xref: /openbsd-src/gnu/llvm/compiler-rt/lib/fuzzer/FuzzerValueBitMap.h (revision 1f9cb04fc6f537ca6cf5a53c28927340cba218a2)
13cab2bb3Spatrick //===- FuzzerValueBitMap.h - INTERNAL - Bit map -----------------*- C++ -* ===//
23cab2bb3Spatrick //
33cab2bb3Spatrick // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
43cab2bb3Spatrick // See https://llvm.org/LICENSE.txt for license information.
53cab2bb3Spatrick // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
63cab2bb3Spatrick //
73cab2bb3Spatrick //===----------------------------------------------------------------------===//
83cab2bb3Spatrick // ValueBitMap.
93cab2bb3Spatrick //===----------------------------------------------------------------------===//
103cab2bb3Spatrick 
113cab2bb3Spatrick #ifndef LLVM_FUZZER_VALUE_BIT_MAP_H
123cab2bb3Spatrick #define LLVM_FUZZER_VALUE_BIT_MAP_H
133cab2bb3Spatrick 
14*1f9cb04fSpatrick #include "FuzzerPlatform.h"
15*1f9cb04fSpatrick #include <cstdint>
163cab2bb3Spatrick 
173cab2bb3Spatrick namespace fuzzer {
183cab2bb3Spatrick 
193cab2bb3Spatrick // A bit map containing kMapSizeInWords bits.
203cab2bb3Spatrick struct ValueBitMap {
213cab2bb3Spatrick   static const size_t kMapSizeInBits = 1 << 16;
223cab2bb3Spatrick   static const size_t kMapPrimeMod = 65371;  // Largest Prime < kMapSizeInBits;
233cab2bb3Spatrick   static const size_t kBitsInWord = (sizeof(uintptr_t) * 8);
243cab2bb3Spatrick   static const size_t kMapSizeInWords = kMapSizeInBits / kBitsInWord;
253cab2bb3Spatrick  public:
263cab2bb3Spatrick 
273cab2bb3Spatrick   // Clears all bits.
ResetValueBitMap283cab2bb3Spatrick   void Reset() { memset(Map, 0, sizeof(Map)); }
293cab2bb3Spatrick 
303cab2bb3Spatrick   // Computes a hash function of Value and sets the corresponding bit.
313cab2bb3Spatrick   // Returns true if the bit was changed from 0 to 1.
323cab2bb3Spatrick   ATTRIBUTE_NO_SANITIZE_ALL
AddValueValueBitMap333cab2bb3Spatrick   inline bool AddValue(uintptr_t Value) {
343cab2bb3Spatrick     uintptr_t Idx = Value % kMapSizeInBits;
353cab2bb3Spatrick     uintptr_t WordIdx = Idx / kBitsInWord;
363cab2bb3Spatrick     uintptr_t BitIdx = Idx % kBitsInWord;
373cab2bb3Spatrick     uintptr_t Old = Map[WordIdx];
383cab2bb3Spatrick     uintptr_t New = Old | (1ULL << BitIdx);
393cab2bb3Spatrick     Map[WordIdx] = New;
403cab2bb3Spatrick     return New != Old;
413cab2bb3Spatrick   }
423cab2bb3Spatrick 
433cab2bb3Spatrick   ATTRIBUTE_NO_SANITIZE_ALL
AddValueModPrimeValueBitMap443cab2bb3Spatrick   inline bool AddValueModPrime(uintptr_t Value) {
453cab2bb3Spatrick     return AddValue(Value % kMapPrimeMod);
463cab2bb3Spatrick   }
473cab2bb3Spatrick 
GetValueBitMap483cab2bb3Spatrick   inline bool Get(uintptr_t Idx) {
493cab2bb3Spatrick     assert(Idx < kMapSizeInBits);
503cab2bb3Spatrick     uintptr_t WordIdx = Idx / kBitsInWord;
513cab2bb3Spatrick     uintptr_t BitIdx = Idx % kBitsInWord;
523cab2bb3Spatrick     return Map[WordIdx] & (1ULL << BitIdx);
533cab2bb3Spatrick   }
543cab2bb3Spatrick 
SizeInBitsValueBitMap553cab2bb3Spatrick   size_t SizeInBits() const { return kMapSizeInBits; }
563cab2bb3Spatrick 
573cab2bb3Spatrick   template <class Callback>
583cab2bb3Spatrick   ATTRIBUTE_NO_SANITIZE_ALL
ForEachValueBitMap593cab2bb3Spatrick   void ForEach(Callback CB) const {
603cab2bb3Spatrick     for (size_t i = 0; i < kMapSizeInWords; i++)
613cab2bb3Spatrick       if (uintptr_t M = Map[i])
623cab2bb3Spatrick         for (size_t j = 0; j < sizeof(M) * 8; j++)
633cab2bb3Spatrick           if (M & ((uintptr_t)1 << j))
643cab2bb3Spatrick             CB(i * sizeof(M) * 8 + j);
653cab2bb3Spatrick   }
663cab2bb3Spatrick 
673cab2bb3Spatrick  private:
683cab2bb3Spatrick   ATTRIBUTE_ALIGNED(512) uintptr_t Map[kMapSizeInWords];
693cab2bb3Spatrick };
703cab2bb3Spatrick 
713cab2bb3Spatrick }  // namespace fuzzer
723cab2bb3Spatrick 
733cab2bb3Spatrick #endif  // LLVM_FUZZER_VALUE_BIT_MAP_H
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