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 (!isPowerOf2_64(MMO->getSize())) 74 return false; 75 bool isUnaligned = MMO->getAlign() < MMO->getSize(); 76 if (!STI.systemSupportsUnalignedAccess() && isUnaligned) 77 return false; 78 79 return Helper.tryCombineExtendingLoads(MI); 80 } 81 } 82 83 return false; 84 } 85 }; 86 87 // Pass boilerplate 88 // ================ 89 90 class MipsPreLegalizerCombiner : public MachineFunctionPass { 91 public: 92 static char ID; 93 94 MipsPreLegalizerCombiner(); 95 96 StringRef getPassName() const override { return "MipsPreLegalizerCombiner"; } 97 98 bool runOnMachineFunction(MachineFunction &MF) override; 99 100 void getAnalysisUsage(AnalysisUsage &AU) const override; 101 }; 102 } // end anonymous namespace 103 104 void MipsPreLegalizerCombiner::getAnalysisUsage(AnalysisUsage &AU) const { 105 AU.addRequired<TargetPassConfig>(); 106 AU.addRequired<GISelKnownBitsAnalysis>(); 107 AU.addPreserved<GISelKnownBitsAnalysis>(); 108 AU.setPreservesCFG(); 109 getSelectionDAGFallbackAnalysisUsage(AU); 110 MachineFunctionPass::getAnalysisUsage(AU); 111 } 112 113 MipsPreLegalizerCombiner::MipsPreLegalizerCombiner() : MachineFunctionPass(ID) { 114 initializeMipsPreLegalizerCombinerPass(*PassRegistry::getPassRegistry()); 115 } 116 117 bool MipsPreLegalizerCombiner::runOnMachineFunction(MachineFunction &MF) { 118 if (MF.getProperties().hasProperty( 119 MachineFunctionProperties::Property::FailedISel)) 120 return false; 121 122 auto *TPC = &getAnalysis<TargetPassConfig>(); 123 const MipsSubtarget &ST = MF.getSubtarget<MipsSubtarget>(); 124 const MipsLegalizerInfo *LI = 125 static_cast<const MipsLegalizerInfo *>(ST.getLegalizerInfo()); 126 127 GISelKnownBits *KB = &getAnalysis<GISelKnownBitsAnalysis>().get(MF); 128 MipsPreLegalizerCombinerInfo PCInfo; 129 MipsPreLegalizerCombinerImpl Impl(MF, PCInfo, TPC, *KB, /*CSEInfo*/ nullptr, 130 ST, /*MDT*/ nullptr, LI); 131 return Impl.combineMachineInstrs(); 132 } 133 134 char MipsPreLegalizerCombiner::ID = 0; 135 INITIALIZE_PASS_BEGIN(MipsPreLegalizerCombiner, DEBUG_TYPE, 136 "Combine Mips machine instrs before legalization", false, 137 false) 138 INITIALIZE_PASS_DEPENDENCY(TargetPassConfig) 139 INITIALIZE_PASS_DEPENDENCY(GISelKnownBitsAnalysis) 140 INITIALIZE_PASS_END(MipsPreLegalizerCombiner, DEBUG_TYPE, 141 "Combine Mips machine instrs before legalization", false, 142 false) 143 144 namespace llvm { 145 FunctionPass *createMipsPreLegalizeCombiner() { 146 return new MipsPreLegalizerCombiner(); 147 } 148 } // end namespace llvm 149