diff options
Diffstat (limited to 'extmod')
| -rw-r--r-- | extmod/modurandom.c | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/extmod/modurandom.c b/extmod/modurandom.c index 3ed6e9130e..27d7177207 100644 --- a/extmod/modurandom.c +++ b/extmod/modurandom.c @@ -53,6 +53,24 @@ STATIC uint32_t yasmarang(void) // 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) { @@ -75,10 +93,122 @@ STATIC mp_obj_t mod_urandom_seed(mp_obj_t seed_in) { } 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 { + 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 + yasmarang_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 * yasmarang_randbelow(n)); + } else { + nlr_raise(mp_obj_new_exception(&mp_type_ValueError)); + } + } + } +} +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 { + nlr_raise(mp_obj_new_exception(&mp_type_ValueError)); + } +} +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) }, + { 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 }; STATIC MP_DEFINE_CONST_DICT(mp_module_urandom_globals, mp_module_urandom_globals_table); |