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/Target/ARM/ARMBaseInstrInfo.cpp b/lib/Target/ARM/ARMBaseInstrInfo.cpp
index 32e9372..b1aa7ce 100644
--- a/lib/Target/ARM/ARMBaseInstrInfo.cpp
+++ b/lib/Target/ARM/ARMBaseInstrInfo.cpp
@@ -30,6 +30,7 @@
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/PseudoSourceValue.h"
#include "llvm/MC/MCAsmInfo.h"
+#include "llvm/Support/BranchProbability.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
@@ -1273,20 +1274,20 @@
return false;
}
-bool ARMBaseInstrInfo::isProfitableToIfCvt(MachineBasicBlock &MBB,
- unsigned NumCycles,
- unsigned ExtraPredCycles,
- float Probability,
- float Confidence) const {
+bool ARMBaseInstrInfo::
+isProfitableToIfCvt(MachineBasicBlock &MBB,
+ unsigned NumCycles, unsigned ExtraPredCycles,
+ const BranchProbability &Probability) const {
if (!NumCycles)
return false;
// Attempt to estimate the relative costs of predication versus branching.
- float UnpredCost = Probability * NumCycles;
- UnpredCost += 1.0; // The branch itself
- UnpredCost += (1.0 - Confidence) * Subtarget.getMispredictionPenalty();
+ unsigned UnpredCost = Probability.getNumerator() * NumCycles;
+ UnpredCost /= Probability.getDenominator();
+ UnpredCost += 1; // The branch itself
+ UnpredCost += Subtarget.getMispredictionPenalty() / 10;
- return (float)(NumCycles + ExtraPredCycles) < UnpredCost;
+ return (NumCycles + ExtraPredCycles) <= UnpredCost;
}
bool ARMBaseInstrInfo::
@@ -1294,16 +1295,23 @@
unsigned TCycles, unsigned TExtra,
MachineBasicBlock &FMBB,
unsigned FCycles, unsigned FExtra,
- float Probability, float Confidence) const {
+ const BranchProbability &Probability) const {
if (!TCycles || !FCycles)
return false;
// Attempt to estimate the relative costs of predication versus branching.
- float UnpredCost = Probability * TCycles + (1.0 - Probability) * FCycles;
- UnpredCost += 1.0; // The branch itself
- UnpredCost += (1.0 - Confidence) * Subtarget.getMispredictionPenalty();
+ unsigned TUnpredCost = Probability.getNumerator() * TCycles;
+ TUnpredCost /= Probability.getDenominator();
+
+ uint32_t Comp = Probability.getDenominator() - Probability.getNumerator();
+ unsigned FUnpredCost = Comp * FCycles;
+ FUnpredCost /= Probability.getDenominator();
- return (float)(TCycles + FCycles + TExtra + FExtra) < UnpredCost;
+ unsigned UnpredCost = TUnpredCost + FUnpredCost;
+ UnpredCost += 1; // The branch itself
+ UnpredCost += Subtarget.getMispredictionPenalty() / 10;
+
+ return (TCycles + FCycles + TExtra + FExtra) <= UnpredCost;
}
/// getInstrPredicate - If instruction is predicated, returns its predicate