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/CodeGen/MachineFunctionPass.h"
  22 #include "llvm/InitializePasses.h"
  23
  24 using namespace llvm;
  25
  26 namespace llvm {
  27 extern char &MIRNamerID;
  28 } // namespace llvm
  29
  30 #define DEBUG_TYPE "mir-namer"
  31
  32 namespace {
  33
  34 class MIRNamer : public MachineFunctionPass {
  35 public:
  36   static char ID;
  37   MIRNamer() : MachineFunctionPass(ID) {}
  38
  39   StringRef getPassName() const override {
  40     return "Rename virtual register operands";
  41   }
  42
  43   void getAnalysisUsage(AnalysisUsage &AU) const override {
  44     AU.setPreservesCFG();
  45     MachineFunctionPass::getAnalysisUsage(AU);
  46   }
  47
  48   bool runOnMachineFunction(MachineFunction &MF) override {
  49     bool Changed = false;
  50
  51     if (MF.empty())
  52       return Changed;
  53
  54     VRegRenamer Renamer(MF.getRegInfo());
  55
  56     unsigned BBIndex = 0;
  57     ReversePostOrderTraversal<MachineBasicBlock *> RPOT(&*MF.begin());
  58     for (auto &MBB : RPOT)
  59       Changed |= Renamer.renameVRegs(MBB, BBIndex++);
  60
  61     return Changed;
  62   }
  63 };
  64
  65 } // end anonymous namespace
  66
  67 char MIRNamer::ID;
  68
  69 char &llvm::MIRNamerID = MIRNamer::ID;
  70
  71 INITIALIZE_PASS_BEGIN(MIRNamer, "mir-namer", "Rename Register Operands", false,
  72                       false)
  73
  74 INITIALIZE_PASS_END(MIRNamer, "mir-namer", "Rename Register Operands", false,
  75                     false)