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/Module.h" 30 #include "llvm/IR/PrintPasses.h" 31 32 using namespace llvm; 33 using namespace ore; 34 35 Pass *MachineFunctionPass::createPrinterPass(raw_ostream &O, 36 const std::string &Banner) const { 37 return createMachineFunctionPrinterPass(O, Banner); 38 } 39 40 bool MachineFunctionPass::runOnFunction(Function &F) { 41 // Do not codegen any 'available_externally' functions at all, they have 42 // definitions outside the translation unit. 43 if (F.hasAvailableExternallyLinkage()) 44 return false; 45 46 MachineModuleInfo &MMI = getAnalysis<MachineModuleInfoWrapperPass>().getMMI(); 47 MachineFunction &MF = MMI.getOrCreateMachineFunction(F); 48 49 MachineFunctionProperties &MFProps = MF.getProperties(); 50 51 #ifndef NDEBUG 52 if (!MFProps.verifyRequiredProperties(RequiredProperties)) { 53 errs() << "MachineFunctionProperties required by " << getPassName() 54 << " pass are not met by function " << F.getName() << ".\n" 55 << "Required properties: "; 56 RequiredProperties.print(errs()); 57 errs() << "\nCurrent properties: "; 58 MFProps.print(errs()); 59 errs() << "\n"; 60 llvm_unreachable("MachineFunctionProperties check failed"); 61 } 62 #endif 63 // Collect the MI count of the function before the pass. 64 unsigned CountBefore, CountAfter; 65 66 // Check if the user asked for size remarks. 67 bool ShouldEmitSizeRemarks = 68 F.getParent()->shouldEmitInstrCountChangedRemark(); 69 70 // If we want size remarks, collect the number of MachineInstrs in our 71 // MachineFunction before the pass runs. 72 if (ShouldEmitSizeRemarks) 73 CountBefore = MF.getInstructionCount(); 74 75 // For --print-changed, if the function name is a candidate, save the 76 // serialized MF to be compared later. 77 SmallString<0> BeforeStr, AfterStr; 78 StringRef PassID; 79 if (PrintChanged != ChangePrinter::None) { 80 if (const PassInfo *PI = Pass::lookupPassInfo(getPassID())) 81 PassID = PI->getPassArgument(); 82 } 83 const bool IsInterestingPass = isPassInPrintList(PassID); 84 const bool ShouldPrintChanged = PrintChanged != ChangePrinter::None && 85 IsInterestingPass && 86 isFunctionInPrintList(MF.getName()); 87 if (ShouldPrintChanged) { 88 raw_svector_ostream OS(BeforeStr); 89 MF.print(OS); 90 } 91 92 MFProps.reset(ClearedProperties); 93 94 bool RV = runOnMachineFunction(MF); 95 96 if (ShouldEmitSizeRemarks) { 97 // We wanted size remarks. Check if there was a change to the number of 98 // MachineInstrs in the module. Emit a remark if there was a change. 99 CountAfter = MF.getInstructionCount(); 100 if (CountBefore != CountAfter) { 101 MachineOptimizationRemarkEmitter MORE(MF, nullptr); 102 MORE.emit([&]() { 103 int64_t Delta = static_cast<int64_t>(CountAfter) - 104 static_cast<int64_t>(CountBefore); 105 MachineOptimizationRemarkAnalysis R("size-info", "FunctionMISizeChange", 106 MF.getFunction().getSubprogram(), 107 &MF.front()); 108 R << NV("Pass", getPassName()) 109 << ": Function: " << NV("Function", F.getName()) << ": " 110 << "MI Instruction count changed from " 111 << NV("MIInstrsBefore", CountBefore) << " to " 112 << NV("MIInstrsAfter", CountAfter) 113 << "; Delta: " << NV("Delta", Delta); 114 return R; 115 }); 116 } 117 } 118 119 MFProps.set(SetProperties); 120 121 // For --print-changed, print if the serialized MF has changed. Modes other 122 // than quiet/verbose are unimplemented and treated the same as 'quiet'. 123 if (ShouldPrintChanged || !IsInterestingPass) { 124 if (ShouldPrintChanged) { 125 raw_svector_ostream OS(AfterStr); 126 MF.print(OS); 127 } 128 if (IsInterestingPass && BeforeStr != AfterStr) { 129 errs() << ("*** IR Dump After " + getPassName() + " (" + PassID + 130 ") on " + MF.getName() + " ***\n"); 131 switch (PrintChanged) { 132 case ChangePrinter::None: 133 llvm_unreachable(""); 134 case ChangePrinter::Quiet: 135 case ChangePrinter::Verbose: 136 case ChangePrinter::DotCfgQuiet: // unimplemented 137 case ChangePrinter::DotCfgVerbose: // unimplemented 138 errs() << AfterStr; 139 break; 140 case ChangePrinter::DiffQuiet: 141 case ChangePrinter::DiffVerbose: 142 case ChangePrinter::ColourDiffQuiet: 143 case ChangePrinter::ColourDiffVerbose: { 144 bool Color = llvm::is_contained( 145 {ChangePrinter::ColourDiffQuiet, ChangePrinter::ColourDiffVerbose}, 146 PrintChanged.getValue()); 147 StringRef Removed = Color ? "\033[31m-%l\033[0m\n" : "-%l\n"; 148 StringRef Added = Color ? "\033[32m+%l\033[0m\n" : "+%l\n"; 149 StringRef NoChange = " %l\n"; 150 errs() << doSystemDiff(BeforeStr, AfterStr, Removed, Added, NoChange); 151 break; 152 } 153 } 154 } else if (llvm::is_contained({ChangePrinter::Verbose, 155 ChangePrinter::DiffVerbose, 156 ChangePrinter::ColourDiffVerbose}, 157 PrintChanged.getValue())) { 158 const char *Reason = 159 IsInterestingPass ? " omitted because no change" : " filtered out"; 160 errs() << "*** IR Dump After " << getPassName(); 161 if (!PassID.empty()) 162 errs() << " (" << PassID << ")"; 163 errs() << " on " << MF.getName() + Reason + " ***\n"; 164 } 165 } 166 return RV; 167 } 168 169 void MachineFunctionPass::getAnalysisUsage(AnalysisUsage &AU) const { 170 AU.addRequired<MachineModuleInfoWrapperPass>(); 171 AU.addPreserved<MachineModuleInfoWrapperPass>(); 172 173 // MachineFunctionPass preserves all LLVM IR passes, but there's no 174 // high-level way to express this. Instead, just list a bunch of 175 // passes explicitly. This does not include setPreservesCFG, 176 // because CodeGen overloads that to mean preserving the MachineBasicBlock 177 // CFG in addition to the LLVM IR CFG. 178 AU.addPreserved<BasicAAWrapperPass>(); 179 AU.addPreserved<DominanceFrontierWrapperPass>(); 180 AU.addPreserved<DominatorTreeWrapperPass>(); 181 AU.addPreserved<AAResultsWrapperPass>(); 182 AU.addPreserved<GlobalsAAWrapperPass>(); 183 AU.addPreserved<IVUsersWrapperPass>(); 184 AU.addPreserved<LoopInfoWrapperPass>(); 185 AU.addPreserved<MemoryDependenceWrapperPass>(); 186 AU.addPreserved<ScalarEvolutionWrapperPass>(); 187 AU.addPreserved<SCEVAAWrapperPass>(); 188 189 FunctionPass::getAnalysisUsage(AU); 190 } 191