llvm/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/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/ScalarEvolution.h"
  21 #include "llvm/Analysis/ScalarEvolutionAliasAnalysis.h"
  22 #include "llvm/CodeGen/MachineFunction.h"
  23 #include "llvm/CodeGen/MachineModuleInfo.h"
  24 #include "llvm/CodeGen/MachineOptimizationRemarkEmitter.h"
  25 #include "llvm/CodeGen/Passes.h"
  26 #include "llvm/IR/Dominators.h"
  27 #include "llvm/IR/Function.h"
  28
  29 using namespace llvm;
  30 using namespace ore;
  31
  32 Pass *MachineFunctionPass::createPrinterPass(raw_ostream &O,
  33                                              const std::string &Banner) const {
  34   return createMachineFunctionPrinterPass(O, Banner);
  35 }
  36
  37 bool MachineFunctionPass::runOnFunction(Function &F) {
  38   // Do not codegen any 'available_externally' functions at all, they have
  39   // definitions outside the translation unit.
  40   if (F.hasAvailableExternallyLinkage())
  41     return false;
  42
  43   MachineModuleInfo &MMI = getAnalysis<MachineModuleInfoWrapperPass>().getMMI();
  44   MachineFunction &MF = MMI.getOrCreateMachineFunction(F);
  45
  46   MachineFunctionProperties &MFProps = MF.getProperties();
  47
  48 #ifndef NDEBUG
  49   if (!MFProps.verifyRequiredProperties(RequiredProperties)) {
  50     errs() << "MachineFunctionProperties required by " << getPassName()
  51            << " pass are not met by function " << F.getName() << ".\n"
  52            << "Required properties: ";
  53     RequiredProperties.print(errs());
  54     errs() << "\nCurrent properties: ";
  55     MFProps.print(errs());
  56     errs() << "\n";
  57     llvm_unreachable("MachineFunctionProperties check failed");
  58   }
  59 #endif
  60   // Collect the MI count of the function before the pass.
  61   unsigned CountBefore, CountAfter;
  62
  63   // Check if the user asked for size remarks.
  64   bool ShouldEmitSizeRemarks =
  65       F.getParent()->shouldEmitInstrCountChangedRemark();
  66
  67   // If we want size remarks, collect the number of MachineInstrs in our
  68   // MachineFunction before the pass runs.
  69   if (ShouldEmitSizeRemarks)
  70     CountBefore = MF.getInstructionCount();
  71
  72   bool RV = runOnMachineFunction(MF);
  73
  74   if (ShouldEmitSizeRemarks) {
  75     // We wanted size remarks. Check if there was a change to the number of
  76     // MachineInstrs in the module. Emit a remark if there was a change.
  77     CountAfter = MF.getInstructionCount();
  78     if (CountBefore != CountAfter) {
  79       MachineOptimizationRemarkEmitter MORE(MF, nullptr);
  80       MORE.emit([&]() {
  81         int64_t Delta = static_cast<int64_t>(CountAfter) -
  82                         static_cast<int64_t>(CountBefore);
  83         MachineOptimizationRemarkAnalysis R("size-info", "FunctionMISizeChange",
  84                                             MF.getFunction().getSubprogram(),
  85                                             &MF.front());
  86         R << NV("Pass", getPassName())
  87           << ": Function: " << NV("Function", F.getName()) << ": "
  88           << "MI Instruction count changed from "
  89           << NV("MIInstrsBefore", CountBefore) << " to "
  90           << NV("MIInstrsAfter", CountAfter)
  91           << "; Delta: " << NV("Delta", Delta);
  92         return R;
  93       });
  94     }
  95   }
  96
  97   MFProps.set(SetProperties);
  98   MFProps.reset(ClearedProperties);
  99   return RV;
 100 }
 101
 102 void MachineFunctionPass::getAnalysisUsage(AnalysisUsage &AU) const {
 103   AU.addRequired<MachineModuleInfoWrapperPass>();
 104   AU.addPreserved<MachineModuleInfoWrapperPass>();
 105
 106   // MachineFunctionPass preserves all LLVM IR passes, but there's no
 107   // high-level way to express this. Instead, just list a bunch of
 108   // passes explicitly. This does not include setPreservesCFG,
 109   // because CodeGen overloads that to mean preserving the MachineBasicBlock
 110   // CFG in addition to the LLVM IR CFG.
 111   AU.addPreserved<BasicAAWrapperPass>();
 112   AU.addPreserved<DominanceFrontierWrapperPass>();
 113   AU.addPreserved<DominatorTreeWrapperPass>();
 114   AU.addPreserved<AAResultsWrapperPass>();
 115   AU.addPreserved<GlobalsAAWrapperPass>();
 116   AU.addPreserved<IVUsersWrapperPass>();
 117   AU.addPreserved<LoopInfoWrapperPass>();
 118   AU.addPreserved<MemoryDependenceWrapperPass>();
 119   AU.addPreserved<ScalarEvolutionWrapperPass>();
 120   AU.addPreserved<SCEVAAWrapperPass>();
 121
 122   FunctionPass::getAnalysisUsage(AU);
 123 }