lib/Target/Mips/MipsPreLegalizerCombiner.cpp

   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
  21 #define DEBUG_TYPE "mips-prelegalizer-combiner"
  22
  23 using namespace llvm;
  24
  25 namespace {
  26 class MipsPreLegalizerCombinerInfo : public CombinerInfo {
  27 public:
  28   MipsPreLegalizerCombinerInfo()
  29       : CombinerInfo(/*AllowIllegalOps*/ true, /*ShouldLegalizeIllegal*/ false,
  30                      /*LegalizerInfo*/ nullptr, /*EnableOpt*/ false,
  31                      /*EnableOptSize*/ false, /*EnableMinSize*/ false) {}
  32   virtual bool combine(GISelChangeObserver &Observer, MachineInstr &MI,
  33                        MachineIRBuilder &B) const override;
  34 };
  35
  36 bool MipsPreLegalizerCombinerInfo::combine(GISelChangeObserver &Observer,
  37                                            MachineInstr &MI,
  38                                            MachineIRBuilder &B) const {
  39   CombinerHelper Helper(Observer, B);
  40
  41   switch (MI.getOpcode()) {
  42   default:
  43     return false;
  44   case TargetOpcode::G_LOAD:
  45   case TargetOpcode::G_SEXTLOAD:
  46   case TargetOpcode::G_ZEXTLOAD:
  47     return Helper.tryCombineExtendingLoads(MI);
  48   }
  49   return false;
  50 }
  51
  52 // Pass boilerplate
  53 // ================
  54
  55 class MipsPreLegalizerCombiner : public MachineFunctionPass {
  56 public:
  57   static char ID;
  58
  59   MipsPreLegalizerCombiner();
  60
  61   StringRef getPassName() const override { return "MipsPreLegalizerCombiner"; }
  62
  63   bool runOnMachineFunction(MachineFunction &MF) override;
  64
  65   void getAnalysisUsage(AnalysisUsage &AU) const override;
  66 };
  67 } // end anonymous namespace
  68
  69 void MipsPreLegalizerCombiner::getAnalysisUsage(AnalysisUsage &AU) const {
  70   AU.addRequired<TargetPassConfig>();
  71   AU.setPreservesCFG();
  72   getSelectionDAGFallbackAnalysisUsage(AU);
  73   MachineFunctionPass::getAnalysisUsage(AU);
  74 }
  75
  76 MipsPreLegalizerCombiner::MipsPreLegalizerCombiner() : MachineFunctionPass(ID) {
  77   initializeMipsPreLegalizerCombinerPass(*PassRegistry::getPassRegistry());
  78 }
  79
  80 bool MipsPreLegalizerCombiner::runOnMachineFunction(MachineFunction &MF) {
  81   if (MF.getProperties().hasProperty(
  82           MachineFunctionProperties::Property::FailedISel))
  83     return false;
  84   auto *TPC = &getAnalysis<TargetPassConfig>();
  85   MipsPreLegalizerCombinerInfo PCInfo;
  86   Combiner C(PCInfo, TPC);
  87   return C.combineMachineInstrs(MF, nullptr);
  88 }
  89
  90 char MipsPreLegalizerCombiner::ID = 0;
  91 INITIALIZE_PASS_BEGIN(MipsPreLegalizerCombiner, DEBUG_TYPE,
  92                       "Combine Mips machine instrs before legalization", false,
  93                       false)
  94 INITIALIZE_PASS_DEPENDENCY(TargetPassConfig)
  95 INITIALIZE_PASS_END(MipsPreLegalizerCombiner, DEBUG_TYPE,
  96                     "Combine Mips machine instrs before legalization", false,
  97                     false)
  98
  99 namespace llvm {
 100 FunctionPass *createMipsPreLegalizeCombiner() {
 101   return new MipsPreLegalizerCombiner();
 102 }
 103 } // end namespace llvm