1 //===- FuzzerValueBitMap.h - INTERNAL - Bit map -----------------*- C++ -* ===//
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
7 //===----------------------------------------------------------------------===//
9 //===----------------------------------------------------------------------===//
11 #ifndef LLVM_FUZZER_VALUE_BIT_MAP_H
12 #define LLVM_FUZZER_VALUE_BIT_MAP_H
14 #include "FuzzerDefs.h"
18 // A bit map containing kMapSizeInWords bits.
20 static const size_t kMapSizeInBits = 1 << 16;
21 static const size_t kMapPrimeMod = 65371; // Largest Prime < kMapSizeInBits;
22 static const size_t kBitsInWord = (sizeof(uintptr_t) * 8);
23 static const size_t kMapSizeInWords = kMapSizeInBits / kBitsInWord;
27 void Reset() { memset(Map, 0, sizeof(Map)); }
29 // Computes a hash function of Value and sets the corresponding bit.
30 // Returns true if the bit was changed from 0 to 1.
31 ATTRIBUTE_NO_SANITIZE_ALL
32 inline bool AddValue(uintptr_t Value) {
33 uintptr_t Idx = Value % kMapSizeInBits;
34 uintptr_t WordIdx = Idx / kBitsInWord;
35 uintptr_t BitIdx = Idx % kBitsInWord;
36 uintptr_t Old = Map[WordIdx];
37 uintptr_t New = Old | (1ULL << BitIdx);
42 ATTRIBUTE_NO_SANITIZE_ALL
43 inline bool AddValueModPrime(uintptr_t Value) {
44 return AddValue(Value % kMapPrimeMod);
47 inline bool Get(uintptr_t Idx) {
48 assert(Idx < kMapSizeInBits);
49 uintptr_t WordIdx = Idx / kBitsInWord;
50 uintptr_t BitIdx = Idx % kBitsInWord;
51 return Map[WordIdx] & (1ULL << BitIdx);
54 size_t SizeInBits() const { return kMapSizeInBits; }
56 template <class Callback>
57 ATTRIBUTE_NO_SANITIZE_ALL
58 void ForEach(Callback CB) const {
59 for (size_t i = 0; i < kMapSizeInWords; i++)
60 if (uintptr_t M = Map[i])
61 for (size_t j = 0; j < sizeof(M) * 8; j++)
62 if (M & ((uintptr_t)1 << j))
63 CB(i * sizeof(M) * 8 + j);
67 ATTRIBUTE_ALIGNED(512) uintptr_t Map[kMapSizeInWords];
72 #endif // LLVM_FUZZER_VALUE_BIT_MAP_H