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 24 using namespace llvm; 25 26 static StringRef SpecialGlobalNames[] = {"llvm.used", "llvm.compiler.used"}; 27 28 /// Removes all special globals aren't inside any of the 29 /// desired Chunks. extractSpecialGlobalsFromModule(Oracle & O,ReducerWorkItem & WorkItem)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(getDefaultValue(Used->getType())); 37 Used->eraseFromParent(); 38 } 39 } 40 } 41 reduceSpecialGlobalsDeltaPass(TestRunner & Test)42void llvm::reduceSpecialGlobalsDeltaPass(TestRunner &Test) { 43 runDeltaPass(Test, extractSpecialGlobalsFromModule, 44 "Reducing Special Globals"); 45 } 46