1 ///===- LazyMachineBlockFrequencyInfo.cpp - Lazy Machine Block Frequency --===//
3 /// The LLVM Compiler Infrastructure
5 /// This file is distributed under the University of Illinois Open Source
6 /// License. See LICENSE.TXT for details.
8 ///===---------------------------------------------------------------------===//
10 /// This is an alternative analysis pass to MachineBlockFrequencyInfo. The
11 /// difference is that with this pass the block frequencies are not computed
12 /// when the analysis pass is executed but rather when the BFI result is
13 /// explicitly requested by the analysis client.
15 ///===---------------------------------------------------------------------===//
17 #include "llvm/CodeGen/LazyMachineBlockFrequencyInfo.h"
21 #define DEBUG_TYPE "lazy-machine-block-freq"
23 INITIALIZE_PASS_BEGIN(LazyMachineBlockFrequencyInfoPass, DEBUG_TYPE,
24 "Lazy Machine Block Frequency Analysis", true, true)
25 INITIALIZE_PASS_DEPENDENCY(MachineBranchProbabilityInfo)
26 INITIALIZE_PASS_DEPENDENCY(MachineLoopInfo)
27 INITIALIZE_PASS_END(LazyMachineBlockFrequencyInfoPass, DEBUG_TYPE,
28 "Lazy Machine Block Frequency Analysis", true, true)
30 char LazyMachineBlockFrequencyInfoPass::ID = 0;
32 LazyMachineBlockFrequencyInfoPass::LazyMachineBlockFrequencyInfoPass()
33 : MachineFunctionPass(ID) {
34 initializeLazyMachineBlockFrequencyInfoPassPass(
35 *PassRegistry::getPassRegistry());
38 void LazyMachineBlockFrequencyInfoPass::print(raw_ostream &OS,
39 const Module *M) const {
40 getBFI().print(OS, M);
43 void LazyMachineBlockFrequencyInfoPass::getAnalysisUsage(
44 AnalysisUsage &AU) const {
45 AU.addRequired<MachineBranchProbabilityInfo>();
47 MachineFunctionPass::getAnalysisUsage(AU);
50 void LazyMachineBlockFrequencyInfoPass::releaseMemory() {
56 MachineBlockFrequencyInfo &
57 LazyMachineBlockFrequencyInfoPass::calculateIfNotAvailable() const {
58 auto *MBFI = getAnalysisIfAvailable<MachineBlockFrequencyInfo>();
60 DEBUG(dbgs() << "MachineBlockFrequencyInfo is available\n");
64 auto &MBPI = getAnalysis<MachineBranchProbabilityInfo>();
65 auto *MLI = getAnalysisIfAvailable<MachineLoopInfo>();
66 auto *MDT = getAnalysisIfAvailable<MachineDominatorTree>();
67 DEBUG(dbgs() << "Building MachineBlockFrequencyInfo on the fly\n");
68 DEBUG(if (MLI) dbgs() << "LoopInfo is available\n");
71 DEBUG(dbgs() << "Building LoopInfo on the fly\n");
72 // First create a dominator tree.
73 DEBUG(if (MDT) dbgs() << "DominatorTree is available\n");
76 DEBUG(dbgs() << "Building DominatorTree on the fly\n");
77 OwnedMDT = make_unique<MachineDominatorTree>();
78 OwnedMDT->getBase().recalculate(*MF);
82 // Generate LoopInfo from it.
83 OwnedMLI = make_unique<MachineLoopInfo>();
84 OwnedMLI->getBase().analyze(MDT->getBase());
88 OwnedMBFI = make_unique<MachineBlockFrequencyInfo>();
89 OwnedMBFI->calculate(*MF, MBPI, *MLI);
90 return *OwnedMBFI.get();
93 bool LazyMachineBlockFrequencyInfoPass::runOnMachineFunction(