diff options
Diffstat (limited to 'Objects/floatobject.c')
-rw-r--r-- | Objects/floatobject.c | 352 |
1 files changed, 278 insertions, 74 deletions
diff --git a/Objects/floatobject.c b/Objects/floatobject.c index d92bec3..80bf71e 100644 --- a/Objects/floatobject.c +++ b/Objects/floatobject.c @@ -124,11 +124,43 @@ PyFloat_FromDouble(double fval) return (PyObject *) op; } +static PyObject * +float_from_string_inner(const char *s, Py_ssize_t len, void *obj) +{ + double x; + const char *end; + const char *last = s + len; + /* strip space */ + while (s < last && Py_ISSPACE(*s)) { + s++; + } + + while (s < last - 1 && Py_ISSPACE(last[-1])) { + last--; + } + + /* We don't care about overflow or underflow. If the platform + * supports them, infinities and signed zeroes (on underflow) are + * fine. */ + x = PyOS_string_to_double(s, (char **)&end, NULL); + if (end != last) { + PyErr_Format(PyExc_ValueError, + "could not convert string to float: " + "%R", obj); + return NULL; + } + else if (x == -1.0 && PyErr_Occurred()) { + return NULL; + } + else { + return PyFloat_FromDouble(x); + } +} + PyObject * PyFloat_FromString(PyObject *v) { - const char *s, *last, *end; - double x; + const char *s; PyObject *s_buffer = NULL; Py_ssize_t len; Py_buffer view = {NULL, NULL}; @@ -169,27 +201,8 @@ PyFloat_FromString(PyObject *v) Py_TYPE(v)->tp_name); return NULL; } - last = s + len; - /* strip space */ - while (s < last && Py_ISSPACE(*s)) - s++; - while (s < last - 1 && Py_ISSPACE(last[-1])) - last--; - /* We don't care about overflow or underflow. If the platform - * supports them, infinities and signed zeroes (on underflow) are - * fine. */ - x = PyOS_string_to_double(s, (char **)&end, NULL); - if (end != last) { - PyErr_Format(PyExc_ValueError, - "could not convert string to float: " - "%R", v); - result = NULL; - } - else if (x == -1.0 && PyErr_Occurred()) - result = NULL; - else - result = PyFloat_FromDouble(x); - + result = _Py_string_to_number_with_underscores(s, len, "float", v, v, + float_from_string_inner); PyBuffer_Release(&view); Py_XDECREF(s_buffer); return result; @@ -215,35 +228,49 @@ double PyFloat_AsDouble(PyObject *op) { PyNumberMethods *nb; - PyFloatObject *fo; + PyObject *res; double val; - if (op && PyFloat_Check(op)) - return PyFloat_AS_DOUBLE((PyFloatObject*) op); - if (op == NULL) { PyErr_BadArgument(); return -1; } - if ((nb = Py_TYPE(op)->tp_as_number) == NULL || nb->nb_float == NULL) { - PyErr_SetString(PyExc_TypeError, "a float is required"); - return -1; + if (PyFloat_Check(op)) { + return PyFloat_AS_DOUBLE(op); } - fo = (PyFloatObject*) (*nb->nb_float) (op); - if (fo == NULL) - return -1; - if (!PyFloat_Check(fo)) { - Py_DECREF(fo); - PyErr_SetString(PyExc_TypeError, - "nb_float should return float object"); + nb = Py_TYPE(op)->tp_as_number; + if (nb == NULL || nb->nb_float == NULL) { + PyErr_Format(PyExc_TypeError, "must be real number, not %.50s", + op->ob_type->tp_name); return -1; } - val = PyFloat_AS_DOUBLE(fo); - Py_DECREF(fo); + res = (*nb->nb_float) (op); + if (res == NULL) { + return -1; + } + if (!PyFloat_CheckExact(res)) { + if (!PyFloat_Check(res)) { + PyErr_Format(PyExc_TypeError, + "%.50s.__float__ returned non-float (type %.50s)", + op->ob_type->tp_name, res->ob_type->tp_name); + Py_DECREF(res); + return -1; + } + if (PyErr_WarnFormat(PyExc_DeprecationWarning, 1, + "%.50s.__float__ returned non-float (type %.50s). " + "The ability to return an instance of a strict subclass of float " + "is deprecated, and may be removed in a future version of Python.", + op->ob_type->tp_name, res->ob_type->tp_name)) { + Py_DECREF(res); + return -1; + } + } + val = PyFloat_AS_DOUBLE(res); + Py_DECREF(res); return val; } @@ -1195,7 +1222,7 @@ Return a hexadecimal representation of a floating-point number.\n\ static PyObject * float_fromhex(PyObject *cls, PyObject *arg) { - PyObject *result_as_float, *result; + PyObject *result; double x; long exp, top_exp, lsb, key_digit; char *s, *coeff_start, *s_store, *coeff_end, *exp_start, *s_end; @@ -1247,7 +1274,7 @@ float_fromhex(PyObject *cls, PyObject *arg) * exp+4*ndigits and exp-4*ndigits are within the range of a long. */ - s = _PyUnicode_AsStringAndSize(arg, &length); + s = PyUnicode_AsUTF8AndSize(arg, &length); if (s == NULL) return NULL; s_end = s + length; @@ -1410,11 +1437,10 @@ float_fromhex(PyObject *cls, PyObject *arg) s++; if (s != s_end) goto parse_error; - result_as_float = Py_BuildValue("(d)", negate ? -x : x); - if (result_as_float == NULL) - return NULL; - result = PyObject_CallObject(cls, result_as_float); - Py_DECREF(result_as_float); + result = PyFloat_FromDouble(negate ? -x : x); + if (cls != (PyObject *)&PyFloat_Type && result != NULL) { + Py_SETREF(result, PyObject_CallFunctionObjArgs(cls, result, NULL)); + } return result; overflow_error: @@ -1451,29 +1477,23 @@ float_as_integer_ratio(PyObject *v, PyObject *unused) int exponent; int i; - PyObject *prev; PyObject *py_exponent = NULL; PyObject *numerator = NULL; PyObject *denominator = NULL; PyObject *result_pair = NULL; PyNumberMethods *long_methods = PyLong_Type.tp_as_number; -#define INPLACE_UPDATE(obj, call) \ - prev = obj; \ - obj = call; \ - Py_DECREF(prev); \ - CONVERT_TO_DOUBLE(v, self); if (Py_IS_INFINITY(self)) { - PyErr_SetString(PyExc_OverflowError, - "Cannot pass infinity to float.as_integer_ratio."); - return NULL; + PyErr_SetString(PyExc_OverflowError, + "cannot convert Infinity to integer ratio"); + return NULL; } if (Py_IS_NAN(self)) { - PyErr_SetString(PyExc_ValueError, - "Cannot pass NaN to float.as_integer_ratio."); - return NULL; + PyErr_SetString(PyExc_ValueError, + "cannot convert NaN to integer ratio"); + return NULL; } PyFPE_START_PROTECT("as_integer_ratio", goto error); @@ -1489,29 +1509,31 @@ float_as_integer_ratio(PyObject *v, PyObject *unused) to be truncated by PyLong_FromDouble(). */ numerator = PyLong_FromDouble(float_part); - if (numerator == NULL) goto error; + if (numerator == NULL) + goto error; + denominator = PyLong_FromLong(1); + if (denominator == NULL) + goto error; + py_exponent = PyLong_FromLong(Py_ABS(exponent)); + if (py_exponent == NULL) + goto error; /* fold in 2**exponent */ - denominator = PyLong_FromLong(1); - py_exponent = PyLong_FromLong(labs((long)exponent)); - if (py_exponent == NULL) goto error; - INPLACE_UPDATE(py_exponent, - long_methods->nb_lshift(denominator, py_exponent)); - if (py_exponent == NULL) goto error; if (exponent > 0) { - INPLACE_UPDATE(numerator, - long_methods->nb_multiply(numerator, py_exponent)); - if (numerator == NULL) goto error; + Py_SETREF(numerator, + long_methods->nb_lshift(numerator, py_exponent)); + if (numerator == NULL) + goto error; } else { - Py_DECREF(denominator); - denominator = py_exponent; - py_exponent = NULL; + Py_SETREF(denominator, + long_methods->nb_lshift(denominator, py_exponent)); + if (denominator == NULL) + goto error; } result_pair = PyTuple_Pack(2, numerator, denominator); -#undef INPLACE_UPDATE error: Py_XDECREF(py_exponent); Py_XDECREF(denominator); @@ -1606,7 +1628,7 @@ float_getformat(PyTypeObject *v, PyObject* arg) Py_TYPE(arg)->tp_name); return NULL; } - s = _PyUnicode_AsString(arg); + s = PyUnicode_AsUTF8(arg); if (s == NULL) return NULL; if (strcmp(s, "double") == 0) { @@ -1966,8 +1988,120 @@ _PyFloat_DebugMallocStats(FILE *out) /*---------------------------------------------------------------------------- - * _PyFloat_{Pack,Unpack}{4,8}. See floatobject.h. + * _PyFloat_{Pack,Unpack}{2,4,8}. See floatobject.h. + * To match the NPY_HALF_ROUND_TIES_TO_EVEN behavior in: + * https://github.com/numpy/numpy/blob/master/numpy/core/src/npymath/halffloat.c + * We use: + * bits = (unsigned short)f; Note the truncation + * if ((f - bits > 0.5) || (f - bits == 0.5 && bits % 2)) { + * bits++; + * } */ + +int +_PyFloat_Pack2(double x, unsigned char *p, int le) +{ + unsigned char sign; + int e; + double f; + unsigned short bits; + int incr = 1; + + if (x == 0.0) { + sign = (copysign(1.0, x) == -1.0); + e = 0; + bits = 0; + } + else if (Py_IS_INFINITY(x)) { + sign = (x < 0.0); + e = 0x1f; + bits = 0; + } + else if (Py_IS_NAN(x)) { + /* There are 2046 distinct half-precision NaNs (1022 signaling and + 1024 quiet), but there are only two quiet NaNs that don't arise by + quieting a signaling NaN; we get those by setting the topmost bit + of the fraction field and clearing all other fraction bits. We + choose the one with the appropriate sign. */ + sign = (copysign(1.0, x) == -1.0); + e = 0x1f; + bits = 512; + } + else { + sign = (x < 0.0); + if (sign) { + x = -x; + } + + f = frexp(x, &e); + if (f < 0.5 || f >= 1.0) { + PyErr_SetString(PyExc_SystemError, + "frexp() result out of range"); + return -1; + } + + /* Normalize f to be in the range [1.0, 2.0) */ + f *= 2.0; + e--; + + if (e >= 16) { + goto Overflow; + } + else if (e < -25) { + /* |x| < 2**-25. Underflow to zero. */ + f = 0.0; + e = 0; + } + else if (e < -14) { + /* |x| < 2**-14. Gradual underflow */ + f = ldexp(f, 14 + e); + e = 0; + } + else /* if (!(e == 0 && f == 0.0)) */ { + e += 15; + f -= 1.0; /* Get rid of leading 1 */ + } + + f *= 1024.0; /* 2**10 */ + /* Round to even */ + bits = (unsigned short)f; /* Note the truncation */ + assert(bits < 1024); + assert(e < 31); + if ((f - bits > 0.5) || ((f - bits == 0.5) && (bits % 2 == 1))) { + ++bits; + if (bits == 1024) { + /* The carry propagated out of a string of 10 1 bits. */ + bits = 0; + ++e; + if (e == 31) + goto Overflow; + } + } + } + + bits |= (e << 10) | (sign << 15); + + /* Write out result. */ + if (le) { + p += 1; + incr = -1; + } + + /* First byte */ + *p = (unsigned char)((bits >> 8) & 0xFF); + p += incr; + + /* Second byte */ + *p = (unsigned char)(bits & 0xFF); + + return 0; + + Overflow: + PyErr_SetString(PyExc_OverflowError, + "float too large to pack with e format"); + return -1; +} + int _PyFloat_Pack4(double x, unsigned char *p, int le) { @@ -2203,6 +2337,76 @@ _PyFloat_Pack8(double x, unsigned char *p, int le) } double +_PyFloat_Unpack2(const unsigned char *p, int le) +{ + unsigned char sign; + int e; + unsigned int f; + double x; + int incr = 1; + + if (le) { + p += 1; + incr = -1; + } + + /* First byte */ + sign = (*p >> 7) & 1; + e = (*p & 0x7C) >> 2; + f = (*p & 0x03) << 8; + p += incr; + + /* Second byte */ + f |= *p; + + if (e == 0x1f) { +#ifdef PY_NO_SHORT_FLOAT_REPR + if (f == 0) { + /* Infinity */ + return sign ? -Py_HUGE_VAL : Py_HUGE_VAL; + } + else { + /* NaN */ +#ifdef Py_NAN + return sign ? -Py_NAN : Py_NAN; +#else + PyErr_SetString( + PyExc_ValueError, + "can't unpack IEEE 754 NaN " + "on platform that does not support NaNs"); + return -1; +#endif /* #ifdef Py_NAN */ + } +#else + if (f == 0) { + /* Infinity */ + return _Py_dg_infinity(sign); + } + else { + /* NaN */ + return _Py_dg_stdnan(sign); + } +#endif /* #ifdef PY_NO_SHORT_FLOAT_REPR */ + } + + x = (double)f / 1024.0; + + if (e == 0) { + e = -14; + } + else { + x += 1.0; + e -= 15; + } + x = ldexp(x, e); + + if (sign) + x = -x; + + return x; +} + +double _PyFloat_Unpack4(const unsigned char *p, int le) { if (float_format == unknown_format) { |