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#include <Python.h>
#define NPY_NO_DEPRECATED_API NPY_API_VERSION
#include "numpy/ndarraytypes.h"
#include "numpy/npy_math.h"
/* This is a backport of Py_SETREF */
#define NPY_SETREF(op, op2) \
do { \
PyObject *_py_tmp = (PyObject *)(op); \
(op) = (op2); \
Py_DECREF(_py_tmp); \
} while (0)
/*
* Heavily derived from PyLong_FromDouble
* Notably, we can't set the digits directly, so have to shift and or instead.
*/
NPY_VISIBILITY_HIDDEN PyObject *
npy_longdouble_to_PyLong(npy_longdouble ldval)
{
PyObject *v;
PyObject *l_chunk_size;
/*
* number of bits to extract at a time. CPython uses 30, but that's because
* it's tied to the internal long representation
*/
const int chunk_size = NPY_BITSOF_LONGLONG;
npy_longdouble frac;
int i, ndig, expo, neg;
neg = 0;
if (npy_isinf(ldval)) {
PyErr_SetString(PyExc_OverflowError,
"cannot convert longdouble infinity to integer");
return NULL;
}
if (npy_isnan(ldval)) {
PyErr_SetString(PyExc_ValueError,
"cannot convert longdouble NaN to integer");
return NULL;
}
if (ldval < 0.0) {
neg = 1;
ldval = -ldval;
}
frac = npy_frexpl(ldval, &expo); /* ldval = frac*2**expo; 0.0 <= frac < 1.0 */
v = PyLong_FromLong(0L);
if (v == NULL)
return NULL;
if (expo <= 0)
return v;
ndig = (expo-1) / chunk_size + 1;
l_chunk_size = PyLong_FromLong(chunk_size);
if (l_chunk_size == NULL) {
Py_DECREF(v);
return NULL;
}
/* Get the MSBs of the integral part of the float */
frac = npy_ldexpl(frac, (expo-1) % chunk_size + 1);
for (i = ndig; --i >= 0; ) {
npy_ulonglong chunk = (npy_ulonglong)frac;
PyObject *l_chunk;
/* v = v << chunk_size */
NPY_SETREF(v, PyNumber_Lshift(v, l_chunk_size));
if (v == NULL) {
goto done;
}
l_chunk = PyLong_FromUnsignedLongLong(chunk);
if (l_chunk == NULL) {
Py_DECREF(v);
v = NULL;
goto done;
}
/* v = v | chunk */
NPY_SETREF(v, PyNumber_Or(v, l_chunk));
Py_DECREF(l_chunk);
if (v == NULL) {
goto done;
}
/* Remove the msbs, and repeat */
frac = frac - (npy_longdouble) chunk;
frac = npy_ldexpl(frac, chunk_size);
}
/* v = -v */
if (neg) {
NPY_SETREF(v, PyNumber_Negative(v));
if (v == NULL) {
goto done;
}
}
done:
Py_DECREF(l_chunk_size);
return v;
}
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