llvm/lib/Transforms/Utils/InstructionNamer.cpp

   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 }