//
//===----------------------------------------------------------------------===//
-#define DEBUG_TYPE "early-ifcvt"
+#define DEBUG_TYPE "machine-trace-metrics"
#include "MachineTraceMetrics.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineBranchProbabilityInfo.h"
#include "llvm/CodeGen/MachineLoopInfo.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/Passes.h"
+#include "llvm/MC/MCSubtargetInfo.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetRegisterInfo.h"
+#include "llvm/Target/TargetSubtargetInfo.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/ADT/PostOrderIterator.h"
MF = &Func;
TII = MF->getTarget().getInstrInfo();
TRI = MF->getTarget().getRegisterInfo();
- ItinData = MF->getTarget().getInstrItineraryData();
MRI = &MF->getRegInfo();
Loops = &getAnalysis<MachineLoopInfo>();
+ const TargetSubtargetInfo &ST =
+ MF->getTarget().getSubtarget<TargetSubtargetInfo>();
+ SchedModel.init(*ST.getSchedModel(), &ST, TII);
BlockInfo.resize(MF->getNumBlockIDs());
return false;
}
const MachineBasicBlock *Pred = *I;
const MachineTraceMetrics::TraceBlockInfo *PredTBI =
getDepthResources(Pred);
- assert(PredTBI && "Predecessor must be visited first");
+ // Ignore cycles that aren't natural loops.
+ if (!PredTBI)
+ continue;
// Pick the predecessor that would give this block the smallest InstrDepth.
unsigned Depth = PredTBI->InstrDepth + CurCount;
if (!Best || Depth < BestDepth)
continue;
const MachineTraceMetrics::TraceBlockInfo *SuccTBI =
getHeightResources(Succ);
- assert(SuccTBI && "Successor must be visited first");
+ // Ignore cycles that aren't natural loops.
+ if (!SuccTBI)
+ continue;
// Pick the successor that would give this block the smallest InstrHeight.
unsigned Height = SuccTBI->InstrHeight;
if (!Best || Height < BestHeight)
namespace {
struct LoopBounds {
MutableArrayRef<MachineTraceMetrics::TraceBlockInfo> Blocks;
+ SmallPtrSet<const MachineBasicBlock*, 8> Visited;
const MachineLoopInfo *Loops;
bool Downward;
LoopBounds(MutableArrayRef<MachineTraceMetrics::TraceBlockInfo> blocks,
if (LB.Downward ? TBI.hasValidHeight() : TBI.hasValidDepth())
return false;
// From is null once when To is the trace center block.
- if (!From)
- return true;
- const MachineLoop *FromLoop = LB.Loops->getLoopFor(From);
- if (!FromLoop)
- return true;
- // Don't follow backedges, don't leave FromLoop when going upwards.
- if ((LB.Downward ? To : From) == FromLoop->getHeader())
- return false;
- // Don't leave FromLoop.
- if (isExitingLoop(FromLoop, LB.Loops->getLoopFor(To)))
- return false;
- // This is a new block. The PO traversal will compute height/depth
- // resources, causing us to reject new edges to To. This only works because
- // we reject back-edges, so the CFG is cycle-free.
- return true;
+ if (From) {
+ if (const MachineLoop *FromLoop = LB.Loops->getLoopFor(From)) {
+ // Don't follow backedges, don't leave FromLoop when going upwards.
+ if ((LB.Downward ? To : From) == FromLoop->getHeader())
+ return false;
+ // Don't leave FromLoop.
+ if (isExitingLoop(FromLoop, LB.Loops->getLoopFor(To)))
+ return false;
+ }
+ }
+ // To is a new block. Mark the block as visited in case the CFG has cycles
+ // that MachineLoopInfo didn't recognize as a natural loop.
+ return LB.Visited.insert(To);
}
};
}
// Run an upwards post-order search for the trace start.
Bounds.Downward = false;
+ Bounds.Visited.clear();
typedef ipo_ext_iterator<const MachineBasicBlock*, LoopBounds> UpwardPO;
for (UpwardPO I = ipo_ext_begin(MBB, Bounds), E = ipo_ext_end(MBB, Bounds);
I != E; ++I) {
// Run a downwards post-order search for the trace end.
Bounds.Downward = true;
+ Bounds.Visited.clear();
typedef po_ext_iterator<const MachineBasicBlock*, LoopBounds> DownwardPO;
for (DownwardPO I = po_ext_begin(MBB, Bounds), E = po_ext_end(MBB, Bounds);
I != E; ++I) {
}
// Keep track of physreg data dependencies by recording each live register unit.
+// Associate each regunit with an instruction operand. Depending on the
+// direction instructions are scanned, it could be the operand that defined the
+// regunit, or the highest operand to read the regunit.
namespace {
struct LiveRegUnit {
unsigned RegUnit;
- unsigned DefOp;
- const MachineInstr *DefMI;
+ unsigned Cycle;
+ const MachineInstr *MI;
+ unsigned Op;
unsigned getSparseSetIndex() const { return RegUnit; }
- LiveRegUnit(unsigned RU, const MachineInstr *MI = 0, unsigned OpNo = 0)
- : RegUnit(RU), DefOp(OpNo), DefMI(MI) {}
+ LiveRegUnit(unsigned RU) : RegUnit(RU), Cycle(0), MI(0), Op(0) {}
};
}
SparseSet<LiveRegUnit>::iterator I = RegUnits.find(*Units);
if (I == RegUnits.end())
continue;
- Deps.push_back(DataDep(I->DefMI, I->DefOp, MO.getOperandNo()));
+ Deps.push_back(DataDep(I->MI, I->Op, MO.getOperandNo()));
break;
}
}
for (MCRegUnitIterator Units(UseMI->getOperand(DefOp).getReg(), TRI);
Units.isValid(); ++Units) {
LiveRegUnit &LRU = RegUnits[*Units];
- LRU.DefMI = UseMI;
- LRU.DefOp = DefOp;
+ LRU.MI = UseMI;
+ LRU.Op = DefOp;
}
}
}
-
-
+/// The length of the critical path through a trace is the maximum of two path
+/// lengths:
+///
+/// 1. The maximum height+depth over all instructions in the trace center block.
+///
+/// 2. The longest cross-block dependency chain. For small blocks, it is
+/// possible that the critical path through the trace doesn't include any
+/// instructions in the block.
+///
+/// This function computes the second number from the live-in list of the
+/// center block.
+unsigned MachineTraceMetrics::Ensemble::
+computeCrossBlockCriticalPath(const TraceBlockInfo &TBI) {
+ assert(TBI.HasValidInstrDepths && "Missing depth info");
+ assert(TBI.HasValidInstrHeights && "Missing height info");
+ unsigned MaxLen = 0;
+ for (unsigned i = 0, e = TBI.LiveIns.size(); i != e; ++i) {
+ const LiveInReg &LIR = TBI.LiveIns[i];
+ if (!TargetRegisterInfo::isVirtualRegister(LIR.Reg))
+ continue;
+ const MachineInstr *DefMI = MTM.MRI->getVRegDef(LIR.Reg);
+ // Ignore dependencies outside the current trace.
+ const TraceBlockInfo &DefTBI = BlockInfo[DefMI->getParent()->getNumber()];
+ if (!DefTBI.hasValidDepth() || DefTBI.Head != TBI.Head)
+ continue;
+ unsigned Len = LIR.Height + Cycles[DefMI].Depth;
+ MaxLen = std::max(MaxLen, Len);
+ }
+ return MaxLen;
+}
/// Compute instruction depths for all instructions above or in MBB in its
/// trace. This assumes that the trace through MBB has already been computed.
DEBUG(dbgs() << "Depths for BB#" << MBB->getNumber() << ":\n");
TraceBlockInfo &TBI = BlockInfo[MBB->getNumber()];
TBI.HasValidInstrDepths = true;
+ TBI.CriticalPath = 0;
+
+ // Also compute the critical path length through MBB when possible.
+ if (TBI.HasValidInstrHeights)
+ TBI.CriticalPath = computeCrossBlockCriticalPath(TBI);
+
for (MachineBasicBlock::const_iterator I = MBB->begin(), E = MBB->end();
I != E; ++I) {
const MachineInstr *UseMI = I;
unsigned DepCycle = Cycles.lookup(Dep.DefMI).Depth;
// Add latency if DefMI is a real instruction. Transients get latency 0.
if (!Dep.DefMI->isTransient())
- DepCycle += MTM.TII->computeOperandLatency(MTM.ItinData,
- Dep.DefMI, Dep.DefOp,
- UseMI, Dep.UseOp,
- /* FindMin = */ false);
+ DepCycle += MTM.SchedModel
+ .computeOperandLatency(Dep.DefMI, Dep.DefOp, UseMI, Dep.UseOp,
+ /* FindMin = */ false);
Cycle = std::max(Cycle, DepCycle);
}
// Remember the instruction depth.
- Cycles[UseMI].Depth = Cycle;
- DEBUG(dbgs() << Cycle << '\t' << *UseMI);
+ InstrCycles &MICycles = Cycles[UseMI];
+ MICycles.Depth = Cycle;
+
+ if (!TBI.HasValidInstrHeights) {
+ DEBUG(dbgs() << Cycle << '\t' << *UseMI);
+ continue;
+ }
+ // Update critical path length.
+ TBI.CriticalPath = std::max(TBI.CriticalPath, Cycle + MICycles.Height);
+ DEBUG(dbgs() << TBI.CriticalPath << '\t' << Cycle << '\t' << *UseMI);
+ }
+ }
+}
+
+// Identify physreg dependencies for MI when scanning instructions upwards.
+// Return the issue height of MI after considering any live regunits.
+// Height is the issue height computed from virtual register dependencies alone.
+static unsigned updatePhysDepsUpwards(const MachineInstr *MI, unsigned Height,
+ SparseSet<LiveRegUnit> &RegUnits,
+ const TargetSchedModel &SchedModel,
+ const TargetInstrInfo *TII,
+ const TargetRegisterInfo *TRI) {
+ SmallVector<unsigned, 8> ReadOps;
+ for (ConstMIOperands MO(MI); MO.isValid(); ++MO) {
+ if (!MO->isReg())
+ continue;
+ unsigned Reg = MO->getReg();
+ if (!TargetRegisterInfo::isPhysicalRegister(Reg))
+ continue;
+ if (MO->readsReg())
+ ReadOps.push_back(MO.getOperandNo());
+ if (!MO->isDef())
+ continue;
+ // This is a def of Reg. Remove corresponding entries from RegUnits, and
+ // update MI Height to consider the physreg dependencies.
+ for (MCRegUnitIterator Units(Reg, TRI); Units.isValid(); ++Units) {
+ SparseSet<LiveRegUnit>::iterator I = RegUnits.find(*Units);
+ if (I == RegUnits.end())
+ continue;
+ unsigned DepHeight = I->Cycle;
+ if (!MI->isTransient()) {
+ // We may not know the UseMI of this dependency, if it came from the
+ // live-in list. SchedModel can handle a NULL UseMI.
+ DepHeight += SchedModel
+ .computeOperandLatency(MI, MO.getOperandNo(), I->MI, I->Op,
+ /* FindMin = */ false);
+ }
+ Height = std::max(Height, DepHeight);
+ // This regunit is dead above MI.
+ RegUnits.erase(I);
+ }
+ }
+
+ // Now we know the height of MI. Update any regunits read.
+ for (unsigned i = 0, e = ReadOps.size(); i != e; ++i) {
+ unsigned Reg = MI->getOperand(ReadOps[i]).getReg();
+ for (MCRegUnitIterator Units(Reg, TRI); Units.isValid(); ++Units) {
+ LiveRegUnit &LRU = RegUnits[*Units];
+ // Set the height to the highest reader of the unit.
+ if (LRU.Cycle <= Height && LRU.MI != MI) {
+ LRU.Cycle = Height;
+ LRU.MI = MI;
+ LRU.Op = ReadOps[i];
+ }
}
}
+
+ return Height;
+}
+
+
+typedef DenseMap<const MachineInstr *, unsigned> MIHeightMap;
+
+// Push the height of DefMI upwards if required to match UseMI.
+// Return true if this is the first time DefMI was seen.
+static bool pushDepHeight(const DataDep &Dep,
+ const MachineInstr *UseMI, unsigned UseHeight,
+ MIHeightMap &Heights,
+ const TargetSchedModel &SchedModel,
+ const TargetInstrInfo *TII) {
+ // Adjust height by Dep.DefMI latency.
+ if (!Dep.DefMI->isTransient())
+ UseHeight += SchedModel.computeOperandLatency(Dep.DefMI, Dep.DefOp,
+ UseMI, Dep.UseOp, false);
+
+ // Update Heights[DefMI] to be the maximum height seen.
+ MIHeightMap::iterator I;
+ bool New;
+ tie(I, New) = Heights.insert(std::make_pair(Dep.DefMI, UseHeight));
+ if (New)
+ return true;
+
+ // DefMI has been pushed before. Give it the max height.
+ if (I->second < UseHeight)
+ I->second = UseHeight;
+ return false;
+}
+
+/// Assuming that DefMI was used by Trace.back(), add it to the live-in lists
+/// of all the blocks in Trace. Stop when reaching the block that contains
+/// DefMI.
+void MachineTraceMetrics::Ensemble::
+addLiveIns(const MachineInstr *DefMI,
+ ArrayRef<const MachineBasicBlock*> Trace) {
+ assert(!Trace.empty() && "Trace should contain at least one block");
+ unsigned Reg = DefMI->getOperand(0).getReg();
+ assert(TargetRegisterInfo::isVirtualRegister(Reg));
+ const MachineBasicBlock *DefMBB = DefMI->getParent();
+
+ // Reg is live-in to all blocks in Trace that follow DefMBB.
+ for (unsigned i = Trace.size(); i; --i) {
+ const MachineBasicBlock *MBB = Trace[i-1];
+ if (MBB == DefMBB)
+ return;
+ TraceBlockInfo &TBI = BlockInfo[MBB->getNumber()];
+ // Just add the register. The height will be updated later.
+ TBI.LiveIns.push_back(Reg);
+ }
+}
+
+/// Compute instruction heights in the trace through MBB. This updates MBB and
+/// the blocks below it in the trace. It is assumed that the trace has already
+/// been computed.
+void MachineTraceMetrics::Ensemble::
+computeInstrHeights(const MachineBasicBlock *MBB) {
+ // The bottom of the trace may already be computed.
+ // Find the blocks that need updating.
+ SmallVector<const MachineBasicBlock*, 8> Stack;
+ do {
+ TraceBlockInfo &TBI = BlockInfo[MBB->getNumber()];
+ assert(TBI.hasValidHeight() && "Incomplete trace");
+ if (TBI.HasValidInstrHeights)
+ break;
+ Stack.push_back(MBB);
+ TBI.LiveIns.clear();
+ MBB = TBI.Succ;
+ } while (MBB);
+
+ // As we move upwards in the trace, keep track of instructions that are
+ // required by deeper trace instructions. Map MI -> height required so far.
+ MIHeightMap Heights;
+
+ // For physregs, the def isn't known when we see the use.
+ // Instead, keep track of the highest use of each regunit.
+ SparseSet<LiveRegUnit> RegUnits;
+ RegUnits.setUniverse(MTM.TRI->getNumRegUnits());
+
+ // If the bottom of the trace was already precomputed, initialize heights
+ // from its live-in list.
+ // MBB is the highest precomputed block in the trace.
+ if (MBB) {
+ TraceBlockInfo &TBI = BlockInfo[MBB->getNumber()];
+ for (unsigned i = 0, e = TBI.LiveIns.size(); i != e; ++i) {
+ LiveInReg LI = TBI.LiveIns[i];
+ if (TargetRegisterInfo::isVirtualRegister(LI.Reg)) {
+ // For virtual registers, the def latency is included.
+ unsigned &Height = Heights[MTM.MRI->getVRegDef(LI.Reg)];
+ if (Height < LI.Height)
+ Height = LI.Height;
+ } else {
+ // For register units, the def latency is not included because we don't
+ // know the def yet.
+ RegUnits[LI.Reg].Cycle = LI.Height;
+ }
+ }
+ }
+
+ // Go through the trace blocks in bottom-up order.
+ SmallVector<DataDep, 8> Deps;
+ for (;!Stack.empty(); Stack.pop_back()) {
+ MBB = Stack.back();
+ DEBUG(dbgs() << "Heights for BB#" << MBB->getNumber() << ":\n");
+ TraceBlockInfo &TBI = BlockInfo[MBB->getNumber()];
+ TBI.HasValidInstrHeights = true;
+ TBI.CriticalPath = 0;
+
+ // 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
+ // loop header, get loop-carried dependencies from PHIs in the header. For
+ // that purpose, pretend that all the loop header PHIs have height 0.
+ if (!Succ)
+ if (const MachineLoop *Loop = getLoopFor(MBB))
+ if (MBB->isSuccessor(Loop->getHeader()))
+ Succ = Loop->getHeader();
+
+ if (Succ) {
+ for (MachineBasicBlock::const_iterator I = Succ->begin(), E = Succ->end();
+ I != E && I->isPHI(); ++I) {
+ const MachineInstr *PHI = I;
+ Deps.clear();
+ getPHIDeps(PHI, Deps, MBB, MTM.MRI);
+ if (!Deps.empty()) {
+ // Loop header PHI heights are all 0.
+ unsigned Height = TBI.Succ ? Cycles.lookup(PHI).Height : 0;
+ DEBUG(dbgs() << "pred\t" << Height << '\t' << *PHI);
+ if (pushDepHeight(Deps.front(), PHI, Height,
+ Heights, MTM.SchedModel, MTM.TII))
+ addLiveIns(Deps.front().DefMI, Stack);
+ }
+ }
+ }
+
+ // Go through the block backwards.
+ for (MachineBasicBlock::const_iterator BI = MBB->end(), BB = MBB->begin();
+ BI != BB;) {
+ const MachineInstr *MI = --BI;
+
+ // Find the MI height as determined by virtual register uses in the
+ // trace below.
+ unsigned Cycle = 0;
+ MIHeightMap::iterator HeightI = Heights.find(MI);
+ if (HeightI != Heights.end()) {
+ Cycle = HeightI->second;
+ // We won't be seeing any more MI uses.
+ Heights.erase(HeightI);
+ }
+
+ // Don't process PHI deps. They depend on the specific predecessor, and
+ // we'll get them when visiting the predecessor.
+ Deps.clear();
+ bool HasPhysRegs = !MI->isPHI() && getDataDeps(MI, Deps, MTM.MRI);
+
+ // There may also be regunit dependencies to include in the height.
+ if (HasPhysRegs)
+ Cycle = updatePhysDepsUpwards(MI, Cycle, RegUnits,
+ MTM.SchedModel, MTM.TII, MTM.TRI);
+
+ // Update the required height of any virtual registers read by MI.
+ for (unsigned i = 0, e = Deps.size(); i != e; ++i)
+ if (pushDepHeight(Deps[i], MI, Cycle, Heights, MTM.SchedModel, MTM.TII))
+ addLiveIns(Deps[i].DefMI, Stack);
+
+ InstrCycles &MICycles = Cycles[MI];
+ MICycles.Height = Cycle;
+ if (!TBI.HasValidInstrDepths) {
+ DEBUG(dbgs() << Cycle << '\t' << *MI);
+ continue;
+ }
+ // Update critical path length.
+ TBI.CriticalPath = std::max(TBI.CriticalPath, Cycle + MICycles.Depth);
+ DEBUG(dbgs() << TBI.CriticalPath << '\t' << Cycle << '\t' << *MI);
+ }
+
+ // Update virtual live-in heights. They were added by addLiveIns() with a 0
+ // height because the final height isn't known until now.
+ DEBUG(dbgs() << "BB#" << MBB->getNumber() << " Live-ins:");
+ for (unsigned i = 0, e = TBI.LiveIns.size(); i != e; ++i) {
+ LiveInReg &LIR = TBI.LiveIns[i];
+ const MachineInstr *DefMI = MTM.MRI->getVRegDef(LIR.Reg);
+ LIR.Height = Heights.lookup(DefMI);
+ DEBUG(dbgs() << ' ' << PrintReg(LIR.Reg) << '@' << LIR.Height);
+ }
+
+ // Transfer the live regunits to the live-in list.
+ for (SparseSet<LiveRegUnit>::const_iterator
+ RI = RegUnits.begin(), RE = RegUnits.end(); RI != RE; ++RI) {
+ TBI.LiveIns.push_back(LiveInReg(RI->RegUnit, RI->Cycle));
+ DEBUG(dbgs() << ' ' << PrintRegUnit(RI->RegUnit, MTM.TRI)
+ << '@' << RI->Cycle);
+ }
+ DEBUG(dbgs() << '\n');
+
+ if (!TBI.HasValidInstrDepths)
+ continue;
+ // Add live-ins to the critical path length.
+ TBI.CriticalPath = std::max(TBI.CriticalPath,
+ computeCrossBlockCriticalPath(TBI));
+ DEBUG(dbgs() << "Critical path: " << TBI.CriticalPath << '\n');
+ }
}
MachineTraceMetrics::Trace
// FIXME: Check cache tags, recompute as needed.
computeTrace(MBB);
computeInstrDepths(MBB);
+ computeInstrHeights(MBB);
return Trace(*this, BlockInfo[MBB->getNumber()]);
}
+unsigned
+MachineTraceMetrics::Trace::getInstrSlack(const MachineInstr *MI) const {
+ assert(MI && "Not an instruction.");
+ assert(getBlockNum() == unsigned(MI->getParent()->getNumber()) &&
+ "MI must be in the trace center block");
+ InstrCycles Cyc = getInstrCycles(MI);
+ return getCriticalPath() - (Cyc.Depth + Cyc.Height);
+}
+
+unsigned
+MachineTraceMetrics::Trace::getPHIDepth(const MachineInstr *PHI) const {
+ const MachineBasicBlock *MBB = TE.MTM.MF->getBlockNumbered(getBlockNum());
+ SmallVector<DataDep, 1> Deps;
+ getPHIDeps(PHI, Deps, MBB, TE.MTM.MRI);
+ assert(Deps.size() == 1 && "PHI doesn't have MBB as a predecessor");
+ DataDep &Dep = Deps.front();
+ unsigned DepCycle = getInstrCycles(Dep.DefMI).Depth;
+ // Add latency if DefMI is a real instruction. Transients get latency 0.
+ if (!Dep.DefMI->isTransient())
+ DepCycle += TE.MTM.SchedModel
+ .computeOperandLatency(Dep.DefMI, Dep.DefOp, PHI, Dep.UseOp, false);
+ return DepCycle;
+}
+
+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.
+ 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;
+}
+
+unsigned MachineTraceMetrics::Trace::
+getResourceLength(ArrayRef<const MachineBasicBlock*> Extrablocks) const {
+ 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;
+}
+
void MachineTraceMetrics::Ensemble::print(raw_ostream &OS) const {
OS << getName() << " ensemble:\n";
for (unsigned i = 0, e = BlockInfo.size(); i != e; ++i) {
OS << " +instrs";
} else
OS << "height invalid";
+ if (HasValidInstrDepths && HasValidInstrHeights)
+ OS << ", crit=" << CriticalPath;
}
void MachineTraceMetrics::Trace::print(raw_ostream &OS) const {
<< " --> BB#" << TBI.Tail << ':';
if (TBI.hasValidHeight() && TBI.hasValidDepth())
OS << ' ' << getInstrCount() << " instrs.";
+ if (TBI.HasValidInstrDepths && TBI.HasValidInstrHeights)
+ OS << ' ' << TBI.CriticalPath << " cycles.";
const MachineTraceMetrics::TraceBlockInfo *Block = &TBI;
OS << "\nBB#" << MBBNum;