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 
21 using namespace llvm;
22 
23 namespace {
24 void nameInstructions(Function &F) {
25   for (auto &Arg : F.args()) {
26     if (!Arg.hasName())
27       Arg.setName("arg");
28   }
29 
30   for (BasicBlock &BB : F) {
31     if (!BB.hasName())
32       BB.setName("bb");
33 
34     for (Instruction &I : BB) {
35       if (!I.hasName() && !I.getType()->isVoidTy())
36         I.setName("i");
37     }
38   }
39 }
40 
41 } // namespace
42 
43 PreservedAnalyses InstructionNamerPass::run(Function &F,
44                                             FunctionAnalysisManager &FAM) {
45   nameInstructions(F);
46   return PreservedAnalyses::all();
47 }
48