mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2025-11-04 05:17:07 +00:00
cd52a7a381
Apparently, the style needs to be agreed upon first. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240390 91177308-0d34-0410-b5e6-96231b3b80d8
90 lines
2.5 KiB
C++
90 lines
2.5 KiB
C++
//===- BranchProbability.h - Branch Probability Wrapper ---------*- C++ -*-===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// Definition of BranchProbability shared by IR and Machine Instructions.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef LLVM_SUPPORT_BRANCHPROBABILITY_H
|
|
#define LLVM_SUPPORT_BRANCHPROBABILITY_H
|
|
|
|
#include "llvm/Support/DataTypes.h"
|
|
#include <cassert>
|
|
|
|
namespace llvm {
|
|
|
|
class raw_ostream;
|
|
|
|
// This class represents Branch Probability as a non-negative fraction.
|
|
class BranchProbability {
|
|
// Numerator
|
|
uint32_t N;
|
|
|
|
// Denominator
|
|
uint32_t D;
|
|
|
|
public:
|
|
BranchProbability(uint32_t n, uint32_t d) : N(n), D(d) {
|
|
assert(d > 0 && "Denominator cannot be 0!");
|
|
assert(n <= d && "Probability cannot be bigger than 1!");
|
|
}
|
|
|
|
static BranchProbability getZero() { return BranchProbability(0, 1); }
|
|
static BranchProbability getOne() { return BranchProbability(1, 1); }
|
|
|
|
uint32_t getNumerator() const { return N; }
|
|
uint32_t getDenominator() const { return D; }
|
|
|
|
// Return (1 - Probability).
|
|
BranchProbability getCompl() const {
|
|
return BranchProbability(D - N, D);
|
|
}
|
|
|
|
raw_ostream &print(raw_ostream &OS) const;
|
|
|
|
void dump() const;
|
|
|
|
/// \brief Scale a large integer.
|
|
///
|
|
/// Scales \c Num. Guarantees full precision. Returns the floor of the
|
|
/// result.
|
|
///
|
|
/// \return \c Num times \c this.
|
|
uint64_t scale(uint64_t Num) const;
|
|
|
|
/// \brief Scale a large integer by the inverse.
|
|
///
|
|
/// Scales \c Num by the inverse of \c this. Guarantees full precision.
|
|
/// Returns the floor of the result.
|
|
///
|
|
/// \return \c Num divided by \c this.
|
|
uint64_t scaleByInverse(uint64_t Num) const;
|
|
|
|
bool operator==(BranchProbability RHS) const {
|
|
return (uint64_t)N * RHS.D == (uint64_t)D * RHS.N;
|
|
}
|
|
bool operator!=(BranchProbability RHS) const {
|
|
return !(*this == RHS);
|
|
}
|
|
bool operator<(BranchProbability RHS) const {
|
|
return (uint64_t)N * RHS.D < (uint64_t)D * RHS.N;
|
|
}
|
|
bool operator>(BranchProbability RHS) const { return RHS < *this; }
|
|
bool operator<=(BranchProbability RHS) const { return !(RHS < *this); }
|
|
bool operator>=(BranchProbability RHS) const { return !(*this < RHS); }
|
|
};
|
|
|
|
inline raw_ostream &operator<<(raw_ostream &OS, const BranchProbability &Prob) {
|
|
return Prob.print(OS);
|
|
}
|
|
|
|
}
|
|
|
|
#endif
|