llvm/llvm/include/llvm/CodeGen/MachineLoopInfo.h

//===- llvm/CodeGen/MachineLoopInfo.h - Natural Loop Calculator -*- 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 file defines the MachineLoopInfo class that is used to identify natural
// loops and determine the loop depth of various nodes of the CFG.  Note that
// natural loops may actually be several loops that share the same header node.
//
// This analysis calculates the nesting structure of loops in a function.  For
// each natural loop identified, this analysis identifies natural loops
// contained entirely within the loop and the basic blocks the make up the loop.
//
// It can calculate on the fly various bits of information, for example:
//
//  * whether there is a preheader for the loop
//  * the number of back edges to the header
//  * whether or not a particular block branches out of the loop
//  * the successor blocks of the loop
//  * the loop depth
//  * the trip count
//  * etc...
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_CODEGEN_MACHINELOOPINFO_H
#define LLVM_CODEGEN_MACHINELOOPINFO_H

#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachinePassManager.h"
#include "llvm/IR/CFG.h"
#include "llvm/IR/DebugLoc.h"
#include "llvm/Support/GenericLoopInfo.h"

namespace llvm {

class MachineDominatorTree;
// Implementation in LoopInfoImpl.h
class MachineLoop;
extern template class LoopBase<MachineBasicBlock, MachineLoop>;

class MachineLoop : public LoopBase<MachineBasicBlock, MachineLoop> { … };

// Implementation in LoopInfoImpl.h
extern template class LoopInfoBase<MachineBasicBlock, MachineLoop>;

class MachineLoopInfo : public LoopInfoBase<MachineBasicBlock, MachineLoop> { … };

/// Analysis pass that exposes the \c MachineLoopInfo for a machine function.
class MachineLoopAnalysis : public AnalysisInfoMixin<MachineLoopAnalysis> { … };

/// Printer pass for the \c LoopAnalysis results.
class MachineLoopPrinterPass : public PassInfoMixin<MachineLoopPrinterPass> { … };

class MachineLoopInfoWrapperPass : public MachineFunctionPass { … };

// Allow clients to walk the list of nested loops...
template <> struct GraphTraits<const MachineLoop*> { … };

template <> struct GraphTraits<MachineLoop*> { … };

} // end namespace llvm

#endif // LLVM_CODEGEN_MACHINELOOPINFO_H