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/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2016 Paul Sokolovsky
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include <assert.h>
#include <string.h>
//#include "py/nlr.h"
#include "py/runtime.h"
#if MICROPY_PY_URANDOM
// Yasmarang random number generator
// by Ilya Levin
// http://www.literatecode.com/yasmarang
// Public Domain
STATIC uint32_t yasmarang_pad = 0xeda4baba, yasmarang_n = 69, yasmarang_d = 233;
STATIC uint8_t yasmarang_dat = 0;
STATIC uint32_t yasmarang(void)
{
yasmarang_pad += yasmarang_dat + yasmarang_d * yasmarang_n;
yasmarang_pad = (yasmarang_pad<<3) + (yasmarang_pad>>29);
yasmarang_n = yasmarang_pad | 2;
yasmarang_d ^= (yasmarang_pad<<31) + (yasmarang_pad>>1);
yasmarang_dat ^= (char) yasmarang_pad ^ (yasmarang_d>>8) ^ 1;
return (yasmarang_pad^(yasmarang_d<<5)^(yasmarang_pad>>18)^(yasmarang_dat<<1));
} /* yasmarang */
// End of Yasmarang
#if MICROPY_PY_URANDOM_EXTRA_FUNCS
// returns an unsigned integer below the given argument
// n must not be zero
STATIC uint32_t yasmarang_randbelow(uint32_t n) {
uint32_t mask = 1;
while ((n & mask) < n) {
mask = (mask << 1) | 1;
}
uint32_t r;
do {
r = yasmarang() & mask;
} while (r >= n);
return r;
}
#endif
STATIC mp_obj_t mod_urandom_getrandbits(mp_obj_t num_in) {
int n = mp_obj_get_int(num_in);
if (n > 32 || n == 0) {
mp_raise_ValueError(NULL);
}
uint32_t mask = ~0;
// Beware of C undefined behavior when shifting by >= than bit size
mask >>= (32 - n);
return mp_obj_new_int_from_uint(yasmarang() & mask);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_urandom_getrandbits_obj, mod_urandom_getrandbits);
STATIC mp_obj_t mod_urandom_seed(mp_obj_t seed_in) {
mp_uint_t seed = mp_obj_get_int_truncated(seed_in);
yasmarang_pad = seed;
yasmarang_n = 69;
yasmarang_d = 233;
yasmarang_dat = 0;
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_urandom_seed_obj, mod_urandom_seed);
#if MICROPY_PY_URANDOM_EXTRA_FUNCS
STATIC mp_obj_t mod_urandom_randrange(size_t n_args, const mp_obj_t *args) {
mp_int_t start = mp_obj_get_int(args[0]);
if (n_args == 1) {
// range(stop)
if (start > 0) {
return mp_obj_new_int(yasmarang_randbelow(start));
} else {
goto error;
}
} else {
mp_int_t stop = mp_obj_get_int(args[1]);
if (n_args == 2) {
// range(start, stop)
if (start < stop) {
return mp_obj_new_int(start + yasmarang_randbelow(stop - start));
} else {
goto error;
}
} else {
// range(start, stop, step)
mp_int_t step = mp_obj_get_int(args[2]);
mp_int_t n;
if (step > 0) {
n = (stop - start + step - 1) / step;
} else if (step < 0) {
n = (stop - start + step + 1) / step;
} else {
goto error;
}
if (n > 0) {
return mp_obj_new_int(start + step * yasmarang_randbelow(n));
} else {
goto error;
}
}
}
error:
mp_raise_ValueError(NULL);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mod_urandom_randrange_obj, 1, 3, mod_urandom_randrange);
STATIC mp_obj_t mod_urandom_randint(mp_obj_t a_in, mp_obj_t b_in) {
mp_int_t a = mp_obj_get_int(a_in);
mp_int_t b = mp_obj_get_int(b_in);
if (a <= b) {
return mp_obj_new_int(a + yasmarang_randbelow(b - a + 1));
} else {
mp_raise_ValueError(NULL);
}
}
STATIC MP_DEFINE_CONST_FUN_OBJ_2(mod_urandom_randint_obj, mod_urandom_randint);
STATIC mp_obj_t mod_urandom_choice(mp_obj_t seq) {
mp_int_t len = mp_obj_get_int(mp_obj_len(seq));
if (len > 0) {
return mp_obj_subscr(seq, mp_obj_new_int(yasmarang_randbelow(len)), MP_OBJ_SENTINEL);
} else {
nlr_raise(mp_obj_new_exception(&mp_type_IndexError));
}
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_urandom_choice_obj, mod_urandom_choice);
#if MICROPY_PY_BUILTINS_FLOAT
// returns a number in the range [0..1) using Yasmarang to fill in the fraction bits
STATIC mp_float_t yasmarang_float(void) {
#if MICROPY_FLOAT_IMPL == MICROPY_FLOAT_IMPL_DOUBLE
typedef uint64_t mp_float_int_t;
#elif MICROPY_FLOAT_IMPL == MICROPY_FLOAT_IMPL_FLOAT
typedef uint32_t mp_float_int_t;
#endif
union {
mp_float_t f;
#if MP_ENDIANNESS_LITTLE
struct { mp_float_int_t frc:MP_FLOAT_FRAC_BITS, exp:MP_FLOAT_EXP_BITS, sgn:1; } p;
#else
struct { mp_float_int_t sgn:1, exp:MP_FLOAT_EXP_BITS, frc:MP_FLOAT_FRAC_BITS; } p;
#endif
} u;
u.p.sgn = 0;
u.p.exp = (1 << (MP_FLOAT_EXP_BITS - 1)) - 1;
if (MP_FLOAT_FRAC_BITS <= 32) {
u.p.frc = yasmarang();
} else {
u.p.frc = ((uint64_t)yasmarang() << 32) | (uint64_t)yasmarang();
}
return u.f - 1;
}
STATIC mp_obj_t mod_urandom_random(void) {
return mp_obj_new_float(yasmarang_float());
}
STATIC MP_DEFINE_CONST_FUN_OBJ_0(mod_urandom_random_obj, mod_urandom_random);
STATIC mp_obj_t mod_urandom_uniform(mp_obj_t a_in, mp_obj_t b_in) {
mp_float_t a = mp_obj_get_float(a_in);
mp_float_t b = mp_obj_get_float(b_in);
return mp_obj_new_float(a + (b - a) * yasmarang_float());
}
STATIC MP_DEFINE_CONST_FUN_OBJ_2(mod_urandom_uniform_obj, mod_urandom_uniform);
#endif
#endif // MICROPY_PY_URANDOM_EXTRA_FUNCS
STATIC const mp_rom_map_elem_t mp_module_urandom_globals_table[] = {
{ MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_urandom) },
{ MP_ROM_QSTR(MP_QSTR_getrandbits), MP_ROM_PTR(&mod_urandom_getrandbits_obj) },
{ MP_ROM_QSTR(MP_QSTR_seed), MP_ROM_PTR(&mod_urandom_seed_obj) },
#if MICROPY_PY_URANDOM_EXTRA_FUNCS
{ MP_ROM_QSTR(MP_QSTR_randrange), MP_ROM_PTR(&mod_urandom_randrange_obj) },
{ MP_ROM_QSTR(MP_QSTR_randint), MP_ROM_PTR(&mod_urandom_randint_obj) },
{ MP_ROM_QSTR(MP_QSTR_choice), MP_ROM_PTR(&mod_urandom_choice_obj) },
#if MICROPY_PY_BUILTINS_FLOAT
{ MP_ROM_QSTR(MP_QSTR_random), MP_ROM_PTR(&mod_urandom_random_obj) },
{ MP_ROM_QSTR(MP_QSTR_uniform), MP_ROM_PTR(&mod_urandom_uniform_obj) },
#endif
#endif
};
STATIC MP_DEFINE_CONST_DICT(mp_module_urandom_globals, mp_module_urandom_globals_table);
const mp_obj_module_t mp_module_urandom = {
.base = { &mp_type_module },
.globals = (mp_obj_dict_t*)&mp_module_urandom_globals,
};
#endif //MICROPY_PY_URANDOM