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//===-------- BlockFrequency.h - Block Frequency Wrapper --------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements Block Frequency class.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_SUPPORT_BLOCKFREQUENCY_H
#define LLVM_SUPPORT_BLOCKFREQUENCY_H
#include "llvm/Support/DataTypes.h"
namespace llvm {
class raw_ostream;
class BranchProbability;
// This class represents Block Frequency as a 64-bit value.
class BlockFrequency {
uint64_t Frequency;
static const int64_t ENTRY_FREQ = 1 << 14;
/// \brief Scale the given BlockFrequency by N/D. Return the remainder from
/// the division by D. Upon overflow, the routine will saturate and
/// additionally will return the remainder set to D.
uint32_t scale(uint32_t N, uint32_t D);
public:
BlockFrequency(uint64_t Freq = 0) : Frequency(Freq) { }
/// \brief Returns the frequency of the entry block of the function.
static uint64_t getEntryFrequency() { return ENTRY_FREQ; }
/// \brief Returns the maximum possible frequency, the saturation value.
static uint64_t getMaxFrequency() { return -1ULL; }
/// \brief Returns the frequency as a fixpoint number scaled by the entry
/// frequency.
uint64_t getFrequency() const { return Frequency; }
/// \brief Multiplies with a branch probability. The computation will never
/// overflow.
BlockFrequency &operator*=(const BranchProbability &Prob);
const BlockFrequency operator*(const BranchProbability &Prob) const;
/// \brief Divide by a non-zero branch probability using saturating
/// arithmetic.
BlockFrequency &operator/=(const BranchProbability &Prob);
BlockFrequency operator/(const BranchProbability &Prob) const;
/// \brief Adds another block frequency using saturating arithmetic.
BlockFrequency &operator+=(const BlockFrequency &Freq);
const BlockFrequency operator+(const BlockFrequency &Freq) const;
/// \brief Scale the given BlockFrequency by N/D. Return the remainder from
/// the division by D. Upon overflow, the routine will saturate.
uint32_t scale(const BranchProbability &Prob);
bool operator<(const BlockFrequency &RHS) const {
return Frequency < RHS.Frequency;
}
bool operator<=(const BlockFrequency &RHS) const {
return Frequency <= RHS.Frequency;
}
bool operator>(const BlockFrequency &RHS) const {
return Frequency > RHS.Frequency;
}
bool operator>=(const BlockFrequency &RHS) const {
return Frequency >= RHS.Frequency;
}
void print(raw_ostream &OS) const;
};
raw_ostream &operator<<(raw_ostream &OS, const BlockFrequency &Freq);
}
#endif
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