llvm/llvm/include/llvm/CodeGen/ReachingDefAnalysis.h

//==--- llvm/CodeGen/ReachingDefAnalysis.h - Reaching Def Analysis -*- 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 Reaching Defs Analysis pass.
///
/// This pass tracks for each instruction what is the "closest" reaching def of
/// a given register. It is used by BreakFalseDeps (for clearance calculation)
/// and ExecutionDomainFix (for arbitrating conflicting domains).
///
/// Note that this is different from the usual definition notion of liveness.
/// The CPU doesn't care whether or not we consider a register killed.
///
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_CODEGEN_REACHINGDEFANALYSIS_H
#define LLVM_CODEGEN_REACHINGDEFANALYSIS_H

#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/TinyPtrVector.h"
#include "llvm/CodeGen/LoopTraversal.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/InitializePasses.h"

namespace llvm {

class MachineBasicBlock;
class MachineInstr;

/// Thin wrapper around "int" used to store reaching definitions,
/// using an encoding that makes it compatible with TinyPtrVector.
/// The 0th LSB is forced zero (and will be used for pointer union tagging),
/// The 1st LSB is forced one (to make sure the value is non-zero).
class ReachingDef { … };

template<>
struct PointerLikeTypeTraits<ReachingDef> { … };

// The storage for all reaching definitions.
class MBBReachingDefsInfo { … };

/// This class provides the reaching def analysis.
class ReachingDefAnalysis : public MachineFunctionPass { … };

} // namespace llvm

#endif // LLVM_CODEGEN_REACHINGDEFANALYSIS_H