llvm/llvm/lib/Transforms/Scalar/LoopTermFold.cpp

//===- LoopTermFold.cpp - Eliminate last use of IV in exit branch----------===//
//
// 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/Transforms/Scalar/LoopTermFold.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/LoopAnalysisManager.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Analysis/LoopPass.h"
#include "llvm/Analysis/MemorySSA.h"
#include "llvm/Analysis/MemorySSAUpdater.h"
#include "llvm/Analysis/ScalarEvolution.h"
#include "llvm/Analysis/ScalarEvolutionExpressions.h"
#include "llvm/Analysis/TargetLibraryInfo.h"
#include "llvm/Analysis/TargetTransformInfo.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/Config/llvm-config.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/InstrTypes.h"
#include "llvm/IR/Instruction.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/Type.h"
#include "llvm/IR/Value.h"
#include "llvm/InitializePasses.h"
#include "llvm/Pass.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Transforms/Scalar.h"
#include "llvm/Transforms/Utils.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
#include "llvm/Transforms/Utils/Local.h"
#include "llvm/Transforms/Utils/LoopUtils.h"
#include "llvm/Transforms/Utils/ScalarEvolutionExpander.h"
#include <cassert>
#include <optional>
#include <utility>

usingnamespacellvm;

#define DEBUG_TYPE …

STATISTIC(NumTermFold,
          "Number of terminating condition fold recognized and performed");

static std::optional<std::tuple<PHINode *, PHINode *, const SCEV *, bool>>
canFoldTermCondOfLoop(Loop *L, ScalarEvolution &SE, DominatorTree &DT,
                      const LoopInfo &LI, const TargetTransformInfo &TTI) { … }

static bool RunTermFold(Loop *L, ScalarEvolution &SE, DominatorTree &DT,
                        LoopInfo &LI, const TargetTransformInfo &TTI,
                        TargetLibraryInfo &TLI, MemorySSA *MSSA) { … }

namespace {

class LoopTermFold : public LoopPass { … };

} // end anonymous namespace

LoopTermFold::LoopTermFold() : … { … }

void LoopTermFold::getAnalysisUsage(AnalysisUsage &AU) const { … }

bool LoopTermFold::runOnLoop(Loop *L, LPPassManager & /*LPM*/) { … }

PreservedAnalyses LoopTermFoldPass::run(Loop &L, LoopAnalysisManager &AM,
                                        LoopStandardAnalysisResults &AR,
                                        LPMUpdater &) { … }

char LoopTermFold::ID = …;

INITIALIZE_PASS_BEGIN(LoopTermFold, "loop-term-fold", "Loop Terminator Folding",
                      false, false)
INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass)
INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
INITIALIZE_PASS_DEPENDENCY(ScalarEvolutionWrapperPass)
INITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass)
INITIALIZE_PASS_DEPENDENCY(LoopSimplify)
INITIALIZE_PASS_END(LoopTermFold, "loop-term-fold", "Loop Terminator Folding",
                    false, false)

Pass *llvm::createLoopTermFoldPass() { … }