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Diffstat (limited to 'ports/nrf/modules/random/modrandom.c')
| -rw-r--r-- | ports/nrf/modules/random/modrandom.c | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/ports/nrf/modules/random/modrandom.c b/ports/nrf/modules/random/modrandom.c new file mode 100644 index 000000000..0e140750d --- /dev/null +++ b/ports/nrf/modules/random/modrandom.c @@ -0,0 +1,177 @@ +/* + * This file is part of the MicroPython project, http://micropython.org/ + * + * The MIT License (MIT) + * + * Copyright (c) 2016 Paul Sokolovsky + * Copyright (c) 2016 Damien P. George + * + * 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/runtime.h" +#include "hal_rng.h" + +#if MICROPY_PY_HW_RNG + +static inline int rand30() { + uint32_t val = hal_rng_generate(); + return (val & 0x3fffffff); // binary mask b00111111111111111111111111111111 +} + +static inline int randbelow(int n) { + return rand30() % n; +} + +STATIC mp_obj_t mod_random_getrandbits(mp_obj_t num_in) { + int n = mp_obj_get_int(num_in); + if (n > 30 || n == 0) { + nlr_raise(mp_obj_new_exception(&mp_type_ValueError)); + } + 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(rand30() & mask); +} +STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_random_getrandbits_obj, mod_random_getrandbits); + +STATIC mp_obj_t mod_random_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(randbelow(start)); + } else { + nlr_raise(mp_obj_new_exception(&mp_type_ValueError)); + } + } 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 + randbelow(stop - start)); + } else { + nlr_raise(mp_obj_new_exception(&mp_type_ValueError)); + } + } 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 { + nlr_raise(mp_obj_new_exception(&mp_type_ValueError)); + } + if (n > 0) { + return mp_obj_new_int(start + step * randbelow(n)); + } else { + nlr_raise(mp_obj_new_exception(&mp_type_ValueError)); + } + } + } +} +STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mod_random_randrange_obj, 1, 3, mod_random_randrange); + +STATIC mp_obj_t mod_random_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 + randbelow(b - a + 1)); + } else { + nlr_raise(mp_obj_new_exception(&mp_type_ValueError)); + } +} +STATIC MP_DEFINE_CONST_FUN_OBJ_2(mod_random_randint_obj, mod_random_randint); + +STATIC mp_obj_t mod_random_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(randbelow(len)), MP_OBJ_SENTINEL); + } else { + nlr_raise(mp_obj_new_exception(&mp_type_IndexError)); + } +} +STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_random_choice_obj, mod_random_choice); + +#if MICROPY_PY_BUILTINS_FLOAT + +// returns a number in the range [0..1) using RNG to fill in the fraction bits +STATIC mp_float_t randfloat(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 <= 30) { + u.p.frc = rand30(); + } else { + u.p.frc = ((uint64_t)rand30() << 30) | (uint64_t)rand30(); + } + return u.f - 1; +} + +STATIC mp_obj_t mod_random_random(void) { + return mp_obj_new_float(randfloat()); +} +STATIC MP_DEFINE_CONST_FUN_OBJ_0(mod_random_random_obj, mod_random_random); + +STATIC mp_obj_t mod_random_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) * randfloat()); +} +STATIC MP_DEFINE_CONST_FUN_OBJ_2(mod_random_uniform_obj, mod_random_uniform); + +#endif + +STATIC const mp_rom_map_elem_t mp_module_random_globals_table[] = { + { MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_random) }, + { MP_ROM_QSTR(MP_QSTR_getrandbits), MP_ROM_PTR(&mod_random_getrandbits_obj) }, + { MP_ROM_QSTR(MP_QSTR_randrange), MP_ROM_PTR(&mod_random_randrange_obj) }, + { MP_ROM_QSTR(MP_QSTR_randint), MP_ROM_PTR(&mod_random_randint_obj) }, + { MP_ROM_QSTR(MP_QSTR_choice), MP_ROM_PTR(&mod_random_choice_obj) }, +#if MICROPY_PY_BUILTINS_FLOAT + { MP_ROM_QSTR(MP_QSTR_random), MP_ROM_PTR(&mod_random_random_obj) }, + { MP_ROM_QSTR(MP_QSTR_uniform), MP_ROM_PTR(&mod_random_uniform_obj) }, +#endif +}; + +STATIC MP_DEFINE_CONST_DICT(mp_module_random_globals, mp_module_random_globals_table); + +const mp_obj_module_t random_module = { + .base = { &mp_type_module }, + .globals = (mp_obj_dict_t*)&mp_module_random_globals, +}; + +#endif // MICROPY_PY_HW_RNG |