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//===- 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()(); }
template <typename T>
typename std::enable_if<std::is_integral<T>::value, T>::type Rand() {
return static_cast<T>(this->operator()());
}
size_t RandBool() { return this->operator()() % 2; }
size_t SkewTowardsLast(size_t n) {
size_t T = this->operator()(n * n);
size_t Res = static_cast<size_t>(sqrt(T));
return Res;
}
template <typename T>
typename std::enable_if<std::is_integral<T>::value, T>::type operator()(T n) {
return n ? Rand<T>() % n : 0;
}
template <typename T>
typename std::enable_if<std::is_integral<T>::value, T>::type
operator()(T From, T To) {
assert(From < To);
auto RangeSize = static_cast<unsigned long long>(To) -
static_cast<unsigned long long>(From) + 1;
return static_cast<T>(this->operator()(RangeSize) + From);
}
};
} // namespace fuzzer
#endif // LLVM_FUZZER_RANDOM_H