206 lines · cpp
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-exception6//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/DroppedVariableStatsMIR.h"24#include "llvm/CodeGen/MachineFunction.h"25#include "llvm/CodeGen/MachineModuleInfo.h"26#include "llvm/CodeGen/MachineOptimizationRemarkEmitter.h"27#include "llvm/CodeGen/Passes.h"28#include "llvm/IR/Dominators.h"29#include "llvm/IR/Function.h"30#include "llvm/IR/Module.h"31#include "llvm/IR/PrintPasses.h"32 33using namespace llvm;34using namespace ore;35 36static cl::opt<bool> DroppedVarStatsMIR(37 "dropped-variable-stats-mir", cl::Hidden,38 cl::desc("Dump dropped debug variables stats for MIR passes"),39 cl::init(false));40 41Pass *MachineFunctionPass::createPrinterPass(raw_ostream &O,42 const std::string &Banner) const {43 return createMachineFunctionPrinterPass(O, Banner);44}45 46bool MachineFunctionPass::runOnFunction(Function &F) {47 // Do not codegen any 'available_externally' functions at all, they have48 // definitions outside the translation unit.49 if (F.hasAvailableExternallyLinkage())50 return false;51 52 MachineModuleInfo &MMI = getAnalysis<MachineModuleInfoWrapperPass>().getMMI();53 MachineFunction &MF = MMI.getOrCreateMachineFunction(F);54 55 MachineFunctionProperties &MFProps = MF.getProperties();56 57#ifndef NDEBUG58 if (!MFProps.verifyRequiredProperties(RequiredProperties)) {59 errs() << "MachineFunctionProperties required by " << getPassName()60 << " pass are not met by function " << F.getName() << ".\n"61 << "Required properties: ";62 RequiredProperties.print(errs());63 errs() << "\nCurrent properties: ";64 MFProps.print(errs());65 errs() << "\n";66 llvm_unreachable("MachineFunctionProperties check failed");67 }68#endif69 // Collect the MI count of the function before the pass.70 unsigned CountBefore, CountAfter;71 72 // Check if the user asked for size remarks.73 bool ShouldEmitSizeRemarks =74 F.getParent()->shouldEmitInstrCountChangedRemark();75 76 // If we want size remarks, collect the number of MachineInstrs in our77 // MachineFunction before the pass runs.78 if (ShouldEmitSizeRemarks)79 CountBefore = MF.getInstructionCount();80 81 // For --print-changed, if the function name is a candidate, save the82 // serialized MF to be compared later.83 SmallString<0> BeforeStr, AfterStr;84 StringRef PassID;85 if (PrintChanged != ChangePrinter::None) {86 if (const PassInfo *PI = Pass::lookupPassInfo(getPassID()))87 PassID = PI->getPassArgument();88 }89 const bool IsInterestingPass = isPassInPrintList(PassID);90 const bool ShouldPrintChanged = PrintChanged != ChangePrinter::None &&91 IsInterestingPass &&92 isFunctionInPrintList(MF.getName());93 if (ShouldPrintChanged) {94 raw_svector_ostream OS(BeforeStr);95 MF.print(OS);96 }97 98 MFProps.reset(ClearedProperties);99 100 bool RV;101 if (DroppedVarStatsMIR) {102 DroppedVariableStatsMIR DroppedVarStatsMF;103 auto PassName = getPassName();104 DroppedVarStatsMF.runBeforePass(PassName, &MF);105 RV = runOnMachineFunction(MF);106 DroppedVarStatsMF.runAfterPass(PassName, &MF);107 } else {108 RV = runOnMachineFunction(MF);109 }110 111 if (ShouldEmitSizeRemarks) {112 // We wanted size remarks. Check if there was a change to the number of113 // MachineInstrs in the module. Emit a remark if there was a change.114 CountAfter = MF.getInstructionCount();115 if (CountBefore != CountAfter) {116 MachineOptimizationRemarkEmitter MORE(MF, nullptr);117 MORE.emit([&]() {118 int64_t Delta = static_cast<int64_t>(CountAfter) -119 static_cast<int64_t>(CountBefore);120 MachineOptimizationRemarkAnalysis R("size-info", "FunctionMISizeChange",121 MF.getFunction().getSubprogram(),122 &MF.front());123 R << NV("Pass", getPassName())124 << ": Function: " << NV("Function", F.getName()) << ": "125 << "MI Instruction count changed from "126 << NV("MIInstrsBefore", CountBefore) << " to "127 << NV("MIInstrsAfter", CountAfter)128 << "; Delta: " << NV("Delta", Delta);129 return R;130 });131 }132 }133 134 MFProps.set(SetProperties);135 136 // For --print-changed, print if the serialized MF has changed. Modes other137 // than quiet/verbose are unimplemented and treated the same as 'quiet'.138 if (ShouldPrintChanged || !IsInterestingPass) {139 if (ShouldPrintChanged) {140 raw_svector_ostream OS(AfterStr);141 MF.print(OS);142 }143 if (IsInterestingPass && BeforeStr != AfterStr) {144 errs() << ("*** IR Dump After " + getPassName() + " (" + PassID +145 ") on " + MF.getName() + " ***\n");146 switch (PrintChanged) {147 case ChangePrinter::None:148 llvm_unreachable("");149 case ChangePrinter::Quiet:150 case ChangePrinter::Verbose:151 case ChangePrinter::DotCfgQuiet: // unimplemented152 case ChangePrinter::DotCfgVerbose: // unimplemented153 errs() << AfterStr;154 break;155 case ChangePrinter::DiffQuiet:156 case ChangePrinter::DiffVerbose:157 case ChangePrinter::ColourDiffQuiet:158 case ChangePrinter::ColourDiffVerbose: {159 bool Color = llvm::is_contained(160 {ChangePrinter::ColourDiffQuiet, ChangePrinter::ColourDiffVerbose},161 PrintChanged.getValue());162 StringRef Removed = Color ? "\033[31m-%l\033[0m\n" : "-%l\n";163 StringRef Added = Color ? "\033[32m+%l\033[0m\n" : "+%l\n";164 StringRef NoChange = " %l\n";165 errs() << doSystemDiff(BeforeStr, AfterStr, Removed, Added, NoChange);166 break;167 }168 }169 } else if (llvm::is_contained({ChangePrinter::Verbose,170 ChangePrinter::DiffVerbose,171 ChangePrinter::ColourDiffVerbose},172 PrintChanged.getValue())) {173 const char *Reason =174 IsInterestingPass ? " omitted because no change" : " filtered out";175 errs() << "*** IR Dump After " << getPassName();176 if (!PassID.empty())177 errs() << " (" << PassID << ")";178 errs() << " on " << MF.getName() + Reason + " ***\n";179 }180 }181 return RV;182}183 184void MachineFunctionPass::getAnalysisUsage(AnalysisUsage &AU) const {185 AU.addRequired<MachineModuleInfoWrapperPass>();186 AU.addPreserved<MachineModuleInfoWrapperPass>();187 188 // MachineFunctionPass preserves all LLVM IR passes, but there's no189 // high-level way to express this. Instead, just list a bunch of190 // passes explicitly. This does not include setPreservesCFG,191 // because CodeGen overloads that to mean preserving the MachineBasicBlock192 // CFG in addition to the LLVM IR CFG.193 AU.addPreserved<BasicAAWrapperPass>();194 AU.addPreserved<DominanceFrontierWrapperPass>();195 AU.addPreserved<DominatorTreeWrapperPass>();196 AU.addPreserved<AAResultsWrapperPass>();197 AU.addPreserved<GlobalsAAWrapperPass>();198 AU.addPreserved<IVUsersWrapperPass>();199 AU.addPreserved<LoopInfoWrapperPass>();200 AU.addPreserved<MemoryDependenceWrapperPass>();201 AU.addPreserved<ScalarEvolutionWrapperPass>();202 AU.addPreserved<SCEVAAWrapperPass>();203 204 FunctionPass::getAnalysisUsage(AU);205}206