blob: bc191e49faeaf1f51060aa10280266bbfe722618 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
|
//===- FuzzerValueBitMap.h - INTERNAL - Bit map -----------------*- C++ -* ===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// ValueBitMap.
//===----------------------------------------------------------------------===//
#ifndef LLVM_FUZZER_VALUE_BIT_MAP_H
#define LLVM_FUZZER_VALUE_BIT_MAP_H
#include "FuzzerDefs.h"
namespace fuzzer {
// A bit map containing kMapSizeInWords bits.
struct ValueBitMap {
static const size_t kMapSizeInBits = 65371; // Prime.
static const size_t kMapSizeInBitsAligned = 65536; // 2^16
static const size_t kBitsInWord = (sizeof(uintptr_t) * 8);
static const size_t kMapSizeInWords = kMapSizeInBitsAligned / kBitsInWord;
public:
static const size_t kNumberOfItems = kMapSizeInBits;
// Clears all bits.
void Reset() { memset(Map, 0, sizeof(Map)); }
// Computes a hash function of Value and sets the corresponding bit.
// Returns true if the bit was changed from 0 to 1.
inline bool AddValue(uintptr_t Value) {
uintptr_t Idx = Value < kMapSizeInBits ? Value : Value % kMapSizeInBits;
uintptr_t WordIdx = Idx / kBitsInWord;
uintptr_t BitIdx = Idx % kBitsInWord;
uintptr_t Old = Map[WordIdx];
uintptr_t New = Old | (1UL << BitIdx);
Map[WordIdx] = New;
return New != Old;
}
inline bool Get(uintptr_t Idx) {
assert(Idx < kMapSizeInBits);
uintptr_t WordIdx = Idx / kBitsInWord;
uintptr_t BitIdx = Idx % kBitsInWord;
return Map[WordIdx] & (1UL << BitIdx);
}
size_t GetNumBitsSinceLastMerge() const { return NumBits; }
// Merges 'Other' into 'this', clears 'Other', updates NumBits,
// returns true if new bits were added.
ATTRIBUTE_TARGET_POPCNT
bool MergeFrom(ValueBitMap &Other) {
uintptr_t Res = 0;
size_t OldNumBits = NumBits;
for (size_t i = 0; i < kMapSizeInWords; i++) {
auto O = Other.Map[i];
auto M = Map[i];
if (O) {
Map[i] = (M |= O);
Other.Map[i] = 0;
}
if (M)
Res += __builtin_popcountl(M);
}
NumBits = Res;
return OldNumBits < NumBits;
}
private:
size_t NumBits;
uintptr_t Map[kMapSizeInWords] __attribute__((aligned(512)));
};
} // namespace fuzzer
#endif // LLVM_FUZZER_VALUE_BIT_MAP_H
|
