llvm-for-llvmta/include/llvm/Support/BlockFrequency.h

82 lines
2.4 KiB
C++

//===-------- BlockFrequency.h - Block Frequency Wrapper --------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file implements Block Frequency class.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_SUPPORT_BLOCKFREQUENCY_H
#define LLVM_SUPPORT_BLOCKFREQUENCY_H
#include "llvm/Support/BranchProbability.h"
#include "llvm/Support/DataTypes.h"
namespace llvm {
class raw_ostream;
// This class represents Block Frequency as a 64-bit value.
class BlockFrequency {
uint64_t Frequency;
public:
BlockFrequency(uint64_t Freq = 0) : Frequency(Freq) { }
/// Returns the maximum possible frequency, the saturation value.
static uint64_t getMaxFrequency() { return -1ULL; }
/// Returns the frequency as a fixpoint number scaled by the entry
/// frequency.
uint64_t getFrequency() const { return Frequency; }
/// Multiplies with a branch probability. The computation will never
/// overflow.
BlockFrequency &operator*=(BranchProbability Prob);
BlockFrequency operator*(BranchProbability Prob) const;
/// Divide by a non-zero branch probability using saturating
/// arithmetic.
BlockFrequency &operator/=(BranchProbability Prob);
BlockFrequency operator/(BranchProbability Prob) const;
/// Adds another block frequency using saturating arithmetic.
BlockFrequency &operator+=(BlockFrequency Freq);
BlockFrequency operator+(BlockFrequency Freq) const;
/// Subtracts another block frequency using saturating arithmetic.
BlockFrequency &operator-=(BlockFrequency Freq);
BlockFrequency operator-(BlockFrequency Freq) const;
/// Shift block frequency to the right by count digits saturating to 1.
BlockFrequency &operator>>=(const unsigned count);
bool operator<(BlockFrequency RHS) const {
return Frequency < RHS.Frequency;
}
bool operator<=(BlockFrequency RHS) const {
return Frequency <= RHS.Frequency;
}
bool operator>(BlockFrequency RHS) const {
return Frequency > RHS.Frequency;
}
bool operator>=(BlockFrequency RHS) const {
return Frequency >= RHS.Frequency;
}
bool operator==(BlockFrequency RHS) const {
return Frequency == RHS.Frequency;
}
};
}
#endif