lib/CodeGen/MIRNamerPass.cpp

   1 //===----------------------- MIRNamer.cpp - MIR Namer ---------------------===//
   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 // The purpose of this pass is to rename virtual register operands with the goal
  10 // of making it easier to author easier to read tests for MIR. This pass reuses
  11 // the vreg renamer used by MIRCanonicalizerPass.
  12 //
  13 // Basic Usage:
  14 //
  15 // llc -o - -run-pass mir-namer example.mir
  16 //
  17 //===----------------------------------------------------------------------===//
  18
  19 #include "MIRVRegNamerUtils.h"
  20 #include "llvm/ADT/PostOrderIterator.h"
  21 #include "llvm/ADT/STLExtras.h"
  22 #include "llvm/CodeGen/MachineFunctionPass.h"
  23 #include "llvm/CodeGen/MachineInstrBuilder.h"
  24 #include "llvm/CodeGen/MachineRegisterInfo.h"
  25 #include "llvm/CodeGen/Passes.h"
  26
  27 using namespace llvm;
  28
  29 namespace llvm {
  30 extern char &MIRNamerID;
  31 } // namespace llvm
  32
  33 #define DEBUG_TYPE "mir-namer"
  34
  35 namespace {
  36
  37 class MIRNamer : public MachineFunctionPass {
  38 public:
  39   static char ID;
  40   MIRNamer() : MachineFunctionPass(ID) {}
  41
  42   StringRef getPassName() const override {
  43     return "Rename virtual register operands";
  44   }
  45
  46   void getAnalysisUsage(AnalysisUsage &AU) const override {
  47     AU.setPreservesCFG();
  48     MachineFunctionPass::getAnalysisUsage(AU);
  49   }
  50
  51   bool runOnMachineFunction(MachineFunction &MF) override {
  52     bool Changed = false;
  53
  54     if (MF.empty())
  55       return Changed;
  56
  57     NamedVRegCursor NVC(MF.getRegInfo());
  58
  59     ReversePostOrderTraversal<MachineBasicBlock *> RPOT(&*MF.begin());
  60     for (auto &MBB : RPOT)
  61       Changed |= NVC.renameVRegs(MBB);
  62
  63     return Changed;
  64   }
  65 };
  66
  67 } // end anonymous namespace
  68
  69 char MIRNamer::ID;
  70
  71 char &llvm::MIRNamerID = MIRNamer::ID;
  72
  73 INITIALIZE_PASS_BEGIN(MIRNamer, "mir-namer", "Rename Register Operands", false,
  74                       false)
  75
  76 INITIALIZE_PASS_END(MIRNamer, "mir-namer", "Rename Register Operands", false,
  77                     false)