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1//===- FuzzerValueBitMap.h - INTERNAL - Bit map -----------------*- C++ -* ===//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-exception6//7//===----------------------------------------------------------------------===//8// ValueBitMap.9//===----------------------------------------------------------------------===//10 11#ifndef LLVM_FUZZER_VALUE_BIT_MAP_H12#define LLVM_FUZZER_VALUE_BIT_MAP_H13 14#include "FuzzerPlatform.h"15#include <cstdint>16 17namespace fuzzer {18 19// A bit map containing kMapSizeInWords bits.20struct ValueBitMap {21 static const size_t kMapSizeInBits = 1 << 16;22 static const size_t kMapPrimeMod = 65371; // Largest Prime < kMapSizeInBits;23 static const size_t kBitsInWord = (sizeof(uintptr_t) * 8);24 static const size_t kMapSizeInWords = kMapSizeInBits / kBitsInWord;25 public:26 27 // Clears all bits.28 void Reset() { memset(Map, 0, sizeof(Map)); }29 30 // Computes a hash function of Value and sets the corresponding bit.31 // Returns true if the bit was changed from 0 to 1.32 ATTRIBUTE_NO_SANITIZE_ALL33 inline bool AddValue(uintptr_t Value) {34 uintptr_t Idx = Value % kMapSizeInBits;35 uintptr_t WordIdx = Idx / kBitsInWord;36 uintptr_t BitIdx = Idx % kBitsInWord;37 uintptr_t Old = Map[WordIdx];38 uintptr_t New = Old | (1ULL << BitIdx);39 Map[WordIdx] = New;40 return New != Old;41 }42 43 ATTRIBUTE_NO_SANITIZE_ALL44 inline bool AddValueModPrime(uintptr_t Value) {45 return AddValue(Value % kMapPrimeMod);46 }47 48 inline bool Get(uintptr_t Idx) {49 assert(Idx < kMapSizeInBits);50 uintptr_t WordIdx = Idx / kBitsInWord;51 uintptr_t BitIdx = Idx % kBitsInWord;52 return Map[WordIdx] & (1ULL << BitIdx);53 }54 55 size_t SizeInBits() const { return kMapSizeInBits; }56 57 template <class Callback>58 ATTRIBUTE_NO_SANITIZE_ALL59 void ForEach(Callback CB) const {60 for (size_t i = 0; i < kMapSizeInWords; i++)61 if (uintptr_t M = Map[i])62 for (size_t j = 0; j < sizeof(M) * 8; j++)63 if (M & ((uintptr_t)1 << j))64 CB(i * sizeof(M) * 8 + j);65 }66 67 private:68 ATTRIBUTE_ALIGNED(512) uintptr_t Map[kMapSizeInWords];69};70 71} // namespace fuzzer72 73#endif // LLVM_FUZZER_VALUE_BIT_MAP_H74