micropython/py/objfloat.c

332 lines
11 KiB
C

/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2013, 2014 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 <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <assert.h>
#include "py/parsenum.h"
#include "py/runtime.h"
#if MICROPY_PY_BUILTINS_FLOAT
#include <math.h>
#include "py/formatfloat.h"
#if MICROPY_OBJ_REPR != MICROPY_OBJ_REPR_C && MICROPY_OBJ_REPR != MICROPY_OBJ_REPR_D
// M_E and M_PI are not part of the math.h standard and may not be defined
#ifndef M_E
#define M_E (2.7182818284590452354)
#endif
#ifndef M_PI
#define M_PI (3.14159265358979323846)
#endif
typedef struct _mp_obj_float_t {
mp_obj_base_t base;
mp_float_t value;
} mp_obj_float_t;
const mp_obj_float_t mp_const_float_e_obj = {{&mp_type_float}, M_E};
const mp_obj_float_t mp_const_float_pi_obj = {{&mp_type_float}, M_PI};
#endif
#if MICROPY_FLOAT_HIGH_QUALITY_HASH
// must return actual integer value if it fits in mp_int_t
mp_int_t mp_float_hash(mp_float_t src) {
mp_float_union_t u = {.f = src};
mp_int_t val;
const int adj_exp = (int)u.p.exp - MP_FLOAT_EXP_BIAS;
if (adj_exp < 0) {
// value < 1; must be sure to handle 0.0 correctly (ie return 0)
val = u.i;
} else {
// if adj_exp is max then: u.p.frc==0 indicates inf, else NaN
// else: 1 <= value
mp_float_uint_t frc = u.p.frc | ((mp_float_uint_t)1 << MP_FLOAT_FRAC_BITS);
if (adj_exp <= MP_FLOAT_FRAC_BITS) {
// number may have a fraction; xor the integer part with the fractional part
val = (frc >> (MP_FLOAT_FRAC_BITS - adj_exp))
^ (frc & (((mp_float_uint_t)1 << (MP_FLOAT_FRAC_BITS - adj_exp)) - 1));
} else if ((unsigned int)adj_exp < BITS_PER_BYTE * sizeof(mp_int_t) - 1) {
// the number is a (big) whole integer and will fit in val's signed-width
val = (mp_int_t)frc << (adj_exp - MP_FLOAT_FRAC_BITS);
} else {
// integer part will overflow val's width so just use what bits we can
val = frc;
}
}
if (u.p.sgn) {
val = -(mp_uint_t)val;
}
return val;
}
#endif
STATIC void float_print(const mp_print_t *print, mp_obj_t o_in, mp_print_kind_t kind) {
(void)kind;
mp_float_t o_val = mp_obj_float_get(o_in);
#if MICROPY_FLOAT_IMPL == MICROPY_FLOAT_IMPL_FLOAT
char buf[16];
#if MICROPY_OBJ_REPR == MICROPY_OBJ_REPR_C
const int precision = 6;
#else
const int precision = 7;
#endif
#else
char buf[32];
const int precision = 16;
#endif
mp_format_float(o_val, buf, sizeof(buf), 'g', precision, '\0');
mp_print_str(print, buf);
if (strchr(buf, '.') == NULL && strchr(buf, 'e') == NULL && strchr(buf, 'n') == NULL) {
// Python floats always have decimal point (unless inf or nan)
mp_print_str(print, ".0");
}
}
STATIC mp_obj_t float_make_new(const mp_obj_type_t *type_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
(void)type_in;
mp_arg_check_num(n_args, n_kw, 0, 1, false);
switch (n_args) {
case 0:
return mp_obj_new_float(0);
case 1:
default: {
mp_buffer_info_t bufinfo;
if (mp_get_buffer(args[0], &bufinfo, MP_BUFFER_READ)) {
// a textual representation, parse it
return mp_parse_num_decimal(bufinfo.buf, bufinfo.len, false, false, NULL);
} else if (mp_obj_is_float(args[0])) {
// a float, just return it
return args[0];
} else {
// something else, try to cast it to a float
return mp_obj_new_float(mp_obj_get_float(args[0]));
}
}
}
}
STATIC mp_obj_t float_unary_op(mp_unary_op_t op, mp_obj_t o_in) {
mp_float_t val = mp_obj_float_get(o_in);
switch (op) {
case MP_UNARY_OP_BOOL:
return mp_obj_new_bool(val != 0);
case MP_UNARY_OP_HASH:
return MP_OBJ_NEW_SMALL_INT(mp_float_hash(val));
case MP_UNARY_OP_POSITIVE:
return o_in;
case MP_UNARY_OP_NEGATIVE:
return mp_obj_new_float(-val);
case MP_UNARY_OP_ABS: {
if (signbit(val)) {
return mp_obj_new_float(-val);
} else {
return o_in;
}
}
default:
return MP_OBJ_NULL; // op not supported
}
}
STATIC mp_obj_t float_binary_op(mp_binary_op_t op, mp_obj_t lhs_in, mp_obj_t rhs_in) {
mp_float_t lhs_val = mp_obj_float_get(lhs_in);
#if MICROPY_PY_BUILTINS_COMPLEX
if (mp_obj_is_type(rhs_in, &mp_type_complex)) {
return mp_obj_complex_binary_op(op, lhs_val, 0, rhs_in);
}
#endif
return mp_obj_float_binary_op(op, lhs_val, rhs_in);
}
const mp_obj_type_t mp_type_float = {
{ &mp_type_type },
.flags = MP_TYPE_FLAG_EQ_NOT_REFLEXIVE | MP_TYPE_FLAG_EQ_CHECKS_OTHER_TYPE,
.name = MP_QSTR_float,
.print = float_print,
.make_new = float_make_new,
.unary_op = float_unary_op,
.binary_op = float_binary_op,
};
#if MICROPY_OBJ_REPR != MICROPY_OBJ_REPR_C && MICROPY_OBJ_REPR != MICROPY_OBJ_REPR_D
mp_obj_t mp_obj_new_float(mp_float_t value) {
mp_obj_float_t *o = m_new(mp_obj_float_t, 1);
o->base.type = &mp_type_float;
o->value = value;
return MP_OBJ_FROM_PTR(o);
}
mp_float_t mp_obj_float_get(mp_obj_t self_in) {
assert(mp_obj_is_float(self_in));
mp_obj_float_t *self = MP_OBJ_TO_PTR(self_in);
return self->value;
}
#endif
STATIC void mp_obj_float_divmod(mp_float_t *x, mp_float_t *y) {
// logic here follows that of CPython
// https://docs.python.org/3/reference/expressions.html#binary-arithmetic-operations
// x == (x//y)*y + (x%y)
// divmod(x, y) == (x//y, x%y)
mp_float_t mod = MICROPY_FLOAT_C_FUN(fmod)(*x, *y);
mp_float_t div = (*x - mod) / *y;
// Python specs require that mod has same sign as second operand
if (mod == 0.0) {
mod = MICROPY_FLOAT_C_FUN(copysign)(0.0, *y);
} else {
if ((mod < 0.0) != (*y < 0.0)) {
mod += *y;
div -= 1.0;
}
}
mp_float_t floordiv;
if (div == 0.0) {
// if division is zero, take the correct sign of zero
floordiv = MICROPY_FLOAT_C_FUN(copysign)(0.0, *x / *y);
} else {
// Python specs require that x == (x//y)*y + (x%y)
floordiv = MICROPY_FLOAT_C_FUN(floor)(div);
if (div - floordiv > 0.5) {
floordiv += 1.0;
}
}
// return results
*x = floordiv;
*y = mod;
}
mp_obj_t mp_obj_float_binary_op(mp_binary_op_t op, mp_float_t lhs_val, mp_obj_t rhs_in) {
mp_float_t rhs_val;
if (!mp_obj_get_float_maybe(rhs_in, &rhs_val)) {
return MP_OBJ_NULL; // op not supported
}
switch (op) {
case MP_BINARY_OP_ADD:
case MP_BINARY_OP_INPLACE_ADD:
lhs_val += rhs_val;
break;
case MP_BINARY_OP_SUBTRACT:
case MP_BINARY_OP_INPLACE_SUBTRACT:
lhs_val -= rhs_val;
break;
case MP_BINARY_OP_MULTIPLY:
case MP_BINARY_OP_INPLACE_MULTIPLY:
lhs_val *= rhs_val;
break;
case MP_BINARY_OP_FLOOR_DIVIDE:
case MP_BINARY_OP_INPLACE_FLOOR_DIVIDE:
if (rhs_val == 0) {
zero_division_error:
mp_raise_msg(&mp_type_ZeroDivisionError, MP_ERROR_TEXT("divide by zero"));
}
// Python specs require that x == (x//y)*y + (x%y) so we must
// call divmod to compute the correct floor division, which
// returns the floor divide in lhs_val.
mp_obj_float_divmod(&lhs_val, &rhs_val);
break;
case MP_BINARY_OP_TRUE_DIVIDE:
case MP_BINARY_OP_INPLACE_TRUE_DIVIDE:
if (rhs_val == 0) {
goto zero_division_error;
}
lhs_val /= rhs_val;
break;
case MP_BINARY_OP_MODULO:
case MP_BINARY_OP_INPLACE_MODULO:
if (rhs_val == 0) {
goto zero_division_error;
}
lhs_val = MICROPY_FLOAT_C_FUN(fmod)(lhs_val, rhs_val);
// Python specs require that mod has same sign as second operand
if (lhs_val == 0.0) {
lhs_val = MICROPY_FLOAT_C_FUN(copysign)(0.0, rhs_val);
} else {
if ((lhs_val < 0.0) != (rhs_val < 0.0)) {
lhs_val += rhs_val;
}
}
break;
case MP_BINARY_OP_POWER:
case MP_BINARY_OP_INPLACE_POWER:
if (lhs_val == 0 && rhs_val < 0 && !isinf(rhs_val)) {
goto zero_division_error;
}
if (lhs_val < 0 && rhs_val != MICROPY_FLOAT_C_FUN(floor)(rhs_val)) {
#if MICROPY_PY_BUILTINS_COMPLEX
return mp_obj_complex_binary_op(MP_BINARY_OP_POWER, lhs_val, 0, rhs_in);
#else
mp_raise_ValueError(MP_ERROR_TEXT("complex values not supported"));
#endif
}
lhs_val = MICROPY_FLOAT_C_FUN(pow)(lhs_val, rhs_val);
break;
case MP_BINARY_OP_DIVMOD: {
if (rhs_val == 0) {
goto zero_division_error;
}
mp_obj_float_divmod(&lhs_val, &rhs_val);
mp_obj_t tuple[2] = {
mp_obj_new_float(lhs_val),
mp_obj_new_float(rhs_val),
};
return mp_obj_new_tuple(2, tuple);
}
case MP_BINARY_OP_LESS:
return mp_obj_new_bool(lhs_val < rhs_val);
case MP_BINARY_OP_MORE:
return mp_obj_new_bool(lhs_val > rhs_val);
case MP_BINARY_OP_EQUAL:
return mp_obj_new_bool(lhs_val == rhs_val);
case MP_BINARY_OP_LESS_EQUAL:
return mp_obj_new_bool(lhs_val <= rhs_val);
case MP_BINARY_OP_MORE_EQUAL:
return mp_obj_new_bool(lhs_val >= rhs_val);
default:
return MP_OBJ_NULL; // op not supported
}
return mp_obj_new_float(lhs_val);
}
#endif // MICROPY_PY_BUILTINS_FLOAT