llvm-project/compiler-rt/lib/fuzzer/FuzzerRandom.h

39 lines
1.2 KiB
C++

//===- FuzzerRandom.h - Internal header for the Fuzzer ----------*- C++ -* ===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// fuzzer::Random
//===----------------------------------------------------------------------===//
#ifndef LLVM_FUZZER_RANDOM_H
#define LLVM_FUZZER_RANDOM_H
#include <random>
namespace fuzzer {
class Random : public std::minstd_rand {
public:
Random(unsigned int seed) : std::minstd_rand(seed) {}
result_type operator()() { return this->std::minstd_rand::operator()(); }
size_t Rand() { return this->operator()(); }
size_t RandBool() { return Rand() % 2; }
size_t SkewTowardsLast(size_t n) {
size_t T = this->operator()(n * n);
size_t Res = sqrt(T);
return Res;
}
size_t operator()(size_t n) { return n ? Rand() % n : 0; }
intptr_t operator()(intptr_t From, intptr_t To) {
assert(From < To);
intptr_t RangeSize = To - From + 1;
return operator()(RangeSize) + From;
}
};
} // namespace fuzzer
#endif // LLVM_FUZZER_RANDOM_H