CycleAnalysis.cpp

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//===- CycleAnalysis.cpp - Compute CycleInfo for LLVM IR ------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
 
#include "llvm/Analysis/CycleAnalysis.h"
#include "llvm/IR/CFG.h" // for successors found by ADL in GenericCycleImpl.h
#include "llvm/InitializePasses.h"
#include "llvm/Support/CommandLine.h"
 
using namespace llvm;
 
// Always verify cycle info if expensive checking is enabled.
#ifdef EXPENSIVE_CHECKS
bool llvm::VerifyCycleInfo = true;
#else
bool llvm::VerifyCycleInfo = false;
#endif
static cl::opt<bool, true>
    VerifyCycleInfoX("verify-cycle-info", cl::location(VerifyCycleInfo),
                     cl::Hidden,
                     cl::desc("Verify cycle info (time consuming)"));
 
namespace llvm {
class Module;
} // namespace llvm
 
CycleInfo CycleAnalysis::run(Function &F, FunctionAnalysisManager &) {
  CycleInfo CI;
  CI.compute(F);
  return CI;
}
 
bool CycleInfo::invalidate(Function &F, const PreservedAnalyses &PA,
                           FunctionAnalysisManager::Invalidator &) {
  // Check whether the analysis, all analyses on functions, or the function's
  // CFG have been preserved.
  auto PAC = PA.getChecker<CycleAnalysis>();
  return !(PAC.preserved() || PAC.preservedSet<AllAnalysesOn<Function>>() ||
           PAC.preservedSet<CFGAnalyses>());
}
 
AnalysisKey CycleAnalysis::Key;
 
CycleInfoPrinterPass::CycleInfoPrinterPass(raw_ostream &OS) : OS(OS) {}
 
PreservedAnalyses CycleInfoPrinterPass::run(Function &F,
                                            FunctionAnalysisManager &AM) {
  OS << "CycleInfo for function: " << F.getName() << "\n";
  AM.getResult<CycleAnalysis>(F).print(OS);
 
  return PreservedAnalyses::all();
}
 
PreservedAnalyses CycleInfoVerifierPass::run(Function &F,
                                             FunctionAnalysisManager &AM) {
  CycleInfo &CI = AM.getResult<CycleAnalysis>(F);
  CI.verify();
  return PreservedAnalyses::all();
}
 
//===----------------------------------------------------------------------===//
//  CycleInfoWrapperPass Implementation
//===----------------------------------------------------------------------===//
//
// The implementation details of the wrapper pass that holds a CycleInfo
// suitable for use with the legacy pass manager.
//
//===----------------------------------------------------------------------===//
 
char CycleInfoWrapperPass::ID = 0;
 
CycleInfoWrapperPass::CycleInfoWrapperPass() : FunctionPass(ID) {}
 
INITIALIZE_PASS_BEGIN(CycleInfoWrapperPass, "cycles", "Cycle Info Analysis",
                      true, true)
INITIALIZE_PASS_END(CycleInfoWrapperPass, "cycles", "Cycle Info Analysis", true,
                    true)
 
void CycleInfoWrapperPass::getAnalysisUsage(AnalysisUsage &AU) const {
  AU.setPreservesAll();
}
 
bool CycleInfoWrapperPass::runOnFunction(Function &Func) {
  CI.clear();
 
  F = &Func;
  CI.compute(Func);
  return false;
}
 
void CycleInfoWrapperPass::print(raw_ostream &OS, const Module *) const {
  OS << "CycleInfo for function: " << F->getName() << "\n";
  CI.print(OS);
}
 
void CycleInfoWrapperPass::verifyAnalysis() const {
  if (VerifyCycleInfo)
    CI.verify();
}
 
void CycleInfoWrapperPass::releaseMemory() {
  CI.clear();
  F = nullptr;
}