llvm-6502/lib/CodeGen/MachineTraceMetrics.cpp
Pete Cooper 6de6c6aae4 Change MCSchedModel to be a struct of statically initialized data.
This removes static initializers from the backends which generate this data, and also makes this struct match the other Tablegen generated structs in behaviour

Reviewed by Andy Trick and Chandler C

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216919 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-02 17:43:54 +00:00

1327 lines
49 KiB
C++

//===- lib/CodeGen/MachineTraceMetrics.cpp ----------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/MachineTraceMetrics.h"
#include "llvm/ADT/PostOrderIterator.h"
#include "llvm/ADT/SparseSet.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/Support/Debug.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetRegisterInfo.h"
#include "llvm/Target/TargetSubtargetInfo.h"
using namespace llvm;
#define DEBUG_TYPE "machine-trace-metrics"
char MachineTraceMetrics::ID = 0;
char &llvm::MachineTraceMetricsID = MachineTraceMetrics::ID;
INITIALIZE_PASS_BEGIN(MachineTraceMetrics,
"machine-trace-metrics", "Machine Trace Metrics", false, true)
INITIALIZE_PASS_DEPENDENCY(MachineBranchProbabilityInfo)
INITIALIZE_PASS_DEPENDENCY(MachineLoopInfo)
INITIALIZE_PASS_END(MachineTraceMetrics,
"machine-trace-metrics", "Machine Trace Metrics", false, true)
MachineTraceMetrics::MachineTraceMetrics()
: MachineFunctionPass(ID), MF(nullptr), TII(nullptr), TRI(nullptr),
MRI(nullptr), Loops(nullptr) {
std::fill(std::begin(Ensembles), std::end(Ensembles), nullptr);
}
void MachineTraceMetrics::getAnalysisUsage(AnalysisUsage &AU) const {
AU.setPreservesAll();
AU.addRequired<MachineBranchProbabilityInfo>();
AU.addRequired<MachineLoopInfo>();
MachineFunctionPass::getAnalysisUsage(AU);
}
bool MachineTraceMetrics::runOnMachineFunction(MachineFunction &Func) {
MF = &Func;
TII = MF->getSubtarget().getInstrInfo();
TRI = MF->getSubtarget().getRegisterInfo();
MRI = &MF->getRegInfo();
Loops = &getAnalysis<MachineLoopInfo>();
const TargetSubtargetInfo &ST =
MF->getTarget().getSubtarget<TargetSubtargetInfo>();
SchedModel.init(ST.getSchedModel(), &ST, TII);
BlockInfo.resize(MF->getNumBlockIDs());
ProcResourceCycles.resize(MF->getNumBlockIDs() *
SchedModel.getNumProcResourceKinds());
return false;
}
void MachineTraceMetrics::releaseMemory() {
MF = nullptr;
BlockInfo.clear();
for (unsigned i = 0; i != TS_NumStrategies; ++i) {
delete Ensembles[i];
Ensembles[i] = nullptr;
}
}
//===----------------------------------------------------------------------===//
// Fixed block information
//===----------------------------------------------------------------------===//
//
// The number of instructions in a basic block and the CPU resources used by
// those instructions don't depend on any given trace strategy.
/// Compute the resource usage in basic block MBB.
const MachineTraceMetrics::FixedBlockInfo*
MachineTraceMetrics::getResources(const MachineBasicBlock *MBB) {
assert(MBB && "No basic block");
FixedBlockInfo *FBI = &BlockInfo[MBB->getNumber()];
if (FBI->hasResources())
return FBI;
// Compute resource usage in the block.
FBI->HasCalls = false;
unsigned InstrCount = 0;
// Add up per-processor resource cycles as well.
unsigned PRKinds = SchedModel.getNumProcResourceKinds();
SmallVector<unsigned, 32> PRCycles(PRKinds);
for (const auto &MI : *MBB) {
if (MI.isTransient())
continue;
++InstrCount;
if (MI.isCall())
FBI->HasCalls = true;
// Count processor resources used.
if (!SchedModel.hasInstrSchedModel())
continue;
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();
assert((MBBNum+1) * PRKinds <= ProcResourceCycles.size());
return makeArrayRef(ProcResourceCycles.data() + MBBNum * PRKinds, PRKinds);
}
//===----------------------------------------------------------------------===//
// Ensemble utility functions
//===----------------------------------------------------------------------===//
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.
MachineTraceMetrics::Ensemble::~Ensemble() {}
const MachineLoop*
MachineTraceMetrics::Ensemble::getLoopFor(const MachineBasicBlock *MBB) const {
return MTM.Loops->getLoopFor(MBB);
}
// Update resource-related information in the TraceBlockInfo for MBB.
// Only update resources related to the trace above MBB.
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.
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.
// Only update resources related to the trace below 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.
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.
// Return NULL if the resources have been invalidated.
const MachineTraceMetrics::TraceBlockInfo*
MachineTraceMetrics::Ensemble::
getDepthResources(const MachineBasicBlock *MBB) const {
const TraceBlockInfo *TBI = &BlockInfo[MBB->getNumber()];
return TBI->hasValidDepth() ? TBI : nullptr;
}
// Check if height resources for MBB are valid and return the TBI.
// Return NULL if the resources have been invalidated.
const MachineTraceMetrics::TraceBlockInfo*
MachineTraceMetrics::Ensemble::
getHeightResources(const MachineBasicBlock *MBB) const {
const TraceBlockInfo *TBI = &BlockInfo[MBB->getNumber()];
return TBI->hasValidHeight() ? TBI : nullptr;
}
/// 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();
assert((MBBNum+1) * PRKinds <= ProcResourceDepths.size());
return makeArrayRef(ProcResourceDepths.data() + 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();
assert((MBBNum+1) * PRKinds <= ProcResourceHeights.size());
return makeArrayRef(ProcResourceHeights.data() + MBBNum * PRKinds, PRKinds);
}
//===----------------------------------------------------------------------===//
// Trace Selection Strategies
//===----------------------------------------------------------------------===//
//
// A trace selection strategy is implemented as a sub-class of Ensemble. The
// trace through a block B is computed by two DFS traversals of the CFG
// starting from B. One upwards, and one downwards. During the upwards DFS,
// pickTracePred() is called on the post-ordered blocks. During the downwards
// DFS, pickTraceSucc() is called in a post-order.
//
// We never allow traces that leave loops, but we do allow traces to enter
// nested loops. We also never allow traces to contain back-edges.
//
// This means that a loop header can never appear above the center block of a
// trace, except as the trace head. Below the center block, loop exiting edges
// are banned.
//
// Return true if an edge from the From loop to the To loop is leaving a loop.
// Either of To and From can be null.
static bool isExitingLoop(const MachineLoop *From, const MachineLoop *To) {
return From && !From->contains(To);
}
// MinInstrCountEnsemble - Pick the trace that executes the least number of
// instructions.
namespace {
class MinInstrCountEnsemble : public MachineTraceMetrics::Ensemble {
const char *getName() const override { return "MinInstr"; }
const MachineBasicBlock *pickTracePred(const MachineBasicBlock*) override;
const MachineBasicBlock *pickTraceSucc(const MachineBasicBlock*) override;
public:
MinInstrCountEnsemble(MachineTraceMetrics *mtm)
: MachineTraceMetrics::Ensemble(mtm) {}
};
}
// Select the preferred predecessor for MBB.
const MachineBasicBlock*
MinInstrCountEnsemble::pickTracePred(const MachineBasicBlock *MBB) {
if (MBB->pred_empty())
return nullptr;
const MachineLoop *CurLoop = getLoopFor(MBB);
// Don't leave loops, and never follow back-edges.
if (CurLoop && MBB == CurLoop->getHeader())
return nullptr;
unsigned CurCount = MTM.getResources(MBB)->InstrCount;
const MachineBasicBlock *Best = nullptr;
unsigned BestDepth = 0;
for (MachineBasicBlock::const_pred_iterator
I = MBB->pred_begin(), E = MBB->pred_end(); I != E; ++I) {
const MachineBasicBlock *Pred = *I;
const MachineTraceMetrics::TraceBlockInfo *PredTBI =
getDepthResources(Pred);
// 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)
Best = Pred, BestDepth = Depth;
}
return Best;
}
// Select the preferred successor for MBB.
const MachineBasicBlock*
MinInstrCountEnsemble::pickTraceSucc(const MachineBasicBlock *MBB) {
if (MBB->pred_empty())
return nullptr;
const MachineLoop *CurLoop = getLoopFor(MBB);
const MachineBasicBlock *Best = nullptr;
unsigned BestHeight = 0;
for (MachineBasicBlock::const_succ_iterator
I = MBB->succ_begin(), E = MBB->succ_end(); I != E; ++I) {
const MachineBasicBlock *Succ = *I;
// Don't consider back-edges.
if (CurLoop && Succ == CurLoop->getHeader())
continue;
// Don't consider successors exiting CurLoop.
if (isExitingLoop(CurLoop, getLoopFor(Succ)))
continue;
const MachineTraceMetrics::TraceBlockInfo *SuccTBI =
getHeightResources(Succ);
// 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)
Best = Succ, BestHeight = Height;
}
return Best;
}
// Get an Ensemble sub-class for the requested trace strategy.
MachineTraceMetrics::Ensemble *
MachineTraceMetrics::getEnsemble(MachineTraceMetrics::Strategy strategy) {
assert(strategy < TS_NumStrategies && "Invalid trace strategy enum");
Ensemble *&E = Ensembles[strategy];
if (E)
return E;
// Allocate new Ensemble on demand.
switch (strategy) {
case TS_MinInstrCount: return (E = new MinInstrCountEnsemble(this));
default: llvm_unreachable("Invalid trace strategy enum");
}
}
void MachineTraceMetrics::invalidate(const MachineBasicBlock *MBB) {
DEBUG(dbgs() << "Invalidate traces through BB#" << MBB->getNumber() << '\n');
BlockInfo[MBB->getNumber()].invalidate();
for (unsigned i = 0; i != TS_NumStrategies; ++i)
if (Ensembles[i])
Ensembles[i]->invalidate(MBB);
}
void MachineTraceMetrics::verifyAnalysis() const {
if (!MF)
return;
#ifndef NDEBUG
assert(BlockInfo.size() == MF->getNumBlockIDs() && "Outdated BlockInfo size");
for (unsigned i = 0; i != TS_NumStrategies; ++i)
if (Ensembles[i])
Ensembles[i]->verify();
#endif
}
//===----------------------------------------------------------------------===//
// Trace building
//===----------------------------------------------------------------------===//
//
// Traces are built by two CFG traversals. To avoid recomputing too much, use a
// set abstraction that confines the search to the current loop, and doesn't
// revisit blocks.
namespace {
struct LoopBounds {
MutableArrayRef<MachineTraceMetrics::TraceBlockInfo> Blocks;
SmallPtrSet<const MachineBasicBlock*, 8> Visited;
const MachineLoopInfo *Loops;
bool Downward;
LoopBounds(MutableArrayRef<MachineTraceMetrics::TraceBlockInfo> blocks,
const MachineLoopInfo *loops)
: Blocks(blocks), Loops(loops), Downward(false) {}
};
}
// Specialize po_iterator_storage in order to prune the post-order traversal so
// it is limited to the current loop and doesn't traverse the loop back edges.
namespace llvm {
template<>
class po_iterator_storage<LoopBounds, true> {
LoopBounds &LB;
public:
po_iterator_storage(LoopBounds &lb) : LB(lb) {}
void finishPostorder(const MachineBasicBlock*) {}
bool insertEdge(const MachineBasicBlock *From, const MachineBasicBlock *To) {
// Skip already visited To blocks.
MachineTraceMetrics::TraceBlockInfo &TBI = LB.Blocks[To->getNumber()];
if (LB.Downward ? TBI.hasValidHeight() : TBI.hasValidDepth())
return false;
// From is null once when To is the trace center block.
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);
}
};
}
/// Compute the trace through MBB.
void MachineTraceMetrics::Ensemble::computeTrace(const MachineBasicBlock *MBB) {
DEBUG(dbgs() << "Computing " << getName() << " trace through BB#"
<< MBB->getNumber() << '\n');
// Set up loop bounds for the backwards post-order traversal.
LoopBounds Bounds(BlockInfo, MTM.Loops);
// 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) {
DEBUG(dbgs() << " pred for BB#" << I->getNumber() << ": ");
TraceBlockInfo &TBI = BlockInfo[I->getNumber()];
// All the predecessors have been visited, pick the preferred one.
TBI.Pred = pickTracePred(*I);
DEBUG({
if (TBI.Pred)
dbgs() << "BB#" << TBI.Pred->getNumber() << '\n';
else
dbgs() << "null\n";
});
// The trace leading to I is now known, compute the depth resources.
computeDepthResources(*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) {
DEBUG(dbgs() << " succ for BB#" << I->getNumber() << ": ");
TraceBlockInfo &TBI = BlockInfo[I->getNumber()];
// All the successors have been visited, pick the preferred one.
TBI.Succ = pickTraceSucc(*I);
DEBUG({
if (TBI.Succ)
dbgs() << "BB#" << TBI.Succ->getNumber() << '\n';
else
dbgs() << "null\n";
});
// The trace leaving I is now known, compute the height resources.
computeHeightResources(*I);
}
}
/// Invalidate traces through BadMBB.
void
MachineTraceMetrics::Ensemble::invalidate(const MachineBasicBlock *BadMBB) {
SmallVector<const MachineBasicBlock*, 16> WorkList;
TraceBlockInfo &BadTBI = BlockInfo[BadMBB->getNumber()];
// Invalidate height resources of blocks above MBB.
if (BadTBI.hasValidHeight()) {
BadTBI.invalidateHeight();
WorkList.push_back(BadMBB);
do {
const MachineBasicBlock *MBB = WorkList.pop_back_val();
DEBUG(dbgs() << "Invalidate BB#" << MBB->getNumber() << ' ' << getName()
<< " height.\n");
// Find any MBB predecessors that have MBB as their preferred successor.
// They are the only ones that need to be invalidated.
for (MachineBasicBlock::const_pred_iterator
I = MBB->pred_begin(), E = MBB->pred_end(); I != E; ++I) {
TraceBlockInfo &TBI = BlockInfo[(*I)->getNumber()];
if (!TBI.hasValidHeight())
continue;
if (TBI.Succ == MBB) {
TBI.invalidateHeight();
WorkList.push_back(*I);
continue;
}
// Verify that TBI.Succ is actually a *I successor.
assert((!TBI.Succ || (*I)->isSuccessor(TBI.Succ)) && "CFG changed");
}
} while (!WorkList.empty());
}
// Invalidate depth resources of blocks below MBB.
if (BadTBI.hasValidDepth()) {
BadTBI.invalidateDepth();
WorkList.push_back(BadMBB);
do {
const MachineBasicBlock *MBB = WorkList.pop_back_val();
DEBUG(dbgs() << "Invalidate BB#" << MBB->getNumber() << ' ' << getName()
<< " depth.\n");
// Find any MBB successors that have MBB as their preferred predecessor.
// They are the only ones that need to be invalidated.
for (MachineBasicBlock::const_succ_iterator
I = MBB->succ_begin(), E = MBB->succ_end(); I != E; ++I) {
TraceBlockInfo &TBI = BlockInfo[(*I)->getNumber()];
if (!TBI.hasValidDepth())
continue;
if (TBI.Pred == MBB) {
TBI.invalidateDepth();
WorkList.push_back(*I);
continue;
}
// Verify that TBI.Pred is actually a *I predecessor.
assert((!TBI.Pred || (*I)->isPredecessor(TBI.Pred)) && "CFG changed");
}
} while (!WorkList.empty());
}
// Clear any per-instruction data. We only have to do this for BadMBB itself
// because the instructions in that block may change. Other blocks may be
// invalidated, but their instructions will stay the same, so there is no
// need to erase the Cycle entries. They will be overwritten when we
// recompute.
for (const auto &I : *BadMBB)
Cycles.erase(&I);
}
void MachineTraceMetrics::Ensemble::verify() const {
#ifndef NDEBUG
assert(BlockInfo.size() == MTM.MF->getNumBlockIDs() &&
"Outdated BlockInfo size");
for (unsigned Num = 0, e = BlockInfo.size(); Num != e; ++Num) {
const TraceBlockInfo &TBI = BlockInfo[Num];
if (TBI.hasValidDepth() && TBI.Pred) {
const MachineBasicBlock *MBB = MTM.MF->getBlockNumbered(Num);
assert(MBB->isPredecessor(TBI.Pred) && "CFG doesn't match trace");
assert(BlockInfo[TBI.Pred->getNumber()].hasValidDepth() &&
"Trace is broken, depth should have been invalidated.");
const MachineLoop *Loop = getLoopFor(MBB);
assert(!(Loop && MBB == Loop->getHeader()) && "Trace contains backedge");
}
if (TBI.hasValidHeight() && TBI.Succ) {
const MachineBasicBlock *MBB = MTM.MF->getBlockNumbered(Num);
assert(MBB->isSuccessor(TBI.Succ) && "CFG doesn't match trace");
assert(BlockInfo[TBI.Succ->getNumber()].hasValidHeight() &&
"Trace is broken, height should have been invalidated.");
const MachineLoop *Loop = getLoopFor(MBB);
const MachineLoop *SuccLoop = getLoopFor(TBI.Succ);
assert(!(Loop && Loop == SuccLoop && TBI.Succ == Loop->getHeader()) &&
"Trace contains backedge");
}
}
#endif
}
//===----------------------------------------------------------------------===//
// Data Dependencies
//===----------------------------------------------------------------------===//
//
// Compute the depth and height of each instruction based on data dependencies
// and instruction latencies. These cycle numbers assume that the CPU can issue
// an infinite number of instructions per cycle as long as their dependencies
// are ready.
// A data dependency is represented as a defining MI and operand numbers on the
// defining and using MI.
namespace {
struct DataDep {
const MachineInstr *DefMI;
unsigned DefOp;
unsigned UseOp;
DataDep(const MachineInstr *DefMI, unsigned DefOp, unsigned UseOp)
: DefMI(DefMI), DefOp(DefOp), UseOp(UseOp) {}
/// Create a DataDep from an SSA form virtual register.
DataDep(const MachineRegisterInfo *MRI, unsigned VirtReg, unsigned UseOp)
: UseOp(UseOp) {
assert(TargetRegisterInfo::isVirtualRegister(VirtReg));
MachineRegisterInfo::def_iterator DefI = MRI->def_begin(VirtReg);
assert(!DefI.atEnd() && "Register has no defs");
DefMI = DefI->getParent();
DefOp = DefI.getOperandNo();
assert((++DefI).atEnd() && "Register has multiple defs");
}
};
}
// Get the input data dependencies that must be ready before UseMI can issue.
// Return true if UseMI has any physreg operands.
static bool getDataDeps(const MachineInstr *UseMI,
SmallVectorImpl<DataDep> &Deps,
const MachineRegisterInfo *MRI) {
bool HasPhysRegs = false;
for (ConstMIOperands MO(UseMI); MO.isValid(); ++MO) {
if (!MO->isReg())
continue;
unsigned Reg = MO->getReg();
if (!Reg)
continue;
if (TargetRegisterInfo::isPhysicalRegister(Reg)) {
HasPhysRegs = true;
continue;
}
// Collect virtual register reads.
if (MO->readsReg())
Deps.push_back(DataDep(MRI, Reg, MO.getOperandNo()));
}
return HasPhysRegs;
}
// Get the input data dependencies of a PHI instruction, using Pred as the
// preferred predecessor.
// This will add at most one dependency to Deps.
static void getPHIDeps(const MachineInstr *UseMI,
SmallVectorImpl<DataDep> &Deps,
const MachineBasicBlock *Pred,
const MachineRegisterInfo *MRI) {
// No predecessor at the beginning of a trace. Ignore dependencies.
if (!Pred)
return;
assert(UseMI->isPHI() && UseMI->getNumOperands() % 2 && "Bad PHI");
for (unsigned i = 1; i != UseMI->getNumOperands(); i += 2) {
if (UseMI->getOperand(i + 1).getMBB() == Pred) {
unsigned Reg = UseMI->getOperand(i).getReg();
Deps.push_back(DataDep(MRI, Reg, i));
return;
}
}
}
// 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 Cycle;
const MachineInstr *MI;
unsigned Op;
unsigned getSparseSetIndex() const { return RegUnit; }
LiveRegUnit(unsigned RU) : RegUnit(RU), Cycle(0), MI(nullptr), Op(0) {}
};
}
// Identify physreg dependencies for UseMI, and update the live regunit
// tracking set when scanning instructions downwards.
static void updatePhysDepsDownwards(const MachineInstr *UseMI,
SmallVectorImpl<DataDep> &Deps,
SparseSet<LiveRegUnit> &RegUnits,
const TargetRegisterInfo *TRI) {
SmallVector<unsigned, 8> Kills;
SmallVector<unsigned, 8> LiveDefOps;
for (ConstMIOperands MO(UseMI); MO.isValid(); ++MO) {
if (!MO->isReg())
continue;
unsigned Reg = MO->getReg();
if (!TargetRegisterInfo::isPhysicalRegister(Reg))
continue;
// Track live defs and kills for updating RegUnits.
if (MO->isDef()) {
if (MO->isDead())
Kills.push_back(Reg);
else
LiveDefOps.push_back(MO.getOperandNo());
} else if (MO->isKill())
Kills.push_back(Reg);
// Identify dependencies.
if (!MO->readsReg())
continue;
for (MCRegUnitIterator Units(Reg, TRI); Units.isValid(); ++Units) {
SparseSet<LiveRegUnit>::iterator I = RegUnits.find(*Units);
if (I == RegUnits.end())
continue;
Deps.push_back(DataDep(I->MI, I->Op, MO.getOperandNo()));
break;
}
}
// Update RegUnits to reflect live registers after UseMI.
// First kills.
for (unsigned i = 0, e = Kills.size(); i != e; ++i)
for (MCRegUnitIterator Units(Kills[i], TRI); Units.isValid(); ++Units)
RegUnits.erase(*Units);
// Second, live defs.
for (unsigned i = 0, e = LiveDefOps.size(); i != e; ++i) {
unsigned DefOp = LiveDefOps[i];
for (MCRegUnitIterator Units(UseMI->getOperand(DefOp).getReg(), TRI);
Units.isValid(); ++Units) {
LiveRegUnit &LRU = RegUnits[*Units];
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.isUsefulDominator(TBI))
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.
void MachineTraceMetrics::Ensemble::
computeInstrDepths(const MachineBasicBlock *MBB) {
// The top of the trace may already be computed, and HasValidInstrDepths
// implies Head->HasValidInstrDepths, so we only need to start from the first
// block in the trace that needs to be recomputed.
SmallVector<const MachineBasicBlock*, 8> Stack;
do {
TraceBlockInfo &TBI = BlockInfo[MBB->getNumber()];
assert(TBI.hasValidDepth() && "Incomplete trace");
if (TBI.HasValidInstrDepths)
break;
Stack.push_back(MBB);
MBB = TBI.Pred;
} while (MBB);
// FIXME: If MBB is non-null at this point, it is the last pre-computed block
// in the trace. We should track any live-out physregs that were defined in
// the trace. This is quite rare in SSA form, typically created by CSE
// hoisting a compare.
SparseSet<LiveRegUnit> RegUnits;
RegUnits.setUniverse(MTM.TRI->getNumRegUnits());
// Go through trace blocks in top-down order, stopping after the center block.
SmallVector<DataDep, 8> Deps;
while (!Stack.empty()) {
MBB = Stack.pop_back_val();
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);
for (const auto &UseMI : *MBB) {
// Collect all data dependencies.
Deps.clear();
if (UseMI.isPHI())
getPHIDeps(&UseMI, Deps, TBI.Pred, MTM.MRI);
else if (getDataDeps(&UseMI, Deps, MTM.MRI))
updatePhysDepsDownwards(&UseMI, Deps, RegUnits, MTM.TRI);
// Filter and process dependencies, computing the earliest issue cycle.
unsigned Cycle = 0;
for (unsigned i = 0, e = Deps.size(); i != e; ++i) {
const DataDep &Dep = Deps[i];
const TraceBlockInfo&DepTBI =
BlockInfo[Dep.DefMI->getParent()->getNumber()];
// Ignore dependencies from outside the current trace.
if (!DepTBI.isUsefulDominator(TBI))
continue;
assert(DepTBI.HasValidInstrDepths && "Inconsistent dependency");
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.SchedModel
.computeOperandLatency(Dep.DefMI, Dep.DefOp, &UseMI, Dep.UseOp);
Cycle = std::max(Cycle, DepCycle);
}
// Remember the instruction depth.
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);
}
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);
// Update Heights[DefMI] to be the maximum height seen.
MIHeightMap::iterator I;
bool New;
std::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 the virtual register defined by DefMI:DefOp 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, unsigned DefOp,
ArrayRef<const MachineBasicBlock*> Trace) {
assert(!Trace.empty() && "Trace should contain at least one block");
unsigned Reg = DefMI->getOperand(DefOp).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;
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
// 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 (const auto &PHI : *Succ) {
if (!PHI.isPHI())
break;
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, Deps.front().DefOp, 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, Deps[i].DefOp, 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
MachineTraceMetrics::Ensemble::getTrace(const MachineBasicBlock *MBB) {
// 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);
return DepCycle;
}
/// When bottom is set include instructions in current block in estimate.
unsigned MachineTraceMetrics::Trace::getResourceDepth(bool Bottom) const {
// 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);
/// All instructions before current block
unsigned Instrs = TBI.InstrDepth;
// plus instructions in current block
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 std::max(Instrs, PRMax);
}
unsigned MachineTraceMetrics::Trace::getResourceLength(
ArrayRef<const MachineBasicBlock *> Extrablocks,
ArrayRef<const MCSchedClassDesc *> ExtraInstrs,
ArrayRef<const MCSchedClassDesc *> RemoveInstrs) 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;
// Capture computing cycles from extra instructions
auto extraCycles = [this](ArrayRef<const MCSchedClassDesc *> Instrs,
unsigned ResourceIdx)
->unsigned {
unsigned Cycles = 0;
for (unsigned I = 0; I != Instrs.size(); ++I) {
const MCSchedClassDesc *SC = Instrs[I];
if (!SC->isValid())
continue;
for (TargetSchedModel::ProcResIter
PI = TE.MTM.SchedModel.getWriteProcResBegin(SC),
PE = TE.MTM.SchedModel.getWriteProcResEnd(SC);
PI != PE; ++PI) {
if (PI->ProcResourceIdx != ResourceIdx)
continue;
Cycles +=
(PI->Cycles * TE.MTM.SchedModel.getResourceFactor(ResourceIdx));
}
}
return Cycles;
};
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];
PRCycles += extraCycles(ExtraInstrs, K);
PRCycles -= extraCycles(RemoveInstrs, K);
PRMax = std::max(PRMax, PRCycles);
}
// Convert to cycle count.
PRMax = TE.MTM.getCycles(PRMax);
// Instrs: #instructions in current trace outside current block.
unsigned Instrs = TBI.InstrDepth + TBI.InstrHeight;
// Add instruction count from the extra blocks.
for (unsigned i = 0, e = Extrablocks.size(); i != e; ++i)
Instrs += TE.MTM.getResources(Extrablocks[i])->InstrCount;
Instrs += ExtraInstrs.size();
Instrs -= RemoveInstrs.size();
if (unsigned IW = TE.MTM.SchedModel.getIssueWidth())
Instrs /= IW;
// Assume issue width 1 without a schedule model.
return std::max(Instrs, PRMax);
}
bool MachineTraceMetrics::Trace::isDepInTrace(const MachineInstr *DefMI,
const MachineInstr *UseMI) const {
if (DefMI->getParent() == UseMI->getParent())
return true;
const TraceBlockInfo &DepTBI = TE.BlockInfo[DefMI->getParent()->getNumber()];
const TraceBlockInfo &TBI = TE.BlockInfo[UseMI->getParent()->getNumber()];
return DepTBI.isUsefulDominator(TBI);
}
void MachineTraceMetrics::Ensemble::print(raw_ostream &OS) const {
OS << getName() << " ensemble:\n";
for (unsigned i = 0, e = BlockInfo.size(); i != e; ++i) {
OS << " BB#" << i << '\t';
BlockInfo[i].print(OS);
OS << '\n';
}
}
void MachineTraceMetrics::TraceBlockInfo::print(raw_ostream &OS) const {
if (hasValidDepth()) {
OS << "depth=" << InstrDepth;
if (Pred)
OS << " pred=BB#" << Pred->getNumber();
else
OS << " pred=null";
OS << " head=BB#" << Head;
if (HasValidInstrDepths)
OS << " +instrs";
} else
OS << "depth invalid";
OS << ", ";
if (hasValidHeight()) {
OS << "height=" << InstrHeight;
if (Succ)
OS << " succ=BB#" << Succ->getNumber();
else
OS << " succ=null";
OS << " tail=BB#" << Tail;
if (HasValidInstrHeights)
OS << " +instrs";
} else
OS << "height invalid";
if (HasValidInstrDepths && HasValidInstrHeights)
OS << ", crit=" << CriticalPath;
}
void MachineTraceMetrics::Trace::print(raw_ostream &OS) const {
unsigned MBBNum = &TBI - &TE.BlockInfo[0];
OS << TE.getName() << " trace BB#" << TBI.Head << " --> BB#" << MBBNum
<< " --> 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;
while (Block->hasValidDepth() && Block->Pred) {
unsigned Num = Block->Pred->getNumber();
OS << " <- BB#" << Num;
Block = &TE.BlockInfo[Num];
}
Block = &TBI;
OS << "\n ";
while (Block->hasValidHeight() && Block->Succ) {
unsigned Num = Block->Succ->getNumber();
OS << " -> BB#" << Num;
Block = &TE.BlockInfo[Num];
}
OS << '\n';
}