llvm-project/llvm/lib/Support/BlockFrequency.cpp

83 lines
2.1 KiB
C++

//====--------------- lib/Support/BlockFrequency.cpp -----------*- 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.
//
//===----------------------------------------------------------------------===//
#include "llvm/Support/BlockFrequency.h"
#include <cassert>
using namespace llvm;
BlockFrequency &BlockFrequency::operator*=(BranchProbability Prob) {
Frequency = Prob.scale(Frequency);
return *this;
}
BlockFrequency BlockFrequency::operator*(BranchProbability Prob) const {
BlockFrequency Freq(Frequency);
Freq *= Prob;
return Freq;
}
BlockFrequency &BlockFrequency::operator/=(BranchProbability Prob) {
Frequency = Prob.scaleByInverse(Frequency);
return *this;
}
BlockFrequency BlockFrequency::operator/(BranchProbability Prob) const {
BlockFrequency Freq(Frequency);
Freq /= Prob;
return Freq;
}
BlockFrequency &BlockFrequency::operator+=(BlockFrequency Freq) {
uint64_t Before = Freq.Frequency;
Frequency += Freq.Frequency;
// If overflow, set frequency to the maximum value.
if (Frequency < Before)
Frequency = UINT64_MAX;
return *this;
}
BlockFrequency BlockFrequency::operator+(BlockFrequency Freq) const {
BlockFrequency NewFreq(Frequency);
NewFreq += Freq;
return NewFreq;
}
BlockFrequency &BlockFrequency::operator-=(BlockFrequency Freq) {
// If underflow, set frequency to 0.
if (Frequency <= Freq.Frequency)
Frequency = 0;
else
Frequency -= Freq.Frequency;
return *this;
}
BlockFrequency BlockFrequency::operator-(BlockFrequency Freq) const {
BlockFrequency NewFreq(Frequency);
NewFreq -= Freq;
return NewFreq;
}
BlockFrequency &BlockFrequency::operator>>=(const unsigned count) {
// Frequency can never be 0 by design.
assert(Frequency != 0);
// Shift right by count.
Frequency >>= count;
// Saturate to 1 if we are 0.
Frequency |= Frequency == 0;
return *this;
}