1//===- ReduceSpecialGlobals.cpp - Specialized Delta Pass ------------------===//
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 file implements a function which calls the Generic Delta pass in order
10// to reduce special globals, like @llvm.used, in the provided Module.
11//
12// For more details about special globals, see
13// https://llvm.org/docs/LangRef.html#intrinsic-global-variables
14//
15//===----------------------------------------------------------------------===//
16
17#include "ReduceSpecialGlobals.h"
18#include "Delta.h"
19#include "Utils.h"
20#include "llvm/ADT/StringRef.h"
21#include "llvm/IR/Constants.h"
22#include "llvm/IR/GlobalValue.h"
23
24using namespace llvm;
25
26static StringRef SpecialGlobalNames[] = {"llvm.used", "llvm.compiler.used"};
27
28/// Removes all special globals aren't inside any of the
29/// desired Chunks.
30static void extractSpecialGlobalsFromModule(Oracle &O,
31 ReducerWorkItem &WorkItem) {
32 Module &Program = WorkItem.getModule();
33
34 for (StringRef Name : SpecialGlobalNames) {
35 if (auto *Used = Program.getNamedGlobal(Name)) {
36 Used->replaceAllUsesWith(V: getDefaultValue(T: Used->getType()));
37 Used->eraseFromParent();
38 }
39 }
40}
41
42void llvm::reduceSpecialGlobalsDeltaPass(TestRunner &Test) {
43 runDeltaPass(Test, ExtractChunksFromModule: extractSpecialGlobalsFromModule,
44 Message: "Reducing Special Globals");
45}
46