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// Copyright 2022 - 2023 Alejandro Colomar <alx@kernel.org>
// SPDX-License-Identifier: LGPL-3.0-or-later WITH LGPL-3.0-linking-exception
#ifndef INCLUDE_C_RAND_RAND_RAND_UNIFORM_H_
#define INCLUDE_C_RAND_RAND_RAND_UNIFORM_H_
#include <assert.h>
#include <stdint.h>
#include <c/bit/ceil.h>
#include <c/rand/rand/rand.h>
#pragma clang assume_nonnull begin
inline int c_rand_uniform(unsigned int n);
inline int c_rand_interval(unsigned int min, unsigned int max);
inline int
c_rand_uniform(unsigned int n)
{
unsigned int r, max, mask;
static_assert(sizeof(int) == sizeof(uint32_t));
max = n - 1;
mask = c_bit_ceil_wrap_32(n) - 1;
do {
r = c_rand();
r &= mask;
} while (r > max);
return r;
}
inline int
c_rand_interval(unsigned int min, unsigned int max)
{
return c_rand_uniform(max - min + 1) + min;
}
#pragma clang assume_nonnull end
#endif // Header guard
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