llvm-project/llvm/lib/Analysis/LazyBranchProbabilityInfo.cpp

70 lines
2.6 KiB
C++

//===- LazyBranchProbabilityInfo.cpp - Lazy Branch Probability Analysis ---===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This is an alternative analysis pass to BranchProbabilityInfoWrapperPass.
// The difference is that with this pass the branch probabilities are not
// computed when the analysis pass is executed but rather when the BPI results
// is explicitly requested by the analysis client.
//
//===----------------------------------------------------------------------===//
#include "llvm/Analysis/LazyBranchProbabilityInfo.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Analysis/TargetLibraryInfo.h"
using namespace llvm;
#define DEBUG_TYPE "lazy-branch-prob"
INITIALIZE_PASS_BEGIN(LazyBranchProbabilityInfoPass, DEBUG_TYPE,
"Lazy Branch Probability Analysis", true, true)
INITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass)
INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)
INITIALIZE_PASS_END(LazyBranchProbabilityInfoPass, DEBUG_TYPE,
"Lazy Branch Probability Analysis", true, true)
char LazyBranchProbabilityInfoPass::ID = 0;
LazyBranchProbabilityInfoPass::LazyBranchProbabilityInfoPass()
: FunctionPass(ID) {
initializeLazyBranchProbabilityInfoPassPass(*PassRegistry::getPassRegistry());
}
void LazyBranchProbabilityInfoPass::print(raw_ostream &OS,
const Module *) const {
LBPI->getCalculated().print(OS);
}
void LazyBranchProbabilityInfoPass::getAnalysisUsage(AnalysisUsage &AU) const {
AU.addRequired<LoopInfoWrapperPass>();
AU.addRequired<TargetLibraryInfoWrapperPass>();
AU.setPreservesAll();
}
void LazyBranchProbabilityInfoPass::releaseMemory() { LBPI.reset(); }
bool LazyBranchProbabilityInfoPass::runOnFunction(Function &F) {
LoopInfo &LI = getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
TargetLibraryInfo &TLI = getAnalysis<TargetLibraryInfoWrapperPass>().getTLI();
LBPI = llvm::make_unique<LazyBranchProbabilityInfo>(&F, &LI, &TLI);
return false;
}
void LazyBranchProbabilityInfoPass::getLazyBPIAnalysisUsage(AnalysisUsage &AU) {
AU.addRequired<LazyBranchProbabilityInfoPass>();
AU.addRequired<LoopInfoWrapperPass>();
AU.addRequired<TargetLibraryInfoWrapperPass>();
}
void llvm::initializeLazyBPIPassPass(PassRegistry &Registry) {
INITIALIZE_PASS_DEPENDENCY(LazyBranchProbabilityInfoPass);
INITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass);
INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass);
}