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/BasicAliasAnalysis.h" 15 #include "llvm/Analysis/DominanceFrontier.h" 16 #include "llvm/Analysis/GlobalsModRef.h" 17 #include "llvm/Analysis/IVUsers.h" 18 #include "llvm/Analysis/LoopInfo.h" 19 #include "llvm/Analysis/MemoryDependenceAnalysis.h" 20 #include "llvm/Analysis/OptimizationRemarkEmitter.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 #include "llvm/IR/PrintPasses.h" 30 31 using namespace llvm; 32 using namespace ore; 33 34 Pass *MachineFunctionPass::createPrinterPass(raw_ostream &O, 35 const std::string &Banner) const { 36 return createMachineFunctionPrinterPass(O, Banner); 37 } 38 39 bool MachineFunctionPass::runOnFunction(Function &F) { 40 // Do not codegen any 'available_externally' functions at all, they have 41 // definitions outside the translation unit. 42 if (F.hasAvailableExternallyLinkage()) 43 return false; 44 45 MachineModuleInfo &MMI = getAnalysis<MachineModuleInfoWrapperPass>().getMMI(); 46 MachineFunction &MF = MMI.getOrCreateMachineFunction(F); 47 48 MachineFunctionProperties &MFProps = MF.getProperties(); 49 50 #ifndef NDEBUG 51 if (!MFProps.verifyRequiredProperties(RequiredProperties)) { 52 errs() << "MachineFunctionProperties required by " << getPassName() 53 << " pass are not met by function " << F.getName() << ".\n" 54 << "Required properties: "; 55 RequiredProperties.print(errs()); 56 errs() << "\nCurrent properties: "; 57 MFProps.print(errs()); 58 errs() << "\n"; 59 llvm_unreachable("MachineFunctionProperties check failed"); 60 } 61 #endif 62 // Collect the MI count of the function before the pass. 63 unsigned CountBefore, CountAfter; 64 65 // Check if the user asked for size remarks. 66 bool ShouldEmitSizeRemarks = 67 F.getParent()->shouldEmitInstrCountChangedRemark(); 68 69 // If we want size remarks, collect the number of MachineInstrs in our 70 // MachineFunction before the pass runs. 71 if (ShouldEmitSizeRemarks) 72 CountBefore = MF.getInstructionCount(); 73 74 // For --print-changed, if the function name is a candidate, save the 75 // serialized MF to be compared later. 76 SmallString<0> BeforeStr, AfterStr; 77 StringRef PassID; 78 if (const PassInfo *PI = Pass::lookupPassInfo(getPassID())) 79 PassID = PI->getPassArgument(); 80 const bool IsInterestingPass = isPassInPrintList(PassID); 81 const bool ShouldPrintChanged = PrintChanged != ChangePrinter::None && 82 IsInterestingPass && 83 isFunctionInPrintList(MF.getName()); 84 if (ShouldPrintChanged) { 85 raw_svector_ostream OS(BeforeStr); 86 MF.print(OS); 87 } 88 89 bool RV = runOnMachineFunction(MF); 90 91 if (ShouldEmitSizeRemarks) { 92 // We wanted size remarks. Check if there was a change to the number of 93 // MachineInstrs in the module. Emit a remark if there was a change. 94 CountAfter = MF.getInstructionCount(); 95 if (CountBefore != CountAfter) { 96 MachineOptimizationRemarkEmitter MORE(MF, nullptr); 97 MORE.emit([&]() { 98 int64_t Delta = static_cast<int64_t>(CountAfter) - 99 static_cast<int64_t>(CountBefore); 100 MachineOptimizationRemarkAnalysis R("size-info", "FunctionMISizeChange", 101 MF.getFunction().getSubprogram(), 102 &MF.front()); 103 R << NV("Pass", getPassName()) 104 << ": Function: " << NV("Function", F.getName()) << ": " 105 << "MI Instruction count changed from " 106 << NV("MIInstrsBefore", CountBefore) << " to " 107 << NV("MIInstrsAfter", CountAfter) 108 << "; Delta: " << NV("Delta", Delta); 109 return R; 110 }); 111 } 112 } 113 114 MFProps.set(SetProperties); 115 MFProps.reset(ClearedProperties); 116 117 // For --print-changed, print if the serialized MF has changed. Modes other 118 // than quiet/verbose are unimplemented and treated the same as 'quiet'. 119 if (ShouldPrintChanged || !IsInterestingPass) { 120 if (ShouldPrintChanged) { 121 raw_svector_ostream OS(AfterStr); 122 MF.print(OS); 123 } 124 if (IsInterestingPass && BeforeStr != AfterStr) { 125 errs() << ("*** IR Dump After " + getPassName() + " (" + PassID + 126 ") on " + MF.getName() + " ***\n"); 127 switch (PrintChanged) { 128 case ChangePrinter::None: 129 llvm_unreachable(""); 130 case ChangePrinter::Quiet: 131 case ChangePrinter::Verbose: 132 case ChangePrinter::DotCfgQuiet: // unimplemented 133 case ChangePrinter::DotCfgVerbose: // unimplemented 134 errs() << AfterStr; 135 break; 136 case ChangePrinter::DiffQuiet: 137 case ChangePrinter::DiffVerbose: 138 case ChangePrinter::ColourDiffQuiet: 139 case ChangePrinter::ColourDiffVerbose: { 140 bool Color = llvm::is_contained( 141 {ChangePrinter::ColourDiffQuiet, ChangePrinter::ColourDiffVerbose}, 142 PrintChanged.getValue()); 143 StringRef Removed = Color ? "\033[31m-%l\033[0m\n" : "-%l\n"; 144 StringRef Added = Color ? "\033[32m+%l\033[0m\n" : "+%l\n"; 145 StringRef NoChange = " %l\n"; 146 errs() << doSystemDiff(BeforeStr, AfterStr, Removed, Added, NoChange); 147 break; 148 } 149 } 150 } else if (llvm::is_contained({ChangePrinter::Verbose, 151 ChangePrinter::DiffVerbose, 152 ChangePrinter::ColourDiffVerbose}, 153 PrintChanged.getValue())) { 154 const char *Reason = 155 IsInterestingPass ? " omitted because no change" : " filtered out"; 156 errs() << "*** IR Dump After " << getPassName(); 157 if (!PassID.empty()) 158 errs() << " (" << PassID << ")"; 159 errs() << " on " << MF.getName() + Reason + " ***\n"; 160 } 161 } 162 return RV; 163 } 164 165 void MachineFunctionPass::getAnalysisUsage(AnalysisUsage &AU) const { 166 AU.addRequired<MachineModuleInfoWrapperPass>(); 167 AU.addPreserved<MachineModuleInfoWrapperPass>(); 168 169 // MachineFunctionPass preserves all LLVM IR passes, but there's no 170 // high-level way to express this. Instead, just list a bunch of 171 // passes explicitly. This does not include setPreservesCFG, 172 // because CodeGen overloads that to mean preserving the MachineBasicBlock 173 // CFG in addition to the LLVM IR CFG. 174 AU.addPreserved<BasicAAWrapperPass>(); 175 AU.addPreserved<DominanceFrontierWrapperPass>(); 176 AU.addPreserved<DominatorTreeWrapperPass>(); 177 AU.addPreserved<AAResultsWrapperPass>(); 178 AU.addPreserved<GlobalsAAWrapperPass>(); 179 AU.addPreserved<IVUsersWrapperPass>(); 180 AU.addPreserved<LoopInfoWrapperPass>(); 181 AU.addPreserved<MemoryDependenceWrapperPass>(); 182 AU.addPreserved<ScalarEvolutionWrapperPass>(); 183 AU.addPreserved<SCEVAAWrapperPass>(); 184 185 FunctionPass::getAnalysisUsage(AU); 186 } 187