/*========================== begin_copyright_notice ============================

Copyright (C) 2025 Intel Corporation

SPDX-License-Identifier: MIT

============================= end_copyright_notice ===========================*/

#include "common/LLVMWarningsPush.hpp"
#include "llvmWrapper/Transforms/Scalar/LoopDeletion.h"

#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/AssumptionCache.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Analysis/MemorySSA.h"
#include "llvm/Analysis/ScalarEvolution.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/PassManager.h"
#include "llvm/Pass.h"
#include "llvm/Passes/PassBuilder.h"
#include "llvm/Transforms/Scalar.h"
#include "llvm/Transforms/Scalar/LoopDeletion.h"
#include "llvm/Transforms/Scalar/LoopPassManager.h"

#include "llvmWrapper/Transforms/InitializePasses.h"
#include "common/LLVMWarningsPop.hpp"

#include "Compiler/IGCPassSupport.h"

using namespace llvm;

namespace IGCLLVM {

LoopDeletionLegacyPassWrapper::LoopDeletionLegacyPassWrapper() : FunctionPass(ID) {
  initializeLoopDeletionLegacyPassWrapperPass(*PassRegistry::getPassRegistry());
  PB.registerModuleAnalyses(MAM);
  PB.registerCGSCCAnalyses(CGAM);
  PB.registerFunctionAnalyses(FAM);
  PB.registerLoopAnalyses(LAM);
  PB.crossRegisterProxies(LAM, FAM, CGAM, MAM);
}

bool LoopDeletionLegacyPassWrapper::runOnFunction(Function &F) {
  // The legacy pass manager implementation of the pass used to skip some functions. In the new pass manager
  // implementation this is done globally through the pass manager. Check and skip explicitly here to preserve the old
  // behavior.
  if (skipFunction(F))
    return false;

  // Run the New Pass Manager implementation via the loop-pass adaptor.
  // Enable MemorySSA so the pass can update it when it performs transformations.
  auto Adaptor = createFunctionToLoopPassAdaptor(LoopDeletionPass(), /*UseMemorySSA=*/true);

  PreservedAnalyses PA = Adaptor.run(F, FAM);
  return !PA.areAllPreserved();
}

void LoopDeletionLegacyPassWrapper::getAnalysisUsage(AnalysisUsage &AU) const {
  AU.addRequired<AAResultsWrapperPass>();
  AU.addRequired<AssumptionCacheTracker>();
  AU.addRequired<DominatorTreeWrapperPass>();
  AU.addRequired<LoopInfoWrapperPass>();
  AU.addRequired<ScalarEvolutionWrapperPass>();
  AU.addRequired<MemorySSAWrapperPass>();
}

char LoopDeletionLegacyPassWrapper::ID = 0;

Pass *createLegacyWrappedLoopDeletionPass() { return new LoopDeletionLegacyPassWrapper(); }

} // namespace IGCLLVM

using namespace IGCLLVM;

#define PASS_FLAG "loop-deletion-legacy-wrapped"
#define PASS_DESCRIPTION "Loop Deletion LPM Wrapped"
#define PASS_CFG_ONLY false
#define PASS_ANALYSIS false

IGC_INITIALIZE_PASS_BEGIN(LoopDeletionLegacyPassWrapper, PASS_FLAG, PASS_DESCRIPTION, PASS_CFG_ONLY, PASS_ANALYSIS)
IGC_INITIALIZE_PASS_DEPENDENCY(AAResultsWrapperPass)
IGC_INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)
IGC_INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
IGC_INITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass)
IGC_INITIALIZE_PASS_DEPENDENCY(ScalarEvolutionWrapperPass)
IGC_INITIALIZE_PASS_DEPENDENCY(MemorySSAWrapperPass)
IGC_INITIALIZE_PASS_END(LoopDeletionLegacyPassWrapper, PASS_FLAG, PASS_DESCRIPTION, PASS_CFG_ONLY, PASS_ANALYSIS)
