lib/CodeGen/MachineFunctionPass.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-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<MachineModuleInfo>();
  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<MachineModuleInfo>();
 105   AU.addPreserved<MachineModuleInfo>();
 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 }