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 "MipsLegalizerInfo.h" 15 #include "MipsTargetMachine.h" 16 #include "llvm/CodeGen/GlobalISel/Combiner.h" 17 #include "llvm/CodeGen/GlobalISel/CombinerHelper.h" 18 #include "llvm/CodeGen/GlobalISel/CombinerInfo.h" 19 #include "llvm/CodeGen/GlobalISel/GISelKnownBits.h" 20 #include "llvm/CodeGen/MachineFunctionPass.h" 21 #include "llvm/CodeGen/TargetPassConfig.h" 22 #include "llvm/InitializePasses.h" 23 24 #define DEBUG_TYPE "mips-prelegalizer-combiner" 25 26 using namespace llvm; 27 28 namespace { 29 struct MipsPreLegalizerCombinerInfo : public CombinerInfo { 30 public: 31 MipsPreLegalizerCombinerInfo() 32 : CombinerInfo(/*AllowIllegalOps*/ true, /*ShouldLegalizeIllegal*/ false, 33 /*LegalizerInfo*/ nullptr, /*EnableOpt*/ false, 34 /*EnableOptSize*/ false, /*EnableMinSize*/ false) {} 35 }; 36 37 class MipsPreLegalizerCombinerImpl : public Combiner { 38 protected: 39 const MipsSubtarget &STI; 40 const CombinerHelper Helper; 41 42 public: 43 MipsPreLegalizerCombinerImpl(MachineFunction &MF, CombinerInfo &CInfo, 44 const TargetPassConfig *TPC, GISelKnownBits &KB, 45 GISelCSEInfo *CSEInfo, const MipsSubtarget &STI, 46 MachineDominatorTree *MDT, 47 const LegalizerInfo *LI) 48 : Combiner(MF, CInfo, TPC, &KB, CSEInfo), STI(STI), 49 Helper(Observer, B, /*IsPreLegalize*/ true, &KB, MDT, LI) {} 50 51 static const char *getName() { return "MipsPreLegalizerCombiner"; } 52 53 void setupGeneratedPerFunctionState(MachineFunction &MF) override { 54 // TODO: TableGen-erate this class' impl. 55 } 56 57 bool tryCombineAll(MachineInstr &MI) const override { 58 59 switch (MI.getOpcode()) { 60 default: 61 return false; 62 case TargetOpcode::G_MEMCPY_INLINE: 63 return Helper.tryEmitMemcpyInline(MI); 64 case TargetOpcode::G_LOAD: 65 case TargetOpcode::G_SEXTLOAD: 66 case TargetOpcode::G_ZEXTLOAD: { 67 // Don't attempt to combine non power of 2 loads or unaligned loads when 68 // subtarget doesn't support them. 69 auto MMO = *MI.memoperands_begin(); 70 const MipsSubtarget &STI = MI.getMF()->getSubtarget<MipsSubtarget>(); 71 if (!MMO->getSize().hasValue() || 72 !isPowerOf2_64(MMO->getSize().getValue())) 73 return false; 74 bool isUnaligned = MMO->getAlign() < MMO->getSize().getValue(); 75 if (!STI.systemSupportsUnalignedAccess() && isUnaligned) 76 return false; 77 78 return Helper.tryCombineExtendingLoads(MI); 79 } 80 } 81 82 return false; 83 } 84 }; 85 86 // Pass boilerplate 87 // ================ 88 89 class MipsPreLegalizerCombiner : public MachineFunctionPass { 90 public: 91 static char ID; 92 93 MipsPreLegalizerCombiner(); 94 95 StringRef getPassName() const override { return "MipsPreLegalizerCombiner"; } 96 97 bool runOnMachineFunction(MachineFunction &MF) override; 98 99 void getAnalysisUsage(AnalysisUsage &AU) const override; 100 }; 101 } // end anonymous namespace 102 103 void MipsPreLegalizerCombiner::getAnalysisUsage(AnalysisUsage &AU) const { 104 AU.addRequired<TargetPassConfig>(); 105 AU.addRequired<GISelKnownBitsAnalysis>(); 106 AU.addPreserved<GISelKnownBitsAnalysis>(); 107 AU.setPreservesCFG(); 108 getSelectionDAGFallbackAnalysisUsage(AU); 109 MachineFunctionPass::getAnalysisUsage(AU); 110 } 111 112 MipsPreLegalizerCombiner::MipsPreLegalizerCombiner() : MachineFunctionPass(ID) { 113 initializeMipsPreLegalizerCombinerPass(*PassRegistry::getPassRegistry()); 114 } 115 116 bool MipsPreLegalizerCombiner::runOnMachineFunction(MachineFunction &MF) { 117 if (MF.getProperties().hasProperty( 118 MachineFunctionProperties::Property::FailedISel)) 119 return false; 120 121 auto *TPC = &getAnalysis<TargetPassConfig>(); 122 const MipsSubtarget &ST = MF.getSubtarget<MipsSubtarget>(); 123 const MipsLegalizerInfo *LI = 124 static_cast<const MipsLegalizerInfo *>(ST.getLegalizerInfo()); 125 126 GISelKnownBits *KB = &getAnalysis<GISelKnownBitsAnalysis>().get(MF); 127 MipsPreLegalizerCombinerInfo PCInfo; 128 MipsPreLegalizerCombinerImpl Impl(MF, PCInfo, TPC, *KB, /*CSEInfo*/ nullptr, 129 ST, /*MDT*/ nullptr, LI); 130 return Impl.combineMachineInstrs(); 131 } 132 133 char MipsPreLegalizerCombiner::ID = 0; 134 INITIALIZE_PASS_BEGIN(MipsPreLegalizerCombiner, DEBUG_TYPE, 135 "Combine Mips machine instrs before legalization", false, 136 false) 137 INITIALIZE_PASS_DEPENDENCY(TargetPassConfig) 138 INITIALIZE_PASS_DEPENDENCY(GISelKnownBitsAnalysis) 139 INITIALIZE_PASS_END(MipsPreLegalizerCombiner, DEBUG_TYPE, 140 "Combine Mips machine instrs before legalization", false, 141 false) 142 143 namespace llvm { 144 FunctionPass *createMipsPreLegalizeCombiner() { 145 return new MipsPreLegalizerCombiner(); 146 } 147 } // end namespace llvm 148