contrib/llvm-project/llvm/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 #include "llvm/InitializePasses.h"
  21
  22 #define DEBUG_TYPE "mips-prelegalizer-combiner"
  23
  24 using namespace llvm;
  25
  26 namespace {
  27 class MipsPreLegalizerCombinerInfo : public CombinerInfo {
  28 public:
  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
  37 bool 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
  56 class MipsPreLegalizerCombiner : public MachineFunctionPass {
  57 public:
  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
  70 void MipsPreLegalizerCombiner::getAnalysisUsage(AnalysisUsage &AU) const {
  71   AU.addRequired<TargetPassConfig>();
  72   AU.setPreservesCFG();
  73   getSelectionDAGFallbackAnalysisUsage(AU);
  74   MachineFunctionPass::getAnalysisUsage(AU);
  75 }
  76
  77 MipsPreLegalizerCombiner::MipsPreLegalizerCombiner() : MachineFunctionPass(ID) {
  78   initializeMipsPreLegalizerCombinerPass(*PassRegistry::getPassRegistry());
  79 }
  80
  81 bool 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
  91 char MipsPreLegalizerCombiner::ID = 0;
  92 INITIALIZE_PASS_BEGIN(MipsPreLegalizerCombiner, DEBUG_TYPE,
  93                       "Combine Mips machine instrs before legalization", false,
  94                       false)
  95 INITIALIZE_PASS_DEPENDENCY(TargetPassConfig)
  96 INITIALIZE_PASS_END(MipsPreLegalizerCombiner, DEBUG_TYPE,
  97                     "Combine Mips machine instrs before legalization", false,
  98                     false)
  99
 100 namespace llvm {
 101 FunctionPass *createMipsPreLegalizeCombiner() {
 102   return new MipsPreLegalizerCombiner();
 103 }
 104 } // end namespace llvm