llvm/lib/Support/BlockFrequency.cpp

   1 //====--------------- lib/Support/BlockFrequency.cpp -----------*- C++ -*-====//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file implements Block Frequency class.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "llvm/Support/BlockFrequency.h"
  14 #include "llvm/Support/BranchProbability.h"
  15 #include "llvm/Support/MathExtras.h"
  16 #include "llvm/Support/ScaledNumber.h"
  17 #include "llvm/Support/raw_ostream.h"
  18
  19 using namespace llvm;
  20
  21 BlockFrequency &BlockFrequency::operator*=(BranchProbability Prob) {
  22   Frequency = Prob.scale(Frequency);
  23   return *this;
  24 }
  25
  26 BlockFrequency BlockFrequency::operator*(BranchProbability Prob) const {
  27   BlockFrequency Freq(Frequency);
  28   Freq *= Prob;
  29   return Freq;
  30 }
  31
  32 BlockFrequency &BlockFrequency::operator/=(BranchProbability Prob) {
  33   Frequency = Prob.scaleByInverse(Frequency);
  34   return *this;
  35 }
  36
  37 BlockFrequency BlockFrequency::operator/(BranchProbability Prob) const {
  38   BlockFrequency Freq(Frequency);
  39   Freq /= Prob;
  40   return Freq;
  41 }
  42
  43 std::optional<BlockFrequency> BlockFrequency::mul(uint64_t Factor) const {
  44   bool Overflow;
  45   uint64_t ResultFrequency = SaturatingMultiply(Frequency, Factor, &Overflow);
  46   if (Overflow)
  47     return {};
  48   return BlockFrequency(ResultFrequency);
  49 }
  50
  51 void llvm::printRelativeBlockFreq(raw_ostream &OS, BlockFrequency EntryFreq,
  52                                   BlockFrequency Freq) {
  53   if (Freq == BlockFrequency(0)) {
  54     OS << "0";
  55     return;
  56   }
  57   if (EntryFreq == BlockFrequency(0)) {
  58     OS << "<invalid BFI>";
  59     return;
  60   }
  61   ScaledNumber<uint64_t> Block(Freq.getFrequency(), 0);
  62   ScaledNumber<uint64_t> Entry(EntryFreq.getFrequency(), 0);
  63   OS << Block / Entry;
  64 }