llvm/llvm/include/llvm/Transforms/Scalar/Reassociate.h

//===- Reassociate.h - Reassociate binary expressions -----------*- 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
//
//===----------------------------------------------------------------------===//
//
// This pass reassociates commutative expressions in an order that is designed
// to promote better constant propagation, GCSE, LICM, PRE, etc.
//
// For example: 4 + (x + 5) -> x + (4 + 5)
//
// In the implementation of this algorithm, constants are assigned rank = 0,
// function arguments are rank = 1, and other values are assigned ranks
// corresponding to the reverse post order traversal of current function
// (starting at 2), which effectively gives values in deep loops higher rank
// than values not in loops.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_TRANSFORMS_SCALAR_REASSOCIATE_H
#define LLVM_TRANSFORMS_SCALAR_REASSOCIATE_H

#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/PostOrderIterator.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/PassManager.h"
#include "llvm/IR/ValueHandle.h"
#include <deque>

namespace llvm {

class APInt;
class BasicBlock;
class BinaryOperator;
class Function;
class Instruction;
class IRBuilderBase;
class Value;

/// A private "module" namespace for types and utilities used by Reassociate.
/// These are implementation details and should not be used by clients.
namespace reassociate {

struct ValueEntry { … };

inline bool operator<(const ValueEntry &LHS, const ValueEntry &RHS) { … }

/// Utility class representing a base and exponent pair which form one
/// factor of some product.
struct Factor { … };

struct OverflowTracking { … };

class XorOpnd;

} // end namespace reassociate

/// Reassociate commutative expressions.
class ReassociatePass : public PassInfoMixin<ReassociatePass> { … };

} // end namespace llvm

#endif // LLVM_TRANSFORMS_SCALAR_REASSOCIATE_H