Use BranchProbability instead of floating points in IfConverter.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134858 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/IfConversion.cpp b/lib/CodeGen/IfConversion.cpp
index 8cf68d6..6cb2277 100644
--- a/lib/CodeGen/IfConversion.cpp
+++ b/lib/CodeGen/IfConversion.cpp
@@ -23,6 +23,7 @@
#include "llvm/Target/TargetLowering.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetRegisterInfo.h"
+#include "llvm/Support/BranchProbability.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
@@ -173,10 +174,10 @@
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);
@@ -203,19 +204,19 @@
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.
@@ -450,7 +451,7 @@
/// 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;
@@ -461,7 +462,7 @@
if (TrueBBI.BB->pred_size() > 1) {
if (TrueBBI.CannotBeCopied ||
!TII->isProfitableToDupForIfCvt(*TrueBBI.BB, TrueBBI.NonPredSize,
- Prediction, Confidence))
+ Prediction))
return false;
Dups = TrueBBI.NonPredSize;
}
@@ -477,7 +478,7 @@
/// 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;
@@ -499,8 +500,7 @@
++Size;
}
}
- if (!TII->isProfitableToDupForIfCvt(*TrueBBI.BB, Size,
- Prediction, Confidence))
+ if (!TII->isProfitableToDupForIfCvt(*TrueBBI.BB, Size, Prediction))
return false;
Dups = Size;
}
@@ -796,21 +796,20 @@
// - backedge -> 90% taken
// - early exit -> 20% taken
// - branch predictor confidence -> 90%
- float Prediction = 0.5f;
- float Confidence = 0.9f;
+ BranchProbability Prediction(5, 10);
MachineLoop *Loop = MLI->getLoopFor(BB);
if (Loop) {
if (TrueBBI.BB == Loop->getHeader())
- Prediction = 0.9f;
+ Prediction = BranchProbability(9, 10);
else if (FalseBBI.BB == Loop->getHeader())
- Prediction = 0.1f;
+ Prediction = BranchProbability(1, 10);
MachineLoop *TrueLoop = MLI->getLoopFor(TrueBBI.BB);
MachineLoop *FalseLoop = MLI->getLoopFor(FalseBBI.BB);
if (!TrueLoop || TrueLoop->getParentLoop() == Loop)
- Prediction = 0.2f;
+ Prediction = BranchProbability(2, 10);
else if (!FalseLoop || FalseLoop->getParentLoop() == Loop)
- Prediction = 0.8f;
+ Prediction = BranchProbability(8, 10);
}
if (CanRevCond && ValidDiamond(TrueBBI, FalseBBI, Dups, Dups2) &&
@@ -818,7 +817,7 @@
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:
@@ -834,9 +833,9 @@
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
@@ -849,17 +848,17 @@
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
@@ -875,29 +874,29 @@
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;