1 //===- FuzzerValueBitMap.h - INTERNAL - Bit map -----------------*- C++ -* ===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 //===----------------------------------------------------------------------===//
12 #ifndef LLVM_FUZZER_VALUE_BIT_MAP_H
13 #define LLVM_FUZZER_VALUE_BIT_MAP_H
15 #include "FuzzerDefs.h"
19 // A bit map containing kMapSizeInWords bits.
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;
28 void Reset() { memset(Map, 0, sizeof(Map)); }
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_ALL
33 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 | (1UL << BitIdx);
43 ATTRIBUTE_NO_SANITIZE_ALL
44 inline bool AddValueModPrime(uintptr_t Value) {
45 return AddValue(Value % kMapPrimeMod);
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] & (1UL << BitIdx);
55 size_t GetNumBitsSinceLastMerge() const { return NumBits; }
57 // Merges 'Other' into 'this', clears 'Other', updates NumBits,
58 // returns true if new bits were added.
59 ATTRIBUTE_TARGET_POPCNT
60 bool MergeFrom(ValueBitMap &Other) {
62 size_t OldNumBits = NumBits;
63 for (size_t i = 0; i < kMapSizeInWords; i++) {
64 auto O = Other.Map[i];
71 Res += __builtin_popcountll(M);
74 return OldNumBits < NumBits;
77 template <class Callback>
78 ATTRIBUTE_NO_SANITIZE_ALL
79 void ForEach(Callback CB) const {
80 for (size_t i = 0; i < kMapSizeInWords; i++)
81 if (uintptr_t M = Map[i])
82 for (size_t j = 0; j < sizeof(M) * 8; j++)
83 if (M & ((uintptr_t)1 << j))
84 CB(i * sizeof(M) * 8 + j);
89 uintptr_t Map[kMapSizeInWords] __attribute__((aligned(512)));
94 #endif // LLVM_FUZZER_VALUE_BIT_MAP_H