contrib/llvm/lib/CodeGen/MachineFunctionPass.cpp

   1 //===-- MachineFunctionPass.cpp -------------------------------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file contains the definitions of the MachineFunctionPass members.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/CodeGen/MachineFunctionPass.h"
  15 #include "llvm/Analysis/AliasAnalysis.h"
  16 #include "llvm/Analysis/BasicAliasAnalysis.h"
  17 #include "llvm/Analysis/DominanceFrontier.h"
  18 #include "llvm/Analysis/GlobalsModRef.h"
  19 #include "llvm/Analysis/IVUsers.h"
  20 #include "llvm/Analysis/LoopInfo.h"
  21 #include "llvm/Analysis/MemoryDependenceAnalysis.h"
  22 #include "llvm/Analysis/ScalarEvolution.h"
  23 #include "llvm/Analysis/ScalarEvolutionAliasAnalysis.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
  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<MachineModuleInfo>();
  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   bool RV = runOnMachineFunction(MF);
  75
  76   if (ShouldEmitSizeRemarks) {
  77     // We wanted size remarks. Check if there was a change to the number of
  78     // MachineInstrs in the module. Emit a remark if there was a change.
  79     CountAfter = MF.getInstructionCount();
  80     if (CountBefore != CountAfter) {
  81       MachineOptimizationRemarkEmitter MORE(MF, nullptr);
  82       MORE.emit([&]() {
  83         int64_t Delta = static_cast<int64_t>(CountAfter) -
  84                         static_cast<int64_t>(CountBefore);
  85         MachineOptimizationRemarkAnalysis R("size-info", "FunctionMISizeChange",
  86                                             MF.getFunction().getSubprogram(),
  87                                             &MF.front());
  88         R << NV("Pass", getPassName())
  89           << ": Function: " << NV("Function", F.getName()) << ": "
  90           << "MI Instruction count changed from "
  91           << NV("MIInstrsBefore", CountBefore) << " to "
  92           << NV("MIInstrsAfter", CountAfter)
  93           << "; Delta: " << NV("Delta", Delta);
  94         return R;
  95       });
  96     }
  97   }
  98
  99   MFProps.set(SetProperties);
 100   MFProps.reset(ClearedProperties);
 101   return RV;
 102 }
 103
 104 void MachineFunctionPass::getAnalysisUsage(AnalysisUsage &AU) const {
 105   AU.addRequired<MachineModuleInfo>();
 106   AU.addPreserved<MachineModuleInfo>();
 107
 108   // MachineFunctionPass preserves all LLVM IR passes, but there's no
 109   // high-level way to express this. Instead, just list a bunch of
 110   // passes explicitly. This does not include setPreservesCFG,
 111   // because CodeGen overloads that to mean preserving the MachineBasicBlock
 112   // CFG in addition to the LLVM IR CFG.
 113   AU.addPreserved<BasicAAWrapperPass>();
 114   AU.addPreserved<DominanceFrontierWrapperPass>();
 115   AU.addPreserved<DominatorTreeWrapperPass>();
 116   AU.addPreserved<AAResultsWrapperPass>();
 117   AU.addPreserved<GlobalsAAWrapperPass>();
 118   AU.addPreserved<IVUsersWrapperPass>();
 119   AU.addPreserved<LoopInfoWrapperPass>();
 120   AU.addPreserved<MemoryDependenceWrapperPass>();
 121   AU.addPreserved<ScalarEvolutionWrapperPass>();
 122   AU.addPreserved<SCEVAAWrapperPass>();
 123
 124   FunctionPass::getAnalysisUsage(AU);
 125 }