRank();
int TryRank = TryP.getRank();
int CandRank = CandP.getRank();
// If the candidates are decreasing pressure, reverse priority.
if (TryP.UnitIncrease < 0)
if (TryP.getUnitInc() < 0)
std::swap(TryRank, CandRank);
return tryGreater(TryRank, CandRank, TryCand, Cand, Reason);
}
@@ -2277,9 +2279,31 @@ void ConvergingScheduler::tryCandidate(SchedCandidate &Cand,
RegPressureTracker &TempTracker) {
// Always initialize TryCand's RPDelta.
TempTracker.getMaxPressureDelta(TryCand.SU->getInstr(), TryCand.RPDelta,
DAG->getRegionCriticalPSets(),
DAG->getRegPressure().MaxSetPressure);
if (Zone.isTop()) {
TempTracker.getMaxDownwardPressureDelta(
TryCand.SU->getInstr(),
TryCand.RPDelta,
DAG->getRegionCriticalPSets(),
DAG->getRegPressure().MaxSetPressure);
}
else {
if (VerifyScheduling) {
TempTracker.getMaxUpwardPressureDelta(
TryCand.SU->getInstr(),
&DAG->getPressureDiff(TryCand.SU),
TryCand.RPDelta,
DAG->getRegionCriticalPSets(),
DAG->getRegPressure().MaxSetPressure);
}
else {
RPTracker.getUpwardPressureDelta(
TryCand.SU->getInstr(),
DAG->getPressureDiff(TryCand.SU),
TryCand.RPDelta,
DAG->getRegionCriticalPSets(),
DAG->getRegPressure().MaxSetPressure);
}
}
// Initialize the candidate if needed.
if (!Cand.isValid()) {
@@ -2385,7 +2409,7 @@ const char *ConvergingScheduler::getReasonStr(
}
void ConvergingScheduler::traceCandidate(const SchedCandidate &Cand) {
PressureElement P;
PressureChange P;
unsigned ResIdx = 0;
unsigned Latency = 0;
switch (Cand.Reason) {
@@ -2421,8 +2445,8 @@ void ConvergingScheduler::traceCandidate(const SchedCandidate &Cand) {
}
dbgs() << " SU(" << Cand.SU->NodeNum << ") " << getReasonStr(Cand.Reason);
if (P.isValid())
dbgs() << " " << TRI->getRegPressureSetName(P.PSetID)
<< ":" << P.UnitIncrease << " ";
dbgs() << " " << TRI->getRegPressureSetName(P.getPSet())
<< ":" << P.getUnitInc() << " ";
else
dbgs() << " ";
if (ResIdx)