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