llvm-mirror/lib/Analysis/LazyBlockFrequencyInfo.cpp
Adam Nemet 9449a00cc1 [BPI] Add new LazyBPI analysis
Summary:
The motivation is the same as in D22141: In order to add the hotness
attribute to optimization remarks we need BFI to be available in all
passes that emit optimization remarks.  BFI depends on BPI so unless we
make this lazy as well we would still compute BPI unconditionally.

The solution is to use the new LazyBPI pass in LazyBFI and only compute
BPI when computation of BFI is requested by the client.

I extended the laziness test using a LoopDistribute test to also cover
BPI.

Reviewers: hfinkel, davidxl

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D22835

llvm-svn: 277083
2016-07-28 23:31:12 +00:00

68 lines
2.5 KiB
C++

//===- LazyBlockFrequencyInfo.cpp - Lazy Block Frequency 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 BlockFrequencyInfoWrapperPass. The
// difference is that with this pass the block frequencies are not computed when
// the analysis pass is executed but rather when the BFI results is explicitly
// requested by the analysis client.
//
//===----------------------------------------------------------------------===//
#include "llvm/Analysis/LazyBlockFrequencyInfo.h"
#include "llvm/Analysis/LazyBranchProbabilityInfo.h"
#include "llvm/Analysis/LoopInfo.h"
using namespace llvm;
#define DEBUG_TYPE "lazy-block-freq"
INITIALIZE_PASS_BEGIN(LazyBlockFrequencyInfoPass, DEBUG_TYPE,
"Lazy Block Frequency Analysis", true, true)
INITIALIZE_PASS_DEPENDENCY(LazyBPIPass)
INITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass)
INITIALIZE_PASS_END(LazyBlockFrequencyInfoPass, DEBUG_TYPE,
"Lazy Block Frequency Analysis", true, true)
char LazyBlockFrequencyInfoPass::ID = 0;
LazyBlockFrequencyInfoPass::LazyBlockFrequencyInfoPass() : FunctionPass(ID) {
initializeLazyBlockFrequencyInfoPassPass(*PassRegistry::getPassRegistry());
}
void LazyBlockFrequencyInfoPass::print(raw_ostream &OS, const Module *) const {
LBFI.getCalculated().print(OS);
}
void LazyBlockFrequencyInfoPass::getAnalysisUsage(AnalysisUsage &AU) const {
LazyBranchProbabilityInfoPass::getLazyBPIAnalysisUsage(AU);
AU.addRequired<LoopInfoWrapperPass>();
AU.setPreservesAll();
}
void LazyBlockFrequencyInfoPass::releaseMemory() { LBFI.releaseMemory(); }
bool LazyBlockFrequencyInfoPass::runOnFunction(Function &F) {
auto &BPIPass = getAnalysis<LazyBranchProbabilityInfoPass>();
LoopInfo &LI = getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
LBFI.setAnalysis(&F, &BPIPass, &LI);
return false;
}
void LazyBlockFrequencyInfoPass::getLazyBFIAnalysisUsage(AnalysisUsage &AU) {
LazyBranchProbabilityInfoPass::getLazyBPIAnalysisUsage(AU);
AU.addRequired<LazyBlockFrequencyInfoPass>();
AU.addRequired<LoopInfoWrapperPass>();
}
void llvm::initializeLazyBFIPassPass(PassRegistry &Registry) {
initializeLazyBPIPassPass(Registry);
INITIALIZE_PASS_DEPENDENCY(LazyBlockFrequencyInfoPass);
INITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass);
}