1//===- InstructionNamer.cpp - Give anonymous instructions names -----------===//
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 is a little utility pass that gives instructions names, this is mostly
10// useful when diffing the effect of an optimization because deleting an
11// unnamed instruction can change all other instruction numbering, making the
12// diff very noisy.
13//
14//===----------------------------------------------------------------------===//
15
16#include "llvm/Transforms/Utils/InstructionNamer.h"
17#include "llvm/IR/Function.h"
18#include "llvm/IR/PassManager.h"
19#include "llvm/IR/Type.h"
20#include "llvm/InitializePasses.h"
21#include "llvm/Pass.h"
22#include "llvm/Transforms/Utils.h"
23
24using namespace llvm;
25
26namespace {
27void nameInstructions(Function &F) {
28  for (auto &Arg : F.args()) {
29    if (!Arg.hasName())
30      Arg.setName("arg");
31  }
32
33  for (BasicBlock &BB : F) {
34    if (!BB.hasName())
35      BB.setName("bb");
36
37    for (Instruction &I : BB) {
38      if (!I.hasName() && !I.getType()->isVoidTy())
39        I.setName("i");
40    }
41  }
42}
43
44struct InstNamer : public FunctionPass {
45  static char ID; // Pass identification, replacement for typeid
46  InstNamer() : FunctionPass(ID) {
47    initializeInstNamerPass(*PassRegistry::getPassRegistry());
48  }
49
50  void getAnalysisUsage(AnalysisUsage &Info) const override {
51    Info.setPreservesAll();
52  }
53
54  bool runOnFunction(Function &F) override {
55    nameInstructions(F);
56    return true;
57  }
58};
59
60  char InstNamer::ID = 0;
61  } // namespace
62
63INITIALIZE_PASS(InstNamer, "instnamer",
64                "Assign names to anonymous instructions", false, false)
65char &llvm::InstructionNamerID = InstNamer::ID;
66//===----------------------------------------------------------------------===//
67//
68// InstructionNamer - Give any unnamed non-void instructions "tmp" names.
69//
70FunctionPass *llvm::createInstructionNamerPass() {
71  return new InstNamer();
72}
73
74PreservedAnalyses InstructionNamerPass::run(Function &F,
75                                            FunctionAnalysisManager &FAM) {
76  nameInstructions(F);
77  return PreservedAnalyses::all();
78}
79