llvm/llvm/lib/CodeGen/GlobalISel/Combiner.cpp

//===-- lib/CodeGen/GlobalISel/Combiner.cpp -------------------------------===//
//
// 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 constains common code to combine machine functions at generic
// level.
//===----------------------------------------------------------------------===//

#include "llvm/CodeGen/GlobalISel/Combiner.h"
#include "llvm/ADT/PostOrderIterator.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/CodeGen/GlobalISel/CSEInfo.h"
#include "llvm/CodeGen/GlobalISel/CSEMIRBuilder.h"
#include "llvm/CodeGen/GlobalISel/CombinerInfo.h"
#include "llvm/CodeGen/GlobalISel/GISelChangeObserver.h"
#include "llvm/CodeGen/GlobalISel/GISelWorkList.h"
#include "llvm/CodeGen/GlobalISel/MachineIRBuilder.h"
#include "llvm/CodeGen/GlobalISel/Utils.h"
#include "llvm/CodeGen/MachineOptimizationRemarkEmitter.h"
#include "llvm/Support/Debug.h"

#define DEBUG_TYPE …

usingnamespacellvm;

STATISTIC(NumOneIteration, "Number of functions with one iteration");
STATISTIC(NumTwoIterations, "Number of functions with two iterations");
STATISTIC(NumThreeOrMoreIterations,
          "Number of functions with three or more iterations");

namespace llvm {
cl::OptionCategory GICombinerOptionCategory(
    "GlobalISel Combiner",
    "Control the rules which are enabled. These options all take a comma "
    "separated list of rules to disable and may be specified by number "
    "or number range (e.g. 1-10)."
#ifndef NDEBUG
    " They may also be specified by name."
#endif
);
} // end namespace llvm

/// This class acts as the glue that joins the CombinerHelper to the overall
/// Combine algorithm. The CombinerHelper is intended to report the
/// modifications it makes to the MIR to the GISelChangeObserver and the
/// observer subclass will act on these events.
class Combiner::WorkListMaintainer : public GISelChangeObserver { … };

/// A configurable WorkListMaintainer implementation.
/// The ObserverLevel determines how the WorkListMaintainer reacts to MIR
/// changes.
template <CombinerInfo::ObserverLevel Lvl>
class Combiner::WorkListMaintainerImpl : public Combiner::WorkListMaintainer { … };

std::unique_ptr<Combiner::WorkListMaintainer>
Combiner::WorkListMaintainer::create(Level Lvl, WorkListTy &WorkList,
                                     MachineRegisterInfo &MRI) { … }

Combiner::Combiner(MachineFunction &MF, CombinerInfo &CInfo,
                   const TargetPassConfig *TPC, GISelKnownBits *KB,
                   GISelCSEInfo *CSEInfo)
    : … { … }

Combiner::~Combiner() = default;

bool Combiner::tryDCE(MachineInstr &MI, MachineRegisterInfo &MRI) { … }

bool Combiner::combineMachineInstrs() { … }