#include "llvm/Function.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
+#include "llvm/CodeGen/MachineBranchProbabilityInfo.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
-#include "llvm/CodeGen/MachineLoopInfo.h"
#include "llvm/MC/MCInstrItineraries.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetLowering.h"
const TargetInstrInfo *TII;
const TargetRegisterInfo *TRI;
const InstrItineraryData *InstrItins;
- const MachineLoopInfo *MLI;
+ const MachineBranchProbabilityInfo *MBPI;
+
bool MadeChange;
int FnNum;
public:
IfConverter() : MachineFunctionPass(ID), FnNum(-1) {
initializeIfConverterPass(*PassRegistry::getPassRegistry());
}
-
+
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
- AU.addRequired<MachineLoopInfo>();
+ AU.addRequired<MachineBranchProbabilityInfo>();
MachineFunctionPass::getAnalysisUsage(AU);
}
private:
bool ReverseBranchCondition(BBInfo &BBI);
bool ValidSimple(BBInfo &TrueBBI, unsigned &Dups,
- float Prediction, float Confidence) const;
+ const BranchProbability &Prediction) const;
bool ValidTriangle(BBInfo &TrueBBI, BBInfo &FalseBBI,
bool FalseBranch, unsigned &Dups,
- float Prediction, float Confidence) const;
+ const BranchProbability &Prediction) const;
bool ValidDiamond(BBInfo &TrueBBI, BBInfo &FalseBBI,
unsigned &Dups1, unsigned &Dups2) const;
void ScanInstructions(BBInfo &BBI);
bool MeetIfcvtSizeLimit(MachineBasicBlock &BB,
unsigned Cycle, unsigned Extra,
- float Prediction, float Confidence) const {
+ const BranchProbability &Prediction) const {
return Cycle > 0 && TII->isProfitableToIfCvt(BB, Cycle, Extra,
- Prediction, Confidence);
+ Prediction);
}
bool MeetIfcvtSizeLimit(MachineBasicBlock &TBB,
unsigned TCycle, unsigned TExtra,
MachineBasicBlock &FBB,
unsigned FCycle, unsigned FExtra,
- float Prediction, float Confidence) const {
+ const BranchProbability &Prediction) const {
return TCycle > 0 && FCycle > 0 &&
TII->isProfitableToIfCvt(TBB, TCycle, TExtra, FBB, FCycle, FExtra,
- Prediction, Confidence);
+ Prediction);
}
// blockAlwaysFallThrough - Block ends without a terminator.
}
INITIALIZE_PASS_BEGIN(IfConverter, "if-converter", "If Converter", false, false)
-INITIALIZE_PASS_DEPENDENCY(MachineLoopInfo)
+INITIALIZE_PASS_DEPENDENCY(MachineBranchProbabilityInfo)
INITIALIZE_PASS_END(IfConverter, "if-converter", "If Converter", false, false)
FunctionPass *llvm::createIfConverterPass() { return new IfConverter(); }
TLI = MF.getTarget().getTargetLowering();
TII = MF.getTarget().getInstrInfo();
TRI = MF.getTarget().getRegisterInfo();
- MLI = &getAnalysis<MachineLoopInfo>();
+ MBPI = &getAnalysis<MachineBranchProbabilityInfo>();
InstrItins = MF.getTarget().getInstrItineraryData();
if (!TII) return false;
/// number of instructions that the ifcvt would need to duplicate if performed
/// in Dups.
bool IfConverter::ValidSimple(BBInfo &TrueBBI, unsigned &Dups,
- float Prediction, float Confidence) const {
+ const BranchProbability &Prediction) const {
Dups = 0;
if (TrueBBI.IsBeingAnalyzed || TrueBBI.IsDone)
return false;
if (TrueBBI.BB->pred_size() > 1) {
if (TrueBBI.CannotBeCopied ||
!TII->isProfitableToDupForIfCvt(*TrueBBI.BB, TrueBBI.NonPredSize,
- Prediction, Confidence))
+ Prediction))
return false;
Dups = TrueBBI.NonPredSize;
}
/// if performed in 'Dups'.
bool IfConverter::ValidTriangle(BBInfo &TrueBBI, BBInfo &FalseBBI,
bool FalseBranch, unsigned &Dups,
- float Prediction, float Confidence) const {
+ const BranchProbability &Prediction) const {
Dups = 0;
if (TrueBBI.IsBeingAnalyzed || TrueBBI.IsDone)
return false;
++Size;
}
}
- if (!TII->isProfitableToDupForIfCvt(*TrueBBI.BB, Size,
- Prediction, Confidence))
+ if (!TII->isProfitableToDupForIfCvt(*TrueBBI.BB, Size, Prediction))
return false;
Dups = Size;
}
// blocks, move the end iterators up past any branch instructions.
while (TIE != TIB) {
--TIE;
- if (!TIE->getDesc().isBranch())
+ if (!TIE->isBranch())
break;
}
while (FIE != FIB) {
--FIE;
- if (!FIE->getDesc().isBranch())
+ if (!FIE->isBranch())
break;
}
if (I->isDebugValue())
continue;
- const MCInstrDesc &MCID = I->getDesc();
- if (MCID.isNotDuplicable())
+ if (I->isNotDuplicable())
BBI.CannotBeCopied = true;
bool isPredicated = TII->isPredicated(I);
- bool isCondBr = BBI.IsBrAnalyzable && MCID.isConditionalBranch();
+ bool isCondBr = BBI.IsBrAnalyzable && I->isConditionalBranch();
if (!isCondBr) {
if (!isPredicated) {
bool TNeedSub = TrueBBI.Predicate.size() > 0;
bool FNeedSub = FalseBBI.Predicate.size() > 0;
bool Enqueued = false;
-
- // Try to predict the branch, using loop info to guide us.
- // General heuristics are:
- // - backedge -> 90% taken
- // - early exit -> 20% taken
- // - branch predictor confidence -> 90%
- float Prediction = 0.5f;
- float Confidence = 0.9f;
- MachineLoop *Loop = MLI->getLoopFor(BB);
- if (Loop) {
- if (TrueBBI.BB == Loop->getHeader())
- Prediction = 0.9f;
- else if (FalseBBI.BB == Loop->getHeader())
- Prediction = 0.1f;
-
- MachineLoop *TrueLoop = MLI->getLoopFor(TrueBBI.BB);
- MachineLoop *FalseLoop = MLI->getLoopFor(FalseBBI.BB);
- if (!TrueLoop || TrueLoop->getParentLoop() == Loop)
- Prediction = 0.2f;
- else if (!FalseLoop || FalseLoop->getParentLoop() == Loop)
- Prediction = 0.8f;
- }
-
+
+ BranchProbability Prediction = MBPI->getEdgeProbability(BB, TrueBBI.BB);
+
if (CanRevCond && ValidDiamond(TrueBBI, FalseBBI, Dups, Dups2) &&
MeetIfcvtSizeLimit(*TrueBBI.BB, (TrueBBI.NonPredSize - (Dups + Dups2) +
TrueBBI.ExtraCost), TrueBBI.ExtraCost2,
*FalseBBI.BB, (FalseBBI.NonPredSize - (Dups + Dups2) +
FalseBBI.ExtraCost),FalseBBI.ExtraCost2,
- Prediction, Confidence) &&
+ Prediction) &&
FeasibilityAnalysis(TrueBBI, BBI.BrCond) &&
FeasibilityAnalysis(FalseBBI, RevCond)) {
// Diamond:
Enqueued = true;
}
- if (ValidTriangle(TrueBBI, FalseBBI, false, Dups, Prediction, Confidence) &&
+ if (ValidTriangle(TrueBBI, FalseBBI, false, Dups, Prediction) &&
MeetIfcvtSizeLimit(*TrueBBI.BB, TrueBBI.NonPredSize + TrueBBI.ExtraCost,
- TrueBBI.ExtraCost2, Prediction, Confidence) &&
+ TrueBBI.ExtraCost2, Prediction) &&
FeasibilityAnalysis(TrueBBI, BBI.BrCond, true)) {
// Triangle:
// EBB
Enqueued = true;
}
- if (ValidTriangle(TrueBBI, FalseBBI, true, Dups, Prediction, Confidence) &&
+ if (ValidTriangle(TrueBBI, FalseBBI, true, Dups, Prediction) &&
MeetIfcvtSizeLimit(*TrueBBI.BB, TrueBBI.NonPredSize + TrueBBI.ExtraCost,
- TrueBBI.ExtraCost2, Prediction, Confidence) &&
+ TrueBBI.ExtraCost2, Prediction) &&
FeasibilityAnalysis(TrueBBI, BBI.BrCond, true, true)) {
Tokens.push_back(new IfcvtToken(BBI, ICTriangleRev, TNeedSub, Dups));
Enqueued = true;
}
- if (ValidSimple(TrueBBI, Dups, Prediction, Confidence) &&
+ if (ValidSimple(TrueBBI, Dups, Prediction) &&
MeetIfcvtSizeLimit(*TrueBBI.BB, TrueBBI.NonPredSize + TrueBBI.ExtraCost,
- TrueBBI.ExtraCost2, Prediction, Confidence) &&
+ TrueBBI.ExtraCost2, Prediction) &&
FeasibilityAnalysis(TrueBBI, BBI.BrCond)) {
// Simple (split, no rejoin):
// EBB
if (CanRevCond) {
// Try the other path...
if (ValidTriangle(FalseBBI, TrueBBI, false, Dups,
- 1.0-Prediction, Confidence) &&
+ Prediction.getCompl()) &&
MeetIfcvtSizeLimit(*FalseBBI.BB,
FalseBBI.NonPredSize + FalseBBI.ExtraCost,
- FalseBBI.ExtraCost2, 1.0-Prediction, Confidence) &&
+ FalseBBI.ExtraCost2, Prediction.getCompl()) &&
FeasibilityAnalysis(FalseBBI, RevCond, true)) {
Tokens.push_back(new IfcvtToken(BBI, ICTriangleFalse, FNeedSub, Dups));
Enqueued = true;
}
if (ValidTriangle(FalseBBI, TrueBBI, true, Dups,
- 1.0-Prediction, Confidence) &&
+ Prediction.getCompl()) &&
MeetIfcvtSizeLimit(*FalseBBI.BB,
FalseBBI.NonPredSize + FalseBBI.ExtraCost,
- FalseBBI.ExtraCost2, 1.0-Prediction, Confidence) &&
+ FalseBBI.ExtraCost2, Prediction.getCompl()) &&
FeasibilityAnalysis(FalseBBI, RevCond, true, true)) {
Tokens.push_back(new IfcvtToken(BBI, ICTriangleFRev, FNeedSub, Dups));
Enqueued = true;
}
- if (ValidSimple(FalseBBI, Dups, 1.0-Prediction, Confidence) &&
+ if (ValidSimple(FalseBBI, Dups, Prediction.getCompl()) &&
MeetIfcvtSizeLimit(*FalseBBI.BB,
FalseBBI.NonPredSize + FalseBBI.ExtraCost,
- FalseBBI.ExtraCost2, 1.0-Prediction, Confidence) &&
+ FalseBBI.ExtraCost2, Prediction.getCompl()) &&
FeasibilityAnalysis(FalseBBI, RevCond)) {
Tokens.push_back(new IfcvtToken(BBI, ICSimpleFalse, FNeedSub, Dups));
Enqueued = true;
// fold the tail block in as well. Otherwise, unless it falls through to the
// tail, add a unconditional branch to it.
if (TailBB) {
- BBInfo TailBBI = BBAnalysis[TailBB->getNumber()];
+ BBInfo &TailBBI = BBAnalysis[TailBB->getNumber()];
bool CanMergeTail = !TailBBI.HasFallThrough;
// There may still be a fall-through edge from BBI1 or BBI2 to TailBB;
// check if there are any other predecessors besides those.
for (MachineBasicBlock::iterator I = FromBBI.BB->begin(),
E = FromBBI.BB->end(); I != E; ++I) {
- const MCInstrDesc &MCID = I->getDesc();
// Do not copy the end of the block branches.
- if (IgnoreBr && MCID.isBranch())
+ if (IgnoreBr && I->isBranch())
break;
MachineInstr *MI = MF.CloneMachineInstr(I);