forked from suyu/suyu
42 lines
1.2 KiB
C++
42 lines
1.2 KiB
C++
// Copyright 2021 yuzu Emulator Project
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// Licensed under GPLv2 or any later version
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// Refer to the license.txt file included.
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#include <random>
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#include "core/hle/kernel/k_system_control.h"
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namespace Kernel {
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namespace {
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template <typename F>
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u64 GenerateUniformRange(u64 min, u64 max, F f) {
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// Handle the case where the difference is too large to represent.
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if (max == std::numeric_limits<u64>::max() && min == std::numeric_limits<u64>::min()) {
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return f();
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}
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// Iterate until we get a value in range.
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const u64 range_size = ((max + 1) - min);
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const u64 effective_max = (std::numeric_limits<u64>::max() / range_size) * range_size;
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while (true) {
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if (const u64 rnd = f(); rnd < effective_max) {
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return min + (rnd % range_size);
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}
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}
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}
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} // Anonymous namespace
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u64 KSystemControl::GenerateRandomU64() {
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static std::random_device device;
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static std::mt19937 gen(device());
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static std::uniform_int_distribution<u64> distribution(1, std::numeric_limits<u64>::max());
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return distribution(gen);
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}
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u64 KSystemControl::GenerateRandomRange(u64 min, u64 max) {
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return GenerateUniformRange(min, max, GenerateRandomU64);
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}
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} // namespace Kernel
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