llvm/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 #include "llvm/InitializePasses.h"
  27
  28 using namespace llvm;
  29
  30 namespace llvm {
  31 extern char &MIRNamerID;
  32 } // namespace llvm
  33
  34 #define DEBUG_TYPE "mir-namer"
  35
  36 namespace {
  37
  38 class MIRNamer : public MachineFunctionPass {
  39 public:
  40   static char ID;
  41   MIRNamer() : MachineFunctionPass(ID) {}
  42
  43   StringRef getPassName() const override {
  44     return "Rename virtual register operands";
  45   }
  46
  47   void getAnalysisUsage(AnalysisUsage &AU) const override {
  48     AU.setPreservesCFG();
  49     MachineFunctionPass::getAnalysisUsage(AU);
  50   }
  51
  52   bool runOnMachineFunction(MachineFunction &MF) override {
  53     bool Changed = false;
  54
  55     if (MF.empty())
  56       return Changed;
  57
  58     VRegRenamer Renamer(MF.getRegInfo());
  59
  60     unsigned BBIndex = 0;
  61     ReversePostOrderTraversal<MachineBasicBlock *> RPOT(&*MF.begin());
  62     for (auto &MBB : RPOT)
  63       Changed |= Renamer.renameVRegs(MBB, BBIndex++);
  64
  65     return Changed;
  66   }
  67 };
  68
  69 } // end anonymous namespace
  70
  71 char MIRNamer::ID;
  72
  73 char &llvm::MIRNamerID = MIRNamer::ID;
  74
  75 INITIALIZE_PASS_BEGIN(MIRNamer, "mir-namer", "Rename Register Operands", false,
  76                       false)
  77
  78 INITIALIZE_PASS_END(MIRNamer, "mir-namer", "Rename Register Operands", false,
  79                     false)