1 //===-- MachineFunctionPass.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 file contains the definitions of the MachineFunctionPass members. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #include "llvm/CodeGen/MachineFunctionPass.h" 14 #include "llvm/Analysis/AliasAnalysis.h" 15 #include "llvm/Analysis/BasicAliasAnalysis.h" 16 #include "llvm/Analysis/DominanceFrontier.h" 17 #include "llvm/Analysis/GlobalsModRef.h" 18 #include "llvm/Analysis/IVUsers.h" 19 #include "llvm/Analysis/LoopInfo.h" 20 #include "llvm/Analysis/MemoryDependenceAnalysis.h" 21 #include "llvm/Analysis/ScalarEvolution.h" 22 #include "llvm/Analysis/ScalarEvolutionAliasAnalysis.h" 23 #include "llvm/CodeGen/MachineFunction.h" 24 #include "llvm/CodeGen/MachineModuleInfo.h" 25 #include "llvm/CodeGen/MachineOptimizationRemarkEmitter.h" 26 #include "llvm/CodeGen/Passes.h" 27 #include "llvm/IR/Dominators.h" 28 #include "llvm/IR/Function.h" 29 30 using namespace llvm; 31 using namespace ore; 32 33 Pass *MachineFunctionPass::createPrinterPass(raw_ostream &O, 34 const std::string &Banner) const { 35 return createMachineFunctionPrinterPass(O, Banner); 36 } 37 38 bool MachineFunctionPass::runOnFunction(Function &F) { 39 // Do not codegen any 'available_externally' functions at all, they have 40 // definitions outside the translation unit. 41 if (F.hasAvailableExternallyLinkage()) 42 return false; 43 44 MachineModuleInfo &MMI = getAnalysis<MachineModuleInfoWrapperPass>().getMMI(); 45 MachineFunction &MF = MMI.getOrCreateMachineFunction(F); 46 47 MachineFunctionProperties &MFProps = MF.getProperties(); 48 49 #ifndef NDEBUG 50 if (!MFProps.verifyRequiredProperties(RequiredProperties)) { 51 errs() << "MachineFunctionProperties required by " << getPassName() 52 << " pass are not met by function " << F.getName() << ".\n" 53 << "Required properties: "; 54 RequiredProperties.print(errs()); 55 errs() << "\nCurrent properties: "; 56 MFProps.print(errs()); 57 errs() << "\n"; 58 llvm_unreachable("MachineFunctionProperties check failed"); 59 } 60 #endif 61 // Collect the MI count of the function before the pass. 62 unsigned CountBefore, CountAfter; 63 64 // Check if the user asked for size remarks. 65 bool ShouldEmitSizeRemarks = 66 F.getParent()->shouldEmitInstrCountChangedRemark(); 67 68 // If we want size remarks, collect the number of MachineInstrs in our 69 // MachineFunction before the pass runs. 70 if (ShouldEmitSizeRemarks) 71 CountBefore = MF.getInstructionCount(); 72 73 bool RV = runOnMachineFunction(MF); 74 75 if (ShouldEmitSizeRemarks) { 76 // We wanted size remarks. Check if there was a change to the number of 77 // MachineInstrs in the module. Emit a remark if there was a change. 78 CountAfter = MF.getInstructionCount(); 79 if (CountBefore != CountAfter) { 80 MachineOptimizationRemarkEmitter MORE(MF, nullptr); 81 MORE.emit([&]() { 82 int64_t Delta = static_cast<int64_t>(CountAfter) - 83 static_cast<int64_t>(CountBefore); 84 MachineOptimizationRemarkAnalysis R("size-info", "FunctionMISizeChange", 85 MF.getFunction().getSubprogram(), 86 &MF.front()); 87 R << NV("Pass", getPassName()) 88 << ": Function: " << NV("Function", F.getName()) << ": " 89 << "MI Instruction count changed from " 90 << NV("MIInstrsBefore", CountBefore) << " to " 91 << NV("MIInstrsAfter", CountAfter) 92 << "; Delta: " << NV("Delta", Delta); 93 return R; 94 }); 95 } 96 } 97 98 MFProps.set(SetProperties); 99 MFProps.reset(ClearedProperties); 100 return RV; 101 } 102 103 void MachineFunctionPass::getAnalysisUsage(AnalysisUsage &AU) const { 104 AU.addRequired<MachineModuleInfoWrapperPass>(); 105 AU.addPreserved<MachineModuleInfoWrapperPass>(); 106 107 // MachineFunctionPass preserves all LLVM IR passes, but there's no 108 // high-level way to express this. Instead, just list a bunch of 109 // passes explicitly. This does not include setPreservesCFG, 110 // because CodeGen overloads that to mean preserving the MachineBasicBlock 111 // CFG in addition to the LLVM IR CFG. 112 AU.addPreserved<BasicAAWrapperPass>(); 113 AU.addPreserved<DominanceFrontierWrapperPass>(); 114 AU.addPreserved<DominatorTreeWrapperPass>(); 115 AU.addPreserved<AAResultsWrapperPass>(); 116 AU.addPreserved<GlobalsAAWrapperPass>(); 117 AU.addPreserved<IVUsersWrapperPass>(); 118 AU.addPreserved<LoopInfoWrapperPass>(); 119 AU.addPreserved<MemoryDependenceWrapperPass>(); 120 AU.addPreserved<ScalarEvolutionWrapperPass>(); 121 AU.addPreserved<SCEVAAWrapperPass>(); 122 123 FunctionPass::getAnalysisUsage(AU); 124 } 125