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/IR/Function.h"
  17 #include "llvm/IR/Type.h"
  18 #include "llvm/Pass.h"
  19 #include "llvm/Transforms/Utils.h"
  20 using namespace llvm;
  21
  22 namespace {
  23   struct InstNamer : public FunctionPass {
  24     static char ID; // Pass identification, replacement for typeid
  25     InstNamer() : FunctionPass(ID) {
  26       initializeInstNamerPass(*PassRegistry::getPassRegistry());
  27     }
  28
  29     void getAnalysisUsage(AnalysisUsage &Info) const override {
  30       Info.setPreservesAll();
  31     }
  32
  33     bool runOnFunction(Function &F) override {
  34       for (auto &Arg : F.args())
  35         if (!Arg.hasName())
  36           Arg.setName("arg");
  37
  38       for (BasicBlock &BB : F) {
  39         if (!BB.hasName())
  40           BB.setName("bb");
  41
  42         for (Instruction &I : BB)
  43           if (!I.hasName() && !I.getType()->isVoidTy())
  44             I.setName("tmp");
  45       }
  46       return true;
  47     }
  48   };
  49
  50   char InstNamer::ID = 0;
  51 }
  52
  53 INITIALIZE_PASS(InstNamer, "instnamer",
  54                 "Assign names to anonymous instructions", false, false)
  55 char &llvm::InstructionNamerID = InstNamer::ID;
  56 //===----------------------------------------------------------------------===//
  57 //
  58 // InstructionNamer - Give any unnamed non-void instructions "tmp" names.
  59 //
  60 FunctionPass *llvm::createInstructionNamerPass() {
  61   return new InstNamer();
  62 }