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

73 lines
1.9 KiB
C++

//====--------------- lib/Support/BlockFrequency.cpp -----------*- 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.
//
//===----------------------------------------------------------------------===//
#include "llvm/Support/BranchProbability.h"
#include "llvm/Support/BlockFrequency.h"
#include "llvm/Support/raw_ostream.h"
#include <cassert>
using namespace llvm;
BlockFrequency &BlockFrequency::operator*=(const BranchProbability &Prob) {
Frequency = Prob.scale(Frequency);
return *this;
}
const BlockFrequency
BlockFrequency::operator*(const BranchProbability &Prob) const {
BlockFrequency Freq(Frequency);
Freq *= Prob;
return Freq;
}
BlockFrequency &BlockFrequency::operator/=(const BranchProbability &Prob) {
Frequency = Prob.scaleByInverse(Frequency);
return *this;
}
BlockFrequency BlockFrequency::operator/(const BranchProbability &Prob) const {
BlockFrequency Freq(Frequency);
Freq /= Prob;
return Freq;
}
BlockFrequency &BlockFrequency::operator+=(const 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;
}
const BlockFrequency
BlockFrequency::operator+(const BlockFrequency &Prob) const {
BlockFrequency Freq(Frequency);
Freq += Prob;
return Freq;
}
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;
}