llvm/llvm/include/llvm/Transforms/Scalar/GVN.h

//===- GVN.h - Eliminate redundant values and loads -------------*- C++ -*-===//
//
// 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
//
//===----------------------------------------------------------------------===//
/// \file
/// This file provides the interface for LLVM's Global Value Numbering pass
/// which eliminates fully redundant instructions. It also does somewhat Ad-Hoc
/// PRE and dead load elimination.
///
//===----------------------------------------------------------------------===//

#ifndef LLVM_TRANSFORMS_SCALAR_GVN_H
#define LLVM_TRANSFORMS_SCALAR_GVN_H

#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/MapVector.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/InstrTypes.h"
#include "llvm/IR/PassManager.h"
#include "llvm/IR/ValueHandle.h"
#include "llvm/Support/Allocator.h"
#include "llvm/Support/Compiler.h"
#include <cstdint>
#include <optional>
#include <utility>
#include <vector>

namespace llvm {

class AAResults;
class AssumeInst;
class AssumptionCache;
class BasicBlock;
class BranchInst;
class CallInst;
class ExtractValueInst;
class Function;
class FunctionPass;
class GetElementPtrInst;
class ImplicitControlFlowTracking;
class LoadInst;
class LoopInfo;
class MemDepResult;
class MemoryDependenceResults;
class MemorySSA;
class MemorySSAUpdater;
class NonLocalDepResult;
class OptimizationRemarkEmitter;
class PHINode;
class TargetLibraryInfo;
class Value;
/// A private "module" namespace for types and utilities used by GVN. These
/// are implementation details and should not be used by clients.
namespace LLVM_LIBRARY_VISIBILITY gvn {

struct AvailableValue;
struct AvailableValueInBlock;
class GVNLegacyPass;

} // end namespace gvn

/// A set of parameters to control various transforms performed by GVN pass.
//  Each of the optional boolean parameters can be set to:
///      true - enabling the transformation.
///      false - disabling the transformation.
///      None - relying on a global default.
/// Intended use is to create a default object, modify parameters with
/// additional setters and then pass it to GVN.
struct GVNOptions { … };

/// The core GVN pass object.
///
/// FIXME: We should have a good summary of the GVN algorithm implemented by
/// this particular pass here.
class GVNPass : public PassInfoMixin<GVNPass> { … };

/// Create a legacy GVN pass. This also allows parameterizing whether or not
/// MemDep is enabled.
FunctionPass *createGVNPass(bool NoMemDepAnalysis = false);

/// A simple and fast domtree-based GVN pass to hoist common expressions
/// from sibling branches.
struct GVNHoistPass : PassInfoMixin<GVNHoistPass> { … };

/// Uses an "inverted" value numbering to decide the similarity of
/// expressions and sinks similar expressions into successors.
struct GVNSinkPass : PassInfoMixin<GVNSinkPass> { … };

} // end namespace llvm

#endif // LLVM_TRANSFORMS_SCALAR_GVN_H