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-rw-r--r--lib/CodeGen/MachineTraceMetrics.cpp153
1 files changed, 144 insertions, 9 deletions
diff --git a/lib/CodeGen/MachineTraceMetrics.cpp b/lib/CodeGen/MachineTraceMetrics.cpp
index 5bf0176ead..c154b5c9c1 100644
--- a/lib/CodeGen/MachineTraceMetrics.cpp
+++ b/lib/CodeGen/MachineTraceMetrics.cpp
@@ -18,6 +18,7 @@
#include "llvm/CodeGen/Passes.h"
#include "llvm/MC/MCSubtargetInfo.h"
#include "llvm/Support/Debug.h"
+#include "llvm/Support/Format.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetRegisterInfo.h"
@@ -57,6 +58,8 @@ bool MachineTraceMetrics::runOnMachineFunction(MachineFunction &Func) {
MF->getTarget().getSubtarget<TargetSubtargetInfo>();
SchedModel.init(*ST.getSchedModel(), &ST, TII);
BlockInfo.resize(MF->getNumBlockIDs());
+ ProcResourceCycles.resize(MF->getNumBlockIDs() *
+ SchedModel.getNumProcResourceKinds());
return false;
}
@@ -85,9 +88,13 @@ MachineTraceMetrics::getResources(const MachineBasicBlock *MBB) {
return FBI;
// Compute resource usage in the block.
- // FIXME: Compute per-functional unit counts.
FBI->HasCalls = false;
unsigned InstrCount = 0;
+
+ // Add up per-processor resource cycles as well.
+ unsigned PRKinds = SchedModel.getNumProcResourceKinds();
+ SmallVector<unsigned, 32> PRCycles(PRKinds);
+
for (MachineBasicBlock::const_iterator I = MBB->begin(), E = MBB->end();
I != E; ++I) {
const MachineInstr *MI = I;
@@ -96,11 +103,39 @@ MachineTraceMetrics::getResources(const MachineBasicBlock *MBB) {
++InstrCount;
if (MI->isCall())
FBI->HasCalls = true;
+
+ // Count processor resources used.
+ const MCSchedClassDesc *SC = SchedModel.resolveSchedClass(MI);
+ if (!SC->isValid())
+ continue;
+
+ for (TargetSchedModel::ProcResIter
+ PI = SchedModel.getWriteProcResBegin(SC),
+ PE = SchedModel.getWriteProcResEnd(SC); PI != PE; ++PI) {
+ assert(PI->ProcResourceIdx < PRKinds && "Bad processor resource kind");
+ PRCycles[PI->ProcResourceIdx] += PI->Cycles;
+ }
}
FBI->InstrCount = InstrCount;
+
+ // Scale the resource cycles so they are comparable.
+ unsigned PROffset = MBB->getNumber() * PRKinds;
+ for (unsigned K = 0; K != PRKinds; ++K)
+ ProcResourceCycles[PROffset + K] =
+ PRCycles[K] * SchedModel.getResourceFactor(K);
+
return FBI;
}
+ArrayRef<unsigned>
+MachineTraceMetrics::getProcResourceCycles(unsigned MBBNum) const {
+ assert(BlockInfo[MBBNum].hasResources() &&
+ "getResources() must be called before getProcResourceCycles()");
+ unsigned PRKinds = SchedModel.getNumProcResourceKinds();
+ return ArrayRef<unsigned>(&ProcResourceCycles[MBBNum * PRKinds], PRKinds);
+}
+
+
//===----------------------------------------------------------------------===//
// Ensemble utility functions
//===----------------------------------------------------------------------===//
@@ -108,6 +143,9 @@ MachineTraceMetrics::getResources(const MachineBasicBlock *MBB) {
MachineTraceMetrics::Ensemble::Ensemble(MachineTraceMetrics *ct)
: MTM(*ct) {
BlockInfo.resize(MTM.BlockInfo.size());
+ unsigned PRKinds = MTM.SchedModel.getNumProcResourceKinds();
+ ProcResourceDepths.resize(MTM.BlockInfo.size() * PRKinds);
+ ProcResourceHeights.resize(MTM.BlockInfo.size() * PRKinds);
}
// Virtual destructor serves as an anchor.
@@ -123,21 +161,32 @@ MachineTraceMetrics::Ensemble::getLoopFor(const MachineBasicBlock *MBB) const {
void MachineTraceMetrics::Ensemble::
computeDepthResources(const MachineBasicBlock *MBB) {
TraceBlockInfo *TBI = &BlockInfo[MBB->getNumber()];
+ unsigned PRKinds = MTM.SchedModel.getNumProcResourceKinds();
+ unsigned PROffset = MBB->getNumber() * PRKinds;
// Compute resources from trace above. The top block is simple.
if (!TBI->Pred) {
TBI->InstrDepth = 0;
TBI->Head = MBB->getNumber();
+ std::fill(ProcResourceDepths.begin() + PROffset,
+ ProcResourceDepths.begin() + PROffset + PRKinds, 0);
return;
}
// Compute from the block above. A post-order traversal ensures the
// predecessor is always computed first.
- TraceBlockInfo *PredTBI = &BlockInfo[TBI->Pred->getNumber()];
+ unsigned PredNum = TBI->Pred->getNumber();
+ TraceBlockInfo *PredTBI = &BlockInfo[PredNum];
assert(PredTBI->hasValidDepth() && "Trace above has not been computed yet");
const FixedBlockInfo *PredFBI = MTM.getResources(TBI->Pred);
TBI->InstrDepth = PredTBI->InstrDepth + PredFBI->InstrCount;
TBI->Head = PredTBI->Head;
+
+ // Compute per-resource depths.
+ ArrayRef<unsigned> PredPRDepths = getProcResourceDepths(PredNum);
+ ArrayRef<unsigned> PredPRCycles = MTM.getProcResourceCycles(PredNum);
+ for (unsigned K = 0; K != PRKinds; ++K)
+ ProcResourceDepths[PROffset + K] = PredPRDepths[K] + PredPRCycles[K];
}
// Update resource-related information in the TraceBlockInfo for MBB.
@@ -145,22 +194,33 @@ computeDepthResources(const MachineBasicBlock *MBB) {
void MachineTraceMetrics::Ensemble::
computeHeightResources(const MachineBasicBlock *MBB) {
TraceBlockInfo *TBI = &BlockInfo[MBB->getNumber()];
+ unsigned PRKinds = MTM.SchedModel.getNumProcResourceKinds();
+ unsigned PROffset = MBB->getNumber() * PRKinds;
// Compute resources for the current block.
TBI->InstrHeight = MTM.getResources(MBB)->InstrCount;
+ ArrayRef<unsigned> PRCycles = MTM.getProcResourceCycles(MBB->getNumber());
// The trace tail is done.
if (!TBI->Succ) {
TBI->Tail = MBB->getNumber();
+ std::copy(PRCycles.begin(), PRCycles.end(),
+ ProcResourceHeights.begin() + PROffset);
return;
}
// Compute from the block below. A post-order traversal ensures the
// predecessor is always computed first.
- TraceBlockInfo *SuccTBI = &BlockInfo[TBI->Succ->getNumber()];
+ unsigned SuccNum = TBI->Succ->getNumber();
+ TraceBlockInfo *SuccTBI = &BlockInfo[SuccNum];
assert(SuccTBI->hasValidHeight() && "Trace below has not been computed yet");
TBI->InstrHeight += SuccTBI->InstrHeight;
TBI->Tail = SuccTBI->Tail;
+
+ // Compute per-resource heights.
+ ArrayRef<unsigned> SuccPRHeights = getProcResourceHeights(SuccNum);
+ for (unsigned K = 0; K != PRKinds; ++K)
+ ProcResourceHeights[PROffset + K] = SuccPRHeights[K] + PRCycles[K];
}
// Check if depth resources for MBB are valid and return the TBI.
@@ -181,6 +241,31 @@ getHeightResources(const MachineBasicBlock *MBB) const {
return TBI->hasValidHeight() ? TBI : 0;
}
+/// Get an array of processor resource depths for MBB. Indexed by processor
+/// resource kind, this array contains the scaled processor resources consumed
+/// by all blocks preceding MBB in its trace. It does not include instructions
+/// in MBB.
+///
+/// Compare TraceBlockInfo::InstrDepth.
+ArrayRef<unsigned>
+MachineTraceMetrics::Ensemble::
+getProcResourceDepths(unsigned MBBNum) const {
+ unsigned PRKinds = MTM.SchedModel.getNumProcResourceKinds();
+ return ArrayRef<unsigned>(&ProcResourceDepths[MBBNum * PRKinds], PRKinds);
+}
+
+/// Get an array of processor resource heights for MBB. Indexed by processor
+/// resource kind, this array contains the scaled processor resources consumed
+/// by this block and all blocks following it in its trace.
+///
+/// Compare TraceBlockInfo::InstrHeight.
+ArrayRef<unsigned>
+MachineTraceMetrics::Ensemble::
+getProcResourceHeights(unsigned MBBNum) const {
+ unsigned PRKinds = MTM.SchedModel.getNumProcResourceKinds();
+ return ArrayRef<unsigned>(&ProcResourceHeights[MBBNum * PRKinds], PRKinds);
+}
+
//===----------------------------------------------------------------------===//
// Trace Selection Strategies
//===----------------------------------------------------------------------===//
@@ -713,11 +798,24 @@ computeInstrDepths(const MachineBasicBlock *MBB) {
SmallVector<DataDep, 8> Deps;
while (!Stack.empty()) {
MBB = Stack.pop_back_val();
- DEBUG(dbgs() << "Depths for BB#" << MBB->getNumber() << ":\n");
+ DEBUG(dbgs() << "\nDepths for BB#" << MBB->getNumber() << ":\n");
TraceBlockInfo &TBI = BlockInfo[MBB->getNumber()];
TBI.HasValidInstrDepths = true;
TBI.CriticalPath = 0;
+ // Print out resource depths here as well.
+ DEBUG({
+ dbgs() << format("%7u Instructions\n", TBI.InstrDepth);
+ ArrayRef<unsigned> PRDepths = getProcResourceDepths(MBB->getNumber());
+ for (unsigned K = 0; K != PRDepths.size(); ++K)
+ if (PRDepths[K]) {
+ unsigned Factor = MTM.SchedModel.getResourceFactor(K);
+ dbgs() << format("%6uc @ ", MTM.getCycles(PRDepths[K]))
+ << MTM.SchedModel.getProcResource(K)->Name << " ("
+ << PRDepths[K]/Factor << " ops x" << Factor << ")\n";
+ }
+ });
+
// Also compute the critical path length through MBB when possible.
if (TBI.HasValidInstrHeights)
TBI.CriticalPath = computeCrossBlockCriticalPath(TBI);
@@ -928,6 +1026,18 @@ computeInstrHeights(const MachineBasicBlock *MBB) {
TBI.HasValidInstrHeights = true;
TBI.CriticalPath = 0;
+ DEBUG({
+ dbgs() << format("%7u Instructions\n", TBI.InstrHeight);
+ ArrayRef<unsigned> PRHeights = getProcResourceHeights(MBB->getNumber());
+ for (unsigned K = 0; K != PRHeights.size(); ++K)
+ if (PRHeights[K]) {
+ unsigned Factor = MTM.SchedModel.getResourceFactor(K);
+ dbgs() << format("%6uc @ ", MTM.getCycles(PRHeights[K]))
+ << MTM.SchedModel.getProcResource(K)->Name << " ("
+ << PRHeights[K]/Factor << " ops x" << Factor << ")\n";
+ }
+ });
+
// Get dependencies from PHIs in the trace successor.
const MachineBasicBlock *Succ = TBI.Succ;
// If MBB is the last block in the trace, and it has a back-edge to the
@@ -1058,27 +1168,52 @@ MachineTraceMetrics::Trace::getPHIDepth(const MachineInstr *PHI) const {
}
unsigned MachineTraceMetrics::Trace::getResourceDepth(bool Bottom) const {
- // For now, we compute the resource depth from instruction count / issue
- // width. Eventually, we should compute resource depth per functional unit
- // and return the max.
+ // Find the limiting processor resource.
+ // Numbers have been pre-scaled to be comparable.
+ unsigned PRMax = 0;
+ ArrayRef<unsigned> PRDepths = TE.getProcResourceDepths(getBlockNum());
+ if (Bottom) {
+ ArrayRef<unsigned> PRCycles = TE.MTM.getProcResourceCycles(getBlockNum());
+ for (unsigned K = 0; K != PRDepths.size(); ++K)
+ PRMax = std::max(PRMax, PRDepths[K] + PRCycles[K]);
+ } else {
+ for (unsigned K = 0; K != PRDepths.size(); ++K)
+ PRMax = std::max(PRMax, PRDepths[K]);
+ }
+ // Convert to cycle count.
+ PRMax = TE.MTM.getCycles(PRMax);
+
unsigned Instrs = TBI.InstrDepth;
if (Bottom)
Instrs += TE.MTM.BlockInfo[getBlockNum()].InstrCount;
if (unsigned IW = TE.MTM.SchedModel.getIssueWidth())
Instrs /= IW;
// Assume issue width 1 without a schedule model.
- return Instrs;
+ return std::max(Instrs, PRMax);
}
unsigned MachineTraceMetrics::Trace::
getResourceLength(ArrayRef<const MachineBasicBlock*> Extrablocks) const {
+ // Add up resources above and below the center block.
+ ArrayRef<unsigned> PRDepths = TE.getProcResourceDepths(getBlockNum());
+ ArrayRef<unsigned> PRHeights = TE.getProcResourceHeights(getBlockNum());
+ unsigned PRMax = 0;
+ for (unsigned K = 0; K != PRDepths.size(); ++K) {
+ unsigned PRCycles = PRDepths[K] + PRHeights[K];
+ for (unsigned I = 0; I != Extrablocks.size(); ++I)
+ PRCycles += TE.MTM.getProcResourceCycles(Extrablocks[I]->getNumber())[K];
+ PRMax = std::max(PRMax, PRCycles);
+ }
+ // Convert to cycle count.
+ PRMax = TE.MTM.getCycles(PRMax);
+
unsigned Instrs = TBI.InstrDepth + TBI.InstrHeight;
for (unsigned i = 0, e = Extrablocks.size(); i != e; ++i)
Instrs += TE.MTM.getResources(Extrablocks[i])->InstrCount;
if (unsigned IW = TE.MTM.SchedModel.getIssueWidth())
Instrs /= IW;
// Assume issue width 1 without a schedule model.
- return Instrs;
+ return std::max(Instrs, PRMax);
}
void MachineTraceMetrics::Ensemble::print(raw_ostream &OS) const {
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