llvm/lib/Support/BlockFrequency.cpp
Duncan P. N. Exon Smith 07f96126af blockfreq: Defer to BranchProbability::scale() (again)
Change `BlockFrequency` to defer to `BranchProbability::scale()` and
`BranchProbability::scaleByInverse()`.

This removes `BlockFrequency::scale()` from its API (and drops the
ability to see the remainder), but the only user was the unit tests.  If
some code in the future needs an API that exposes the remainder, we can
add something to `BranchProbability`, but I find that unlikely.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207550 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-29 16:31:29 +00:00

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;
}