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/GlobalISel/MIPatternMatch.h" 21 #include "llvm/CodeGen/MachineFunctionPass.h" 22 #include "llvm/CodeGen/TargetPassConfig.h" 23 #include "llvm/InitializePasses.h" 24 25 #define DEBUG_TYPE "mips-prelegalizer-combiner" 26 27 using namespace llvm; 28 29 namespace { 30 struct MipsPreLegalizerCombinerInfo : public CombinerInfo { 31 public: 32 MipsPreLegalizerCombinerInfo() 33 : CombinerInfo(/*AllowIllegalOps*/ true, /*ShouldLegalizeIllegal*/ false, 34 /*LegalizerInfo*/ nullptr, /*EnableOpt*/ false, 35 /*EnableOptSize*/ false, /*EnableMinSize*/ false) {} 36 }; 37 38 class MipsPreLegalizerCombinerImpl : public Combiner { 39 protected: 40 const MipsSubtarget &STI; 41 // TODO: Make CombinerHelper methods const. 42 mutable CombinerHelper Helper; 43 44 public: 45 MipsPreLegalizerCombinerImpl(MachineFunction &MF, CombinerInfo &CInfo, 46 const TargetPassConfig *TPC, GISelKnownBits &KB, 47 GISelCSEInfo *CSEInfo, const MipsSubtarget &STI, 48 MachineDominatorTree *MDT, 49 const LegalizerInfo *LI) 50 : Combiner(MF, CInfo, TPC, &KB, CSEInfo), STI(STI), 51 Helper(Observer, B, /*IsPreLegalize*/ true, &KB, MDT, LI) {} 52 53 static const char *getName() { return "MipsPreLegalizerCombiner"; } 54 55 void setupGeneratedPerFunctionState(MachineFunction &MF) override { 56 // TODO: TableGen-erate this class' impl. 57 } 58 59 bool tryCombineAll(MachineInstr &MI) const override { 60 61 switch (MI.getOpcode()) { 62 default: 63 return false; 64 case TargetOpcode::G_MEMCPY_INLINE: 65 return Helper.tryEmitMemcpyInline(MI); 66 case TargetOpcode::G_LOAD: 67 case TargetOpcode::G_SEXTLOAD: 68 case TargetOpcode::G_ZEXTLOAD: { 69 // Don't attempt to combine non power of 2 loads or unaligned loads when 70 // subtarget doesn't support them. 71 auto MMO = *MI.memoperands_begin(); 72 const MipsSubtarget &STI = MI.getMF()->getSubtarget<MipsSubtarget>(); 73 if (!MMO->getSize().hasValue() || 74 !isPowerOf2_64(MMO->getSize().getValue())) 75 return false; 76 bool isUnaligned = MMO->getAlign() < MMO->getSize().getValue(); 77 if (!STI.systemSupportsUnalignedAccess() && isUnaligned) 78 return false; 79 80 return Helper.tryCombineExtendingLoads(MI); 81 } 82 } 83 84 return false; 85 } 86 }; 87 88 // Pass boilerplate 89 // ================ 90 91 class MipsPreLegalizerCombiner : public MachineFunctionPass { 92 public: 93 static char ID; 94 95 MipsPreLegalizerCombiner(); 96 97 StringRef getPassName() const override { return "MipsPreLegalizerCombiner"; } 98 99 bool runOnMachineFunction(MachineFunction &MF) override; 100 101 void getAnalysisUsage(AnalysisUsage &AU) const override; 102 }; 103 } // end anonymous namespace 104 105 void MipsPreLegalizerCombiner::getAnalysisUsage(AnalysisUsage &AU) const { 106 AU.addRequired<TargetPassConfig>(); 107 AU.addRequired<GISelKnownBitsAnalysis>(); 108 AU.addPreserved<GISelKnownBitsAnalysis>(); 109 AU.setPreservesCFG(); 110 getSelectionDAGFallbackAnalysisUsage(AU); 111 MachineFunctionPass::getAnalysisUsage(AU); 112 } 113 114 MipsPreLegalizerCombiner::MipsPreLegalizerCombiner() : MachineFunctionPass(ID) { 115 initializeMipsPreLegalizerCombinerPass(*PassRegistry::getPassRegistry()); 116 } 117 118 bool MipsPreLegalizerCombiner::runOnMachineFunction(MachineFunction &MF) { 119 if (MF.getProperties().hasProperty( 120 MachineFunctionProperties::Property::FailedISel)) 121 return false; 122 123 auto *TPC = &getAnalysis<TargetPassConfig>(); 124 const MipsSubtarget &ST = MF.getSubtarget<MipsSubtarget>(); 125 const MipsLegalizerInfo *LI = 126 static_cast<const MipsLegalizerInfo *>(ST.getLegalizerInfo()); 127 128 GISelKnownBits *KB = &getAnalysis<GISelKnownBitsAnalysis>().get(MF); 129 MipsPreLegalizerCombinerInfo PCInfo; 130 MipsPreLegalizerCombinerImpl Impl(MF, PCInfo, TPC, *KB, /*CSEInfo*/ nullptr, 131 ST, /*MDT*/ nullptr, LI); 132 return Impl.combineMachineInstrs(); 133 } 134 135 char MipsPreLegalizerCombiner::ID = 0; 136 INITIALIZE_PASS_BEGIN(MipsPreLegalizerCombiner, DEBUG_TYPE, 137 "Combine Mips machine instrs before legalization", false, 138 false) 139 INITIALIZE_PASS_DEPENDENCY(TargetPassConfig) 140 INITIALIZE_PASS_DEPENDENCY(GISelKnownBitsAnalysis) 141 INITIALIZE_PASS_END(MipsPreLegalizerCombiner, DEBUG_TYPE, 142 "Combine Mips machine instrs before legalization", false, 143 false) 144 145 namespace llvm { 146 FunctionPass *createMipsPreLegalizeCombiner() { 147 return new MipsPreLegalizerCombiner(); 148 } 149 } // end namespace llvm 150