[MachineScheduler]Add support for store clustering
Perform store clustering just like load clustering. This change add
StoreClusterMutation in machine-scheduler. To control StoreClusterMutation,
added enableClusterStores() in TargetInstrInfo.h. This is enabled only on
AArch64 for now.
This change also add support for unscaled stores which were not handled in
getMemOpBaseRegImmOfs().
llvm-svn: 266437
diff --git a/llvm/lib/CodeGen/MachineScheduler.cpp b/llvm/lib/CodeGen/MachineScheduler.cpp
index 9a7cae6..b7f73fd 100644
--- a/llvm/lib/CodeGen/MachineScheduler.cpp
+++ b/llvm/lib/CodeGen/MachineScheduler.cpp
@@ -71,8 +71,9 @@
static cl::opt<bool> EnableCyclicPath("misched-cyclicpath", cl::Hidden,
cl::desc("Enable cyclic critical path analysis."), cl::init(true));
-static cl::opt<bool> EnableLoadCluster("misched-cluster", cl::Hidden,
- cl::desc("Enable load clustering."), cl::init(true));
+static cl::opt<bool> EnableMemOpCluster("misched-cluster", cl::Hidden,
+ cl::desc("Enable memop clustering."),
+ cl::init(true));
// Experimental heuristics
static cl::opt<bool> EnableMacroFusion("misched-fusion", cl::Hidden,
@@ -1351,64 +1352,80 @@
}
//===----------------------------------------------------------------------===//
-// LoadClusterMutation - DAG post-processing to cluster loads.
+// BaseMemOpClusterMutation - DAG post-processing to cluster loads or stores.
//===----------------------------------------------------------------------===//
namespace {
/// \brief Post-process the DAG to create cluster edges between neighboring
-/// loads.
-class LoadClusterMutation : public ScheduleDAGMutation {
- struct LoadInfo {
+/// loads or between neighboring stores.
+class BaseMemOpClusterMutation : public ScheduleDAGMutation {
+ struct MemOpInfo {
SUnit *SU;
unsigned BaseReg;
int64_t Offset;
- LoadInfo(SUnit *su, unsigned reg, int64_t ofs)
- : SU(su), BaseReg(reg), Offset(ofs) {}
+ MemOpInfo(SUnit *su, unsigned reg, int64_t ofs)
+ : SU(su), BaseReg(reg), Offset(ofs) {}
- bool operator<(const LoadInfo &RHS) const {
+ bool operator<(const MemOpInfo&RHS) const {
return std::tie(BaseReg, Offset) < std::tie(RHS.BaseReg, RHS.Offset);
}
};
const TargetInstrInfo *TII;
const TargetRegisterInfo *TRI;
+ bool IsLoad;
+
public:
- LoadClusterMutation(const TargetInstrInfo *tii,
- const TargetRegisterInfo *tri)
- : TII(tii), TRI(tri) {}
+ BaseMemOpClusterMutation(const TargetInstrInfo *tii,
+ const TargetRegisterInfo *tri, bool IsLoad)
+ : TII(tii), TRI(tri), IsLoad(IsLoad) {}
void apply(ScheduleDAGInstrs *DAGInstrs) override;
+
protected:
- void clusterNeighboringLoads(ArrayRef<SUnit*> Loads, ScheduleDAGMI *DAG);
+ void clusterNeighboringMemOps(ArrayRef<SUnit *> MemOps, ScheduleDAGMI *DAG);
+};
+
+class StoreClusterMutation : public BaseMemOpClusterMutation {
+public:
+ StoreClusterMutation(const TargetInstrInfo *tii,
+ const TargetRegisterInfo *tri)
+ : BaseMemOpClusterMutation(tii, tri, false) {}
+};
+
+class LoadClusterMutation : public BaseMemOpClusterMutation {
+public:
+ LoadClusterMutation(const TargetInstrInfo *tii, const TargetRegisterInfo *tri)
+ : BaseMemOpClusterMutation(tii, tri, true) {}
};
} // anonymous
-void LoadClusterMutation::clusterNeighboringLoads(ArrayRef<SUnit*> Loads,
- ScheduleDAGMI *DAG) {
- SmallVector<LoadClusterMutation::LoadInfo,32> LoadRecords;
- for (unsigned Idx = 0, End = Loads.size(); Idx != End; ++Idx) {
- SUnit *SU = Loads[Idx];
+void BaseMemOpClusterMutation::clusterNeighboringMemOps(
+ ArrayRef<SUnit *> MemOps, ScheduleDAGMI *DAG) {
+ SmallVector<MemOpInfo, 32> MemOpRecords;
+ for (unsigned Idx = 0, End = MemOps.size(); Idx != End; ++Idx) {
+ SUnit *SU = MemOps[Idx];
unsigned BaseReg;
int64_t Offset;
if (TII->getMemOpBaseRegImmOfs(SU->getInstr(), BaseReg, Offset, TRI))
- LoadRecords.push_back(LoadInfo(SU, BaseReg, Offset));
+ MemOpRecords.push_back(MemOpInfo(SU, BaseReg, Offset));
}
- if (LoadRecords.size() < 2)
+ if (MemOpRecords.size() < 2)
return;
- std::sort(LoadRecords.begin(), LoadRecords.end());
+
+ std::sort(MemOpRecords.begin(), MemOpRecords.end());
unsigned ClusterLength = 1;
- for (unsigned Idx = 0, End = LoadRecords.size(); Idx < (End - 1); ++Idx) {
- if (LoadRecords[Idx].BaseReg != LoadRecords[Idx+1].BaseReg) {
+ for (unsigned Idx = 0, End = MemOpRecords.size(); Idx < (End - 1); ++Idx) {
+ if (MemOpRecords[Idx].BaseReg != MemOpRecords[Idx+1].BaseReg) {
ClusterLength = 1;
continue;
}
- SUnit *SUa = LoadRecords[Idx].SU;
- SUnit *SUb = LoadRecords[Idx+1].SU;
- if (TII->shouldClusterLoads(SUa->getInstr(), SUb->getInstr(), ClusterLength)
+ SUnit *SUa = MemOpRecords[Idx].SU;
+ SUnit *SUb = MemOpRecords[Idx+1].SU;
+ if (TII->shouldClusterMemOps(SUa->getInstr(), SUb->getInstr(), ClusterLength)
&& DAG->addEdge(SUb, SDep(SUa, SDep::Cluster))) {
-
- DEBUG(dbgs() << "Cluster loads SU(" << SUa->NodeNum << ") - SU("
+ DEBUG(dbgs() << "Cluster ld/st SU(" << SUa->NodeNum << ") - SU("
<< SUb->NodeNum << ")\n");
// Copy successor edges from SUa to SUb. Interleaving computation
// dependent on SUa can prevent load combining due to register reuse.
@@ -1429,17 +1446,20 @@
}
/// \brief Callback from DAG postProcessing to create cluster edges for loads.
-void LoadClusterMutation::apply(ScheduleDAGInstrs *DAGInstrs) {
+void BaseMemOpClusterMutation::apply(ScheduleDAGInstrs *DAGInstrs) {
+
ScheduleDAGMI *DAG = static_cast<ScheduleDAGMI*>(DAGInstrs);
// Map DAG NodeNum to store chain ID.
DenseMap<unsigned, unsigned> StoreChainIDs;
- // Map each store chain to a set of dependent loads.
+ // Map each store chain to a set of dependent MemOps.
SmallVector<SmallVector<SUnit*,4>, 32> StoreChainDependents;
for (unsigned Idx = 0, End = DAG->SUnits.size(); Idx != End; ++Idx) {
SUnit *SU = &DAG->SUnits[Idx];
- if (!SU->getInstr()->mayLoad())
+ if ((IsLoad && !SU->getInstr()->mayLoad()) ||
+ (!IsLoad && !SU->getInstr()->mayStore()))
continue;
+
unsigned ChainPredID = DAG->SUnits.size();
for (SUnit::const_pred_iterator
PI = SU->Preds.begin(), PE = SU->Preds.end(); PI != PE; ++PI) {
@@ -1449,7 +1469,7 @@
}
}
// Check if this chain-like pred has been seen
- // before. ChainPredID==MaxNodeID for loads at the top of the schedule.
+ // before. ChainPredID==MaxNodeID at the top of the schedule.
unsigned NumChains = StoreChainDependents.size();
std::pair<DenseMap<unsigned, unsigned>::iterator, bool> Result =
StoreChainIDs.insert(std::make_pair(ChainPredID, NumChains));
@@ -1457,9 +1477,10 @@
StoreChainDependents.resize(NumChains + 1);
StoreChainDependents[Result.first->second].push_back(SU);
}
+
// Iterate over the store chains.
for (unsigned Idx = 0, End = StoreChainDependents.size(); Idx != End; ++Idx)
- clusterNeighboringLoads(StoreChainDependents[Idx], DAG);
+ clusterNeighboringMemOps(StoreChainDependents[Idx], DAG);
}
//===----------------------------------------------------------------------===//
@@ -3054,8 +3075,12 @@
// data and pass it to later mutations. Have a single mutation that gathers
// the interesting nodes in one pass.
DAG->addMutation(make_unique<CopyConstrain>(DAG->TII, DAG->TRI));
- if (EnableLoadCluster && DAG->TII->enableClusterLoads())
- DAG->addMutation(make_unique<LoadClusterMutation>(DAG->TII, DAG->TRI));
+ if (EnableMemOpCluster) {
+ if (DAG->TII->enableClusterLoads())
+ DAG->addMutation(make_unique<LoadClusterMutation>(DAG->TII, DAG->TRI));
+ if (DAG->TII->enableClusterStores())
+ DAG->addMutation(make_unique<StoreClusterMutation>(DAG->TII, DAG->TRI));
+ }
if (EnableMacroFusion)
DAG->addMutation(make_unique<MacroFusion>(*DAG->TII, *DAG->TRI));
return DAG;