MipsPreLegalizerCombiner.cpp revision 360784 
1//=== lib/CodeGen/GlobalISel/MipsPreLegalizerCombiner.cpp --------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This pass does combining of machine instructions at the generic MI level,
10// before the legalizer.
11//
12//===----------------------------------------------------------------------===//
13
14#include "MipsTargetMachine.h"
15#include "llvm/CodeGen/GlobalISel/Combiner.h"
16#include "llvm/CodeGen/GlobalISel/CombinerHelper.h"
17#include "llvm/CodeGen/GlobalISel/CombinerInfo.h"
18#include "llvm/CodeGen/GlobalISel/MIPatternMatch.h"
19#include "llvm/CodeGen/TargetPassConfig.h"
20#include "llvm/InitializePasses.h"
21
22#define DEBUG_TYPE "mips-prelegalizer-combiner"
23
24using namespace llvm;
25
26namespace {
27class MipsPreLegalizerCombinerInfo : public CombinerInfo {
28public:
29  MipsPreLegalizerCombinerInfo()
30      : CombinerInfo(/*AllowIllegalOps*/ true, /*ShouldLegalizeIllegal*/ false,
31                     /*LegalizerInfo*/ nullptr, /*EnableOpt*/ false,
32                     /*EnableOptSize*/ false, /*EnableMinSize*/ false) {}
33  virtual bool combine(GISelChangeObserver &Observer, MachineInstr &MI,
34                       MachineIRBuilder &B) const override;
35};
36
37bool MipsPreLegalizerCombinerInfo::combine(GISelChangeObserver &Observer,
38                                           MachineInstr &MI,
39                                           MachineIRBuilder &B) const {
40  CombinerHelper Helper(Observer, B);
41
42  switch (MI.getOpcode()) {
43  default:
44    return false;
45  case TargetOpcode::G_LOAD:
46  case TargetOpcode::G_SEXTLOAD:
47  case TargetOpcode::G_ZEXTLOAD:
48    return Helper.tryCombineExtendingLoads(MI);
49  }
50  return false;
51}
52
53// Pass boilerplate
54// ================
55
56class MipsPreLegalizerCombiner : public MachineFunctionPass {
57public:
58  static char ID;
59
60  MipsPreLegalizerCombiner();
61
62  StringRef getPassName() const override { return "MipsPreLegalizerCombiner"; }
63
64  bool runOnMachineFunction(MachineFunction &MF) override;
65
66  void getAnalysisUsage(AnalysisUsage &AU) const override;
67};
68} // end anonymous namespace
69
70void MipsPreLegalizerCombiner::getAnalysisUsage(AnalysisUsage &AU) const {
71  AU.addRequired<TargetPassConfig>();
72  AU.setPreservesCFG();
73  getSelectionDAGFallbackAnalysisUsage(AU);
74  MachineFunctionPass::getAnalysisUsage(AU);
75}
76
77MipsPreLegalizerCombiner::MipsPreLegalizerCombiner() : MachineFunctionPass(ID) {
78  initializeMipsPreLegalizerCombinerPass(*PassRegistry::getPassRegistry());
79}
80
81bool MipsPreLegalizerCombiner::runOnMachineFunction(MachineFunction &MF) {
82  if (MF.getProperties().hasProperty(
83          MachineFunctionProperties::Property::FailedISel))
84    return false;
85  auto *TPC = &getAnalysis<TargetPassConfig>();
86  MipsPreLegalizerCombinerInfo PCInfo;
87  Combiner C(PCInfo, TPC);
88  return C.combineMachineInstrs(MF, nullptr);
89}
90
91char MipsPreLegalizerCombiner::ID = 0;
92INITIALIZE_PASS_BEGIN(MipsPreLegalizerCombiner, DEBUG_TYPE,
93                      "Combine Mips machine instrs before legalization", false,
94                      false)
95INITIALIZE_PASS_DEPENDENCY(TargetPassConfig)
96INITIALIZE_PASS_END(MipsPreLegalizerCombiner, DEBUG_TYPE,
97                    "Combine Mips machine instrs before legalization", false,
98                    false)
99
100namespace llvm {
101FunctionPass *createMipsPreLegalizeCombiner() {
102  return new MipsPreLegalizerCombiner();
103}
104} // end namespace llvm
105