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1254 lines
30 KiB
1254 lines
30 KiB
14 years ago
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/* Float object implementation */
|
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|
||
|
/* XXX There should be overflow checks here, but it's hard to check
|
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for any kind of float exception without losing portability. */
|
||
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|
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|
#include "Python.h"
|
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|
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|
#include <ctype.h>
|
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|
||
|
#if !defined(__STDC__) && !defined(macintosh)
|
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|
extern double fmod(double, double);
|
||
|
extern double pow(double, double);
|
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|
#endif
|
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||
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#if defined(sun) && !defined(__SVR4)
|
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/* On SunOS4.1 only libm.a exists. Make sure that references to all
|
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|
needed math functions exist in the executable, so that dynamic
|
||
|
loading of mathmodule does not fail. */
|
||
|
double (*_Py_math_funcs_hack[])() = {
|
||
|
acos, asin, atan, atan2, ceil, cos, cosh, exp, fabs, floor,
|
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|
fmod, log, log10, pow, sin, sinh, sqrt, tan, tanh
|
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|
};
|
||
|
#endif
|
||
|
|
||
|
/* Special free list -- see comments for same code in intobject.c. */
|
||
|
#define BLOCK_SIZE 1000 /* 1K less typical malloc overhead */
|
||
|
#define BHEAD_SIZE 8 /* Enough for a 64-bit pointer */
|
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|
#define N_FLOATOBJECTS ((BLOCK_SIZE - BHEAD_SIZE) / sizeof(PyFloatObject))
|
||
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|
||
|
struct _floatblock {
|
||
|
struct _floatblock *next;
|
||
|
PyFloatObject objects[N_FLOATOBJECTS];
|
||
|
};
|
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|
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typedef struct _floatblock PyFloatBlock;
|
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|
||
|
static PyFloatBlock *block_list = NULL;
|
||
|
static PyFloatObject *free_list = NULL;
|
||
|
|
||
|
static PyFloatObject *
|
||
|
fill_free_list(void)
|
||
|
{
|
||
|
PyFloatObject *p, *q;
|
||
|
/* XXX Float blocks escape the object heap. Use PyObject_MALLOC ??? */
|
||
|
p = (PyFloatObject *) PyMem_MALLOC(sizeof(PyFloatBlock));
|
||
|
if (p == NULL)
|
||
|
return (PyFloatObject *) PyErr_NoMemory();
|
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|
((PyFloatBlock *)p)->next = block_list;
|
||
|
block_list = (PyFloatBlock *)p;
|
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|
p = &((PyFloatBlock *)p)->objects[0];
|
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|
q = p + N_FLOATOBJECTS;
|
||
|
while (--q > p)
|
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|
q->ob_type = (struct _typeobject *)(q-1);
|
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|
q->ob_type = NULL;
|
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|
return p + N_FLOATOBJECTS - 1;
|
||
|
}
|
||
|
|
||
|
PyObject *
|
||
|
PyFloat_FromDouble(double fval)
|
||
|
{
|
||
|
register PyFloatObject *op;
|
||
|
if (free_list == NULL) {
|
||
|
if ((free_list = fill_free_list()) == NULL)
|
||
|
return NULL;
|
||
|
}
|
||
|
/* Inline PyObject_New */
|
||
|
op = free_list;
|
||
|
free_list = (PyFloatObject *)op->ob_type;
|
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|
PyObject_INIT(op, &PyFloat_Type);
|
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|
op->ob_fval = fval;
|
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|
return (PyObject *) op;
|
||
|
}
|
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|
|
||
|
/**************************************************************************
|
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|
RED_FLAG 22-Sep-2000 tim
|
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|
PyFloat_FromString's pend argument is braindead. Prior to this RED_FLAG,
|
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|
|
||
|
1. If v was a regular string, *pend was set to point to its terminating
|
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|
null byte. That's useless (the caller can find that without any
|
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|
help from this function!).
|
||
|
|
||
|
2. If v was a Unicode string, or an object convertible to a character
|
||
|
buffer, *pend was set to point into stack trash (the auto temp
|
||
|
vector holding the character buffer). That was downright dangerous.
|
||
|
|
||
|
Since we can't change the interface of a public API function, pend is
|
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|
still supported but now *officially* useless: if pend is not NULL,
|
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|
*pend is set to NULL.
|
||
|
**************************************************************************/
|
||
|
PyObject *
|
||
|
PyFloat_FromString(PyObject *v, char **pend)
|
||
|
{
|
||
|
const char *s, *last, *end;
|
||
|
double x;
|
||
|
char buffer[256]; /* for errors */
|
||
|
#ifdef Py_USING_UNICODE
|
||
|
char s_buffer[256]; /* for objects convertible to a char buffer */
|
||
|
#endif
|
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|
int len;
|
||
|
|
||
|
if (pend)
|
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|
*pend = NULL;
|
||
|
if (PyString_Check(v)) {
|
||
|
s = PyString_AS_STRING(v);
|
||
|
len = PyString_GET_SIZE(v);
|
||
|
}
|
||
|
#ifdef Py_USING_UNICODE
|
||
|
else if (PyUnicode_Check(v)) {
|
||
|
if (PyUnicode_GET_SIZE(v) >= sizeof(s_buffer)) {
|
||
|
PyErr_SetString(PyExc_ValueError,
|
||
|
"Unicode float() literal too long to convert");
|
||
|
return NULL;
|
||
|
}
|
||
|
if (PyUnicode_EncodeDecimal(PyUnicode_AS_UNICODE(v),
|
||
|
PyUnicode_GET_SIZE(v),
|
||
|
s_buffer,
|
||
|
NULL))
|
||
|
return NULL;
|
||
|
s = s_buffer;
|
||
|
len = (int)strlen(s);
|
||
|
}
|
||
|
#endif
|
||
|
else if (PyObject_AsCharBuffer(v, &s, &len)) {
|
||
|
PyErr_SetString(PyExc_TypeError,
|
||
|
"float() argument must be a string or a number");
|
||
|
return NULL;
|
||
|
}
|
||
|
|
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|
last = s + len;
|
||
|
while (*s && isspace(Py_CHARMASK(*s)))
|
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|
s++;
|
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|
if (*s == '\0') {
|
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|
PyErr_SetString(PyExc_ValueError, "empty string for float()");
|
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|
return NULL;
|
||
|
}
|
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|
/* We don't care about overflow or underflow. If the platform supports
|
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|
* them, infinities and signed zeroes (on underflow) are fine.
|
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|
* However, strtod can return 0 for denormalized numbers, where atof
|
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|
* does not. So (alas!) we special-case a zero result. Note that
|
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|
* whether strtod sets errno on underflow is not defined, so we can't
|
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|
* key off errno.
|
||
|
*/
|
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|
PyFPE_START_PROTECT("strtod", return NULL)
|
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|
x = strtod(s, (char **)&end);
|
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|
PyFPE_END_PROTECT(x)
|
||
|
errno = 0;
|
||
|
/* Believe it or not, Solaris 2.6 can move end *beyond* the null
|
||
|
byte at the end of the string, when the input is inf(inity). */
|
||
|
if (end > last)
|
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|
end = last;
|
||
|
if (end == s) {
|
||
|
PyOS_snprintf(buffer, sizeof(buffer),
|
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|
"invalid literal for float(): %.200s", s);
|
||
|
PyErr_SetString(PyExc_ValueError, buffer);
|
||
|
return NULL;
|
||
|
}
|
||
|
/* Since end != s, the platform made *some* kind of sense out
|
||
|
of the input. Trust it. */
|
||
|
while (*end && isspace(Py_CHARMASK(*end)))
|
||
|
end++;
|
||
|
if (*end != '\0') {
|
||
|
PyOS_snprintf(buffer, sizeof(buffer),
|
||
|
"invalid literal for float(): %.200s", s);
|
||
|
PyErr_SetString(PyExc_ValueError, buffer);
|
||
|
return NULL;
|
||
|
}
|
||
|
else if (end != last) {
|
||
|
PyErr_SetString(PyExc_ValueError,
|
||
|
"null byte in argument for float()");
|
||
|
return NULL;
|
||
|
}
|
||
|
if (x == 0.0) {
|
||
|
/* See above -- may have been strtod being anal
|
||
|
about denorms. */
|
||
|
PyFPE_START_PROTECT("atof", return NULL)
|
||
|
x = atof(s);
|
||
|
PyFPE_END_PROTECT(x)
|
||
|
errno = 0; /* whether atof ever set errno is undefined */
|
||
|
}
|
||
|
return PyFloat_FromDouble(x);
|
||
|
}
|
||
|
|
||
|
static void
|
||
|
float_dealloc(PyFloatObject *op)
|
||
|
{
|
||
|
if (PyFloat_CheckExact(op)) {
|
||
|
op->ob_type = (struct _typeobject *)free_list;
|
||
|
free_list = op;
|
||
|
}
|
||
|
else
|
||
|
op->ob_type->tp_free((PyObject *)op);
|
||
|
}
|
||
|
|
||
|
double
|
||
|
PyFloat_AsDouble(PyObject *op)
|
||
|
{
|
||
|
PyNumberMethods *nb;
|
||
|
PyFloatObject *fo;
|
||
|
double val;
|
||
|
|
||
|
if (op && PyFloat_Check(op))
|
||
|
return PyFloat_AS_DOUBLE((PyFloatObject*) op);
|
||
|
|
||
|
if (op == NULL) {
|
||
|
PyErr_BadArgument();
|
||
|
return -1;
|
||
|
}
|
||
|
|
||
|
if ((nb = op->ob_type->tp_as_number) == NULL || nb->nb_float == NULL) {
|
||
|
PyErr_SetString(PyExc_TypeError, "a float is required");
|
||
|
return -1;
|
||
|
}
|
||
|
|
||
|
fo = (PyFloatObject*) (*nb->nb_float) (op);
|
||
|
if (fo == NULL)
|
||
|
return -1;
|
||
|
if (!PyFloat_Check(fo)) {
|
||
|
PyErr_SetString(PyExc_TypeError,
|
||
|
"nb_float should return float object");
|
||
|
return -1;
|
||
|
}
|
||
|
|
||
|
val = PyFloat_AS_DOUBLE(fo);
|
||
|
Py_DECREF(fo);
|
||
|
|
||
|
return val;
|
||
|
}
|
||
|
|
||
|
/* Methods */
|
||
|
|
||
|
static void
|
||
|
format_float(char *buf, size_t buflen, PyFloatObject *v, int precision)
|
||
|
{
|
||
|
register char *cp;
|
||
|
/* Subroutine for float_repr and float_print.
|
||
|
We want float numbers to be recognizable as such,
|
||
|
i.e., they should contain a decimal point or an exponent.
|
||
|
However, %g may print the number as an integer;
|
||
|
in such cases, we append ".0" to the string. */
|
||
|
|
||
|
assert(PyFloat_Check(v));
|
||
|
PyOS_snprintf(buf, buflen, "%.*g", precision, v->ob_fval);
|
||
|
cp = buf;
|
||
|
if (*cp == '-')
|
||
|
cp++;
|
||
|
for (; *cp != '\0'; cp++) {
|
||
|
/* Any non-digit means it's not an integer;
|
||
|
this takes care of NAN and INF as well. */
|
||
|
if (!isdigit(Py_CHARMASK(*cp)))
|
||
|
break;
|
||
|
}
|
||
|
if (*cp == '\0') {
|
||
|
*cp++ = '.';
|
||
|
*cp++ = '0';
|
||
|
*cp++ = '\0';
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* XXX PyFloat_AsStringEx should not be a public API function (for one
|
||
|
XXX thing, its signature passes a buffer without a length; for another,
|
||
|
XXX it isn't useful outside this file).
|
||
|
*/
|
||
|
void
|
||
|
PyFloat_AsStringEx(char *buf, PyFloatObject *v, int precision)
|
||
|
{
|
||
|
format_float(buf, 100, v, precision);
|
||
|
}
|
||
|
|
||
|
/* Macro and helper that convert PyObject obj to a C double and store
|
||
|
the value in dbl; this replaces the functionality of the coercion
|
||
|
slot function. If conversion to double raises an exception, obj is
|
||
|
set to NULL, and the function invoking this macro returns NULL. If
|
||
|
obj is not of float, int or long type, Py_NotImplemented is incref'ed,
|
||
|
stored in obj, and returned from the function invoking this macro.
|
||
|
*/
|
||
|
#define CONVERT_TO_DOUBLE(obj, dbl) \
|
||
|
if (PyFloat_Check(obj)) \
|
||
|
dbl = PyFloat_AS_DOUBLE(obj); \
|
||
|
else if (convert_to_double(&(obj), &(dbl)) < 0) \
|
||
|
return obj;
|
||
|
|
||
|
static int
|
||
|
convert_to_double(PyObject **v, double *dbl)
|
||
|
{
|
||
|
register PyObject *obj = *v;
|
||
|
|
||
|
if (PyInt_Check(obj)) {
|
||
|
*dbl = (double)PyInt_AS_LONG(obj);
|
||
|
}
|
||
|
else if (PyLong_Check(obj)) {
|
||
|
*dbl = PyLong_AsDouble(obj);
|
||
|
if (*dbl == -1.0 && PyErr_Occurred()) {
|
||
|
*v = NULL;
|
||
|
return -1;
|
||
|
}
|
||
|
}
|
||
|
else {
|
||
|
Py_INCREF(Py_NotImplemented);
|
||
|
*v = Py_NotImplemented;
|
||
|
return -1;
|
||
|
}
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
/* Precisions used by repr() and str(), respectively.
|
||
|
|
||
|
The repr() precision (17 significant decimal digits) is the minimal number
|
||
|
that is guaranteed to have enough precision so that if the number is read
|
||
|
back in the exact same binary value is recreated. This is true for IEEE
|
||
|
floating point by design, and also happens to work for all other modern
|
||
|
hardware.
|
||
|
|
||
|
The str() precision is chosen so that in most cases, the rounding noise
|
||
|
created by various operations is suppressed, while giving plenty of
|
||
|
precision for practical use.
|
||
|
|
||
|
*/
|
||
|
|
||
|
#define PREC_REPR 17
|
||
|
#define PREC_STR 12
|
||
|
|
||
|
/* XXX PyFloat_AsString and PyFloat_AsReprString should be deprecated:
|
||
|
XXX they pass a char buffer without passing a length.
|
||
|
*/
|
||
|
void
|
||
|
PyFloat_AsString(char *buf, PyFloatObject *v)
|
||
|
{
|
||
|
format_float(buf, 100, v, PREC_STR);
|
||
|
}
|
||
|
|
||
|
void
|
||
|
PyFloat_AsReprString(char *buf, PyFloatObject *v)
|
||
|
{
|
||
|
format_float(buf, 100, v, PREC_REPR);
|
||
|
}
|
||
|
|
||
|
/* ARGSUSED */
|
||
|
static int
|
||
|
float_print(PyFloatObject *v, FILE *fp, int flags)
|
||
|
{
|
||
|
char buf[100];
|
||
|
format_float(buf, sizeof(buf), v,
|
||
|
(flags & Py_PRINT_RAW) ? PREC_STR : PREC_REPR);
|
||
|
fputs(buf, fp);
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static PyObject *
|
||
|
float_repr(PyFloatObject *v)
|
||
|
{
|
||
|
char buf[100];
|
||
|
format_float(buf, sizeof(buf), v, PREC_REPR);
|
||
|
return PyString_FromString(buf);
|
||
|
}
|
||
|
|
||
|
static PyObject *
|
||
|
float_str(PyFloatObject *v)
|
||
|
{
|
||
|
char buf[100];
|
||
|
format_float(buf, sizeof(buf), v, PREC_STR);
|
||
|
return PyString_FromString(buf);
|
||
|
}
|
||
|
|
||
|
static int
|
||
|
float_compare(PyFloatObject *v, PyFloatObject *w)
|
||
|
{
|
||
|
double i = v->ob_fval;
|
||
|
double j = w->ob_fval;
|
||
|
return (i < j) ? -1 : (i > j) ? 1 : 0;
|
||
|
}
|
||
|
|
||
|
static long
|
||
|
float_hash(PyFloatObject *v)
|
||
|
{
|
||
|
return _Py_HashDouble(v->ob_fval);
|
||
|
}
|
||
|
|
||
|
static PyObject *
|
||
|
float_add(PyObject *v, PyObject *w)
|
||
|
{
|
||
|
double a,b;
|
||
|
CONVERT_TO_DOUBLE(v, a);
|
||
|
CONVERT_TO_DOUBLE(w, b);
|
||
|
PyFPE_START_PROTECT("add", return 0)
|
||
|
a = a + b;
|
||
|
PyFPE_END_PROTECT(a)
|
||
|
return PyFloat_FromDouble(a);
|
||
|
}
|
||
|
|
||
|
static PyObject *
|
||
|
float_sub(PyObject *v, PyObject *w)
|
||
|
{
|
||
|
double a,b;
|
||
|
CONVERT_TO_DOUBLE(v, a);
|
||
|
CONVERT_TO_DOUBLE(w, b);
|
||
|
PyFPE_START_PROTECT("subtract", return 0)
|
||
|
a = a - b;
|
||
|
PyFPE_END_PROTECT(a)
|
||
|
return PyFloat_FromDouble(a);
|
||
|
}
|
||
|
|
||
|
static PyObject *
|
||
|
float_mul(PyObject *v, PyObject *w)
|
||
|
{
|
||
|
double a,b;
|
||
|
CONVERT_TO_DOUBLE(v, a);
|
||
|
CONVERT_TO_DOUBLE(w, b);
|
||
|
PyFPE_START_PROTECT("multiply", return 0)
|
||
|
a = a * b;
|
||
|
PyFPE_END_PROTECT(a)
|
||
|
return PyFloat_FromDouble(a);
|
||
|
}
|
||
|
|
||
|
static PyObject *
|
||
|
float_div(PyObject *v, PyObject *w)
|
||
|
{
|
||
|
double a,b;
|
||
|
CONVERT_TO_DOUBLE(v, a);
|
||
|
CONVERT_TO_DOUBLE(w, b);
|
||
|
if (b == 0.0) {
|
||
|
PyErr_SetString(PyExc_ZeroDivisionError, "float division");
|
||
|
return NULL;
|
||
|
}
|
||
|
PyFPE_START_PROTECT("divide", return 0)
|
||
|
a = a / b;
|
||
|
PyFPE_END_PROTECT(a)
|
||
|
return PyFloat_FromDouble(a);
|
||
|
}
|
||
|
|
||
|
static PyObject *
|
||
|
float_classic_div(PyObject *v, PyObject *w)
|
||
|
{
|
||
|
double a,b;
|
||
|
CONVERT_TO_DOUBLE(v, a);
|
||
|
CONVERT_TO_DOUBLE(w, b);
|
||
|
if (Py_DivisionWarningFlag >= 2 &&
|
||
|
PyErr_Warn(PyExc_DeprecationWarning, "classic float division") < 0)
|
||
|
return NULL;
|
||
|
if (b == 0.0) {
|
||
|
PyErr_SetString(PyExc_ZeroDivisionError, "float division");
|
||
|
return NULL;
|
||
|
}
|
||
|
PyFPE_START_PROTECT("divide", return 0)
|
||
|
a = a / b;
|
||
|
PyFPE_END_PROTECT(a)
|
||
|
return PyFloat_FromDouble(a);
|
||
|
}
|
||
|
|
||
|
static PyObject *
|
||
|
float_rem(PyObject *v, PyObject *w)
|
||
|
{
|
||
|
double vx, wx;
|
||
|
double mod;
|
||
|
CONVERT_TO_DOUBLE(v, vx);
|
||
|
CONVERT_TO_DOUBLE(w, wx);
|
||
|
if (wx == 0.0) {
|
||
|
PyErr_SetString(PyExc_ZeroDivisionError, "float modulo");
|
||
|
return NULL;
|
||
|
}
|
||
|
PyFPE_START_PROTECT("modulo", return 0)
|
||
|
mod = fmod(vx, wx);
|
||
|
/* note: checking mod*wx < 0 is incorrect -- underflows to
|
||
|
0 if wx < sqrt(smallest nonzero double) */
|
||
|
if (mod && ((wx < 0) != (mod < 0))) {
|
||
|
mod += wx;
|
||
|
}
|
||
|
PyFPE_END_PROTECT(mod)
|
||
|
return PyFloat_FromDouble(mod);
|
||
|
}
|
||
|
|
||
|
static PyObject *
|
||
|
float_divmod(PyObject *v, PyObject *w)
|
||
|
{
|
||
|
double vx, wx;
|
||
|
double div, mod, floordiv;
|
||
|
CONVERT_TO_DOUBLE(v, vx);
|
||
|
CONVERT_TO_DOUBLE(w, wx);
|
||
|
if (wx == 0.0) {
|
||
|
PyErr_SetString(PyExc_ZeroDivisionError, "float divmod()");
|
||
|
return NULL;
|
||
|
}
|
||
|
PyFPE_START_PROTECT("divmod", return 0)
|
||
|
mod = fmod(vx, wx);
|
||
|
/* fmod is typically exact, so vx-mod is *mathematically* an
|
||
|
exact multiple of wx. But this is fp arithmetic, and fp
|
||
|
vx - mod is an approximation; the result is that div may
|
||
|
not be an exact integral value after the division, although
|
||
|
it will always be very close to one.
|
||
|
*/
|
||
|
div = (vx - mod) / wx;
|
||
|
if (mod) {
|
||
|
/* ensure the remainder has the same sign as the denominator */
|
||
|
if ((wx < 0) != (mod < 0)) {
|
||
|
mod += wx;
|
||
|
div -= 1.0;
|
||
|
}
|
||
|
}
|
||
|
else {
|
||
|
/* the remainder is zero, and in the presence of signed zeroes
|
||
|
fmod returns different results across platforms; ensure
|
||
|
it has the same sign as the denominator; we'd like to do
|
||
|
"mod = wx * 0.0", but that may get optimized away */
|
||
|
mod *= mod; /* hide "mod = +0" from optimizer */
|
||
|
if (wx < 0.0)
|
||
|
mod = -mod;
|
||
|
}
|
||
|
/* snap quotient to nearest integral value */
|
||
|
if (div) {
|
||
|
floordiv = floor(div);
|
||
|
if (div - floordiv > 0.5)
|
||
|
floordiv += 1.0;
|
||
|
}
|
||
|
else {
|
||
|
/* div is zero - get the same sign as the true quotient */
|
||
|
div *= div; /* hide "div = +0" from optimizers */
|
||
|
floordiv = div * vx / wx; /* zero w/ sign of vx/wx */
|
||
|
}
|
||
|
PyFPE_END_PROTECT(floordiv)
|
||
|
return Py_BuildValue("(dd)", floordiv, mod);
|
||
|
}
|
||
|
|
||
|
static PyObject *
|
||
|
float_floor_div(PyObject *v, PyObject *w)
|
||
|
{
|
||
|
PyObject *t, *r;
|
||
|
|
||
|
t = float_divmod(v, w);
|
||
|
if (t == NULL || t == Py_NotImplemented)
|
||
|
return t;
|
||
|
assert(PyTuple_CheckExact(t));
|
||
|
r = PyTuple_GET_ITEM(t, 0);
|
||
|
Py_INCREF(r);
|
||
|
Py_DECREF(t);
|
||
|
return r;
|
||
|
}
|
||
|
|
||
|
static PyObject *
|
||
|
float_pow(PyObject *v, PyObject *w, PyObject *z)
|
||
|
{
|
||
|
double iv, iw, ix;
|
||
|
|
||
|
if ((PyObject *)z != Py_None) {
|
||
|
PyErr_SetString(PyExc_TypeError, "pow() 3rd argument not "
|
||
|
"allowed unless all arguments are integers");
|
||
|
return NULL;
|
||
|
}
|
||
|
|
||
|
CONVERT_TO_DOUBLE(v, iv);
|
||
|
CONVERT_TO_DOUBLE(w, iw);
|
||
|
|
||
|
/* Sort out special cases here instead of relying on pow() */
|
||
|
if (iw == 0) { /* v**0 is 1, even 0**0 */
|
||
|
PyFPE_START_PROTECT("pow", return NULL)
|
||
|
if ((PyObject *)z != Py_None) {
|
||
|
double iz;
|
||
|
CONVERT_TO_DOUBLE(z, iz);
|
||
|
ix = fmod(1.0, iz);
|
||
|
if (ix != 0 && iz < 0)
|
||
|
ix += iz;
|
||
|
}
|
||
|
else
|
||
|
ix = 1.0;
|
||
|
PyFPE_END_PROTECT(ix)
|
||
|
return PyFloat_FromDouble(ix);
|
||
|
}
|
||
|
if (iv == 0.0) { /* 0**w is error if w<0, else 1 */
|
||
|
if (iw < 0.0) {
|
||
|
PyErr_SetString(PyExc_ZeroDivisionError,
|
||
|
"0.0 cannot be raised to a negative power");
|
||
|
return NULL;
|
||
|
}
|
||
|
return PyFloat_FromDouble(0.0);
|
||
|
}
|
||
|
if (iv < 0.0) {
|
||
|
/* Whether this is an error is a mess, and bumps into libm
|
||
|
* bugs so we have to figure it out ourselves.
|
||
|
*/
|
||
|
if (iw != floor(iw)) {
|
||
|
PyErr_SetString(PyExc_ValueError, "negative number "
|
||
|
"cannot be raised to a fractional power");
|
||
|
return NULL;
|
||
|
}
|
||
|
/* iw is an exact integer, albeit perhaps a very large one.
|
||
|
* -1 raised to an exact integer should never be exceptional.
|
||
|
* Alas, some libms (chiefly glibc as of early 2003) return
|
||
|
* NaN and set EDOM on pow(-1, large_int) if the int doesn't
|
||
|
* happen to be representable in a *C* integer. That's a
|
||
|
* bug; we let that slide in math.pow() (which currently
|
||
|
* reflects all platform accidents), but not for Python's **.
|
||
|
*/
|
||
|
if (iv == -1.0 && !Py_IS_INFINITY(iw) && iw == iw) {
|
||
|
/* XXX the "iw == iw" was to weed out NaNs. This
|
||
|
* XXX doesn't actually work on all platforms.
|
||
|
*/
|
||
|
/* Return 1 if iw is even, -1 if iw is odd; there's
|
||
|
* no guarantee that any C integral type is big
|
||
|
* enough to hold iw, so we have to check this
|
||
|
* indirectly.
|
||
|
*/
|
||
|
ix = floor(iw * 0.5) * 2.0;
|
||
|
return PyFloat_FromDouble(ix == iw ? 1.0 : -1.0);
|
||
|
}
|
||
|
/* Else iv != -1.0, and overflow or underflow are possible.
|
||
|
* Unless we're to write pow() ourselves, we have to trust
|
||
|
* the platform to do this correctly.
|
||
|
*/
|
||
|
}
|
||
|
errno = 0;
|
||
|
PyFPE_START_PROTECT("pow", return NULL)
|
||
|
ix = pow(iv, iw);
|
||
|
PyFPE_END_PROTECT(ix)
|
||
|
Py_ADJUST_ERANGE1(ix);
|
||
|
if (errno != 0) {
|
||
|
/* We don't expect any errno value other than ERANGE, but
|
||
|
* the range of libm bugs appears unbounded.
|
||
|
*/
|
||
|
PyErr_SetFromErrno(errno == ERANGE ? PyExc_OverflowError :
|
||
|
PyExc_ValueError);
|
||
|
return NULL;
|
||
|
}
|
||
|
return PyFloat_FromDouble(ix);
|
||
|
}
|
||
|
|
||
|
static PyObject *
|
||
|
float_neg(PyFloatObject *v)
|
||
|
{
|
||
|
return PyFloat_FromDouble(-v->ob_fval);
|
||
|
}
|
||
|
|
||
|
static PyObject *
|
||
|
float_pos(PyFloatObject *v)
|
||
|
{
|
||
|
if (PyFloat_CheckExact(v)) {
|
||
|
Py_INCREF(v);
|
||
|
return (PyObject *)v;
|
||
|
}
|
||
|
else
|
||
|
return PyFloat_FromDouble(v->ob_fval);
|
||
|
}
|
||
|
|
||
|
static PyObject *
|
||
|
float_abs(PyFloatObject *v)
|
||
|
{
|
||
|
return PyFloat_FromDouble(fabs(v->ob_fval));
|
||
|
}
|
||
|
|
||
|
static int
|
||
|
float_nonzero(PyFloatObject *v)
|
||
|
{
|
||
|
return v->ob_fval != 0.0;
|
||
|
}
|
||
|
|
||
|
static int
|
||
|
float_coerce(PyObject **pv, PyObject **pw)
|
||
|
{
|
||
|
if (PyInt_Check(*pw)) {
|
||
|
long x = PyInt_AsLong(*pw);
|
||
|
*pw = PyFloat_FromDouble((double)x);
|
||
|
Py_INCREF(*pv);
|
||
|
return 0;
|
||
|
}
|
||
|
else if (PyLong_Check(*pw)) {
|
||
|
double x = PyLong_AsDouble(*pw);
|
||
|
if (x == -1.0 && PyErr_Occurred())
|
||
|
return -1;
|
||
|
*pw = PyFloat_FromDouble(x);
|
||
|
Py_INCREF(*pv);
|
||
|
return 0;
|
||
|
}
|
||
|
else if (PyFloat_Check(*pw)) {
|
||
|
Py_INCREF(*pv);
|
||
|
Py_INCREF(*pw);
|
||
|
return 0;
|
||
|
}
|
||
|
return 1; /* Can't do it */
|
||
|
}
|
||
|
|
||
|
static PyObject *
|
||
|
float_long(PyObject *v)
|
||
|
{
|
||
|
double x = PyFloat_AsDouble(v);
|
||
|
return PyLong_FromDouble(x);
|
||
|
}
|
||
|
|
||
|
static PyObject *
|
||
|
float_int(PyObject *v)
|
||
|
{
|
||
|
double x = PyFloat_AsDouble(v);
|
||
|
double wholepart; /* integral portion of x, rounded toward 0 */
|
||
|
|
||
|
(void)modf(x, &wholepart);
|
||
|
/* Try to get out cheap if this fits in a Python int. The attempt
|
||
|
* to cast to long must be protected, as C doesn't define what
|
||
|
* happens if the double is too big to fit in a long. Some rare
|
||
|
* systems raise an exception then (RISCOS was mentioned as one,
|
||
|
* and someone using a non-default option on Sun also bumped into
|
||
|
* that). Note that checking for >= and <= LONG_{MIN,MAX} would
|
||
|
* still be vulnerable: if a long has more bits of precision than
|
||
|
* a double, casting MIN/MAX to double may yield an approximation,
|
||
|
* and if that's rounded up, then, e.g., wholepart=LONG_MAX+1 would
|
||
|
* yield true from the C expression wholepart<=LONG_MAX, despite
|
||
|
* that wholepart is actually greater than LONG_MAX.
|
||
|
*/
|
||
|
if (LONG_MIN < wholepart && wholepart < LONG_MAX) {
|
||
|
const long aslong = (long)wholepart;
|
||
|
return PyInt_FromLong(aslong);
|
||
|
}
|
||
|
return PyLong_FromDouble(wholepart);
|
||
|
}
|
||
|
|
||
|
static PyObject *
|
||
|
float_float(PyObject *v)
|
||
|
{
|
||
|
Py_INCREF(v);
|
||
|
return v;
|
||
|
}
|
||
|
|
||
|
|
||
|
static PyObject *
|
||
|
float_subtype_new(PyTypeObject *type, PyObject *args, PyObject *kwds);
|
||
|
|
||
|
static PyObject *
|
||
|
float_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
|
||
|
{
|
||
|
PyObject *x = Py_False; /* Integer zero */
|
||
|
static char *kwlist[] = {"x", 0};
|
||
|
|
||
|
if (type != &PyFloat_Type)
|
||
|
return float_subtype_new(type, args, kwds); /* Wimp out */
|
||
|
if (!PyArg_ParseTupleAndKeywords(args, kwds, "|O:float", kwlist, &x))
|
||
|
return NULL;
|
||
|
if (PyString_Check(x))
|
||
|
return PyFloat_FromString(x, NULL);
|
||
|
return PyNumber_Float(x);
|
||
|
}
|
||
|
|
||
|
/* Wimpy, slow approach to tp_new calls for subtypes of float:
|
||
|
first create a regular float from whatever arguments we got,
|
||
|
then allocate a subtype instance and initialize its ob_fval
|
||
|
from the regular float. The regular float is then thrown away.
|
||
|
*/
|
||
|
static PyObject *
|
||
|
float_subtype_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
|
||
|
{
|
||
|
PyObject *tmp, *new;
|
||
|
|
||
|
assert(PyType_IsSubtype(type, &PyFloat_Type));
|
||
|
tmp = float_new(&PyFloat_Type, args, kwds);
|
||
|
if (tmp == NULL)
|
||
|
return NULL;
|
||
|
assert(PyFloat_CheckExact(tmp));
|
||
|
new = type->tp_alloc(type, 0);
|
||
|
if (new == NULL) {
|
||
|
Py_DECREF(tmp);
|
||
|
return NULL;
|
||
|
}
|
||
|
((PyFloatObject *)new)->ob_fval = ((PyFloatObject *)tmp)->ob_fval;
|
||
|
Py_DECREF(tmp);
|
||
|
return new;
|
||
|
}
|
||
|
|
||
|
static PyObject *
|
||
|
float_getnewargs(PyFloatObject *v)
|
||
|
{
|
||
|
return Py_BuildValue("(d)", v->ob_fval);
|
||
|
}
|
||
|
|
||
|
static PyMethodDef float_methods[] = {
|
||
|
{"__getnewargs__", (PyCFunction)float_getnewargs, METH_NOARGS},
|
||
|
{NULL, NULL} /* sentinel */
|
||
|
};
|
||
|
|
||
|
PyDoc_STRVAR(float_doc,
|
||
|
"float(x) -> floating point number\n\
|
||
|
\n\
|
||
|
Convert a string or number to a floating point number, if possible.");
|
||
|
|
||
|
|
||
|
static PyNumberMethods float_as_number = {
|
||
|
(binaryfunc)float_add, /*nb_add*/
|
||
|
(binaryfunc)float_sub, /*nb_subtract*/
|
||
|
(binaryfunc)float_mul, /*nb_multiply*/
|
||
|
(binaryfunc)float_classic_div, /*nb_divide*/
|
||
|
(binaryfunc)float_rem, /*nb_remainder*/
|
||
|
(binaryfunc)float_divmod, /*nb_divmod*/
|
||
|
(ternaryfunc)float_pow, /*nb_power*/
|
||
|
(unaryfunc)float_neg, /*nb_negative*/
|
||
|
(unaryfunc)float_pos, /*nb_positive*/
|
||
|
(unaryfunc)float_abs, /*nb_absolute*/
|
||
|
(inquiry)float_nonzero, /*nb_nonzero*/
|
||
|
0, /*nb_invert*/
|
||
|
0, /*nb_lshift*/
|
||
|
0, /*nb_rshift*/
|
||
|
0, /*nb_and*/
|
||
|
0, /*nb_xor*/
|
||
|
0, /*nb_or*/
|
||
|
(coercion)float_coerce, /*nb_coerce*/
|
||
|
(unaryfunc)float_int, /*nb_int*/
|
||
|
(unaryfunc)float_long, /*nb_long*/
|
||
|
(unaryfunc)float_float, /*nb_float*/
|
||
|
0, /* nb_oct */
|
||
|
0, /* nb_hex */
|
||
|
0, /* nb_inplace_add */
|
||
|
0, /* nb_inplace_subtract */
|
||
|
0, /* nb_inplace_multiply */
|
||
|
0, /* nb_inplace_divide */
|
||
|
0, /* nb_inplace_remainder */
|
||
|
0, /* nb_inplace_power */
|
||
|
0, /* nb_inplace_lshift */
|
||
|
0, /* nb_inplace_rshift */
|
||
|
0, /* nb_inplace_and */
|
||
|
0, /* nb_inplace_xor */
|
||
|
0, /* nb_inplace_or */
|
||
|
float_floor_div, /* nb_floor_divide */
|
||
|
float_div, /* nb_true_divide */
|
||
|
0, /* nb_inplace_floor_divide */
|
||
|
0, /* nb_inplace_true_divide */
|
||
|
};
|
||
|
|
||
|
PyTypeObject PyFloat_Type = {
|
||
|
PyObject_HEAD_INIT(&PyType_Type)
|
||
|
0,
|
||
|
"float",
|
||
|
sizeof(PyFloatObject),
|
||
|
0,
|
||
|
(destructor)float_dealloc, /* tp_dealloc */
|
||
|
(printfunc)float_print, /* tp_print */
|
||
|
0, /* tp_getattr */
|
||
|
0, /* tp_setattr */
|
||
|
(cmpfunc)float_compare, /* tp_compare */
|
||
|
(reprfunc)float_repr, /* tp_repr */
|
||
|
&float_as_number, /* tp_as_number */
|
||
|
0, /* tp_as_sequence */
|
||
|
0, /* tp_as_mapping */
|
||
|
(hashfunc)float_hash, /* tp_hash */
|
||
|
0, /* tp_call */
|
||
|
(reprfunc)float_str, /* tp_str */
|
||
|
PyObject_GenericGetAttr, /* tp_getattro */
|
||
|
0, /* tp_setattro */
|
||
|
0, /* tp_as_buffer */
|
||
|
Py_TPFLAGS_DEFAULT | Py_TPFLAGS_CHECKTYPES |
|
||
|
Py_TPFLAGS_BASETYPE, /* tp_flags */
|
||
|
float_doc, /* tp_doc */
|
||
|
0, /* tp_traverse */
|
||
|
0, /* tp_clear */
|
||
|
0, /* tp_richcompare */
|
||
|
0, /* tp_weaklistoffset */
|
||
|
0, /* tp_iter */
|
||
|
0, /* tp_iternext */
|
||
|
float_methods, /* tp_methods */
|
||
|
0, /* tp_members */
|
||
|
0, /* tp_getset */
|
||
|
0, /* tp_base */
|
||
|
0, /* tp_dict */
|
||
|
0, /* tp_descr_get */
|
||
|
0, /* tp_descr_set */
|
||
|
0, /* tp_dictoffset */
|
||
|
0, /* tp_init */
|
||
|
0, /* tp_alloc */
|
||
|
float_new, /* tp_new */
|
||
|
};
|
||
|
|
||
|
void
|
||
|
PyFloat_Fini(void)
|
||
|
{
|
||
|
PyFloatObject *p;
|
||
|
PyFloatBlock *list, *next;
|
||
|
int i;
|
||
|
int bc, bf; /* block count, number of freed blocks */
|
||
|
int frem, fsum; /* remaining unfreed floats per block, total */
|
||
|
|
||
|
bc = 0;
|
||
|
bf = 0;
|
||
|
fsum = 0;
|
||
|
list = block_list;
|
||
|
block_list = NULL;
|
||
|
free_list = NULL;
|
||
|
while (list != NULL) {
|
||
|
bc++;
|
||
|
frem = 0;
|
||
|
for (i = 0, p = &list->objects[0];
|
||
|
i < N_FLOATOBJECTS;
|
||
|
i++, p++) {
|
||
|
if (PyFloat_CheckExact(p) && p->ob_refcnt != 0)
|
||
|
frem++;
|
||
|
}
|
||
|
next = list->next;
|
||
|
if (frem) {
|
||
|
list->next = block_list;
|
||
|
block_list = list;
|
||
|
for (i = 0, p = &list->objects[0];
|
||
|
i < N_FLOATOBJECTS;
|
||
|
i++, p++) {
|
||
|
if (!PyFloat_CheckExact(p) ||
|
||
|
p->ob_refcnt == 0) {
|
||
|
p->ob_type = (struct _typeobject *)
|
||
|
free_list;
|
||
|
free_list = p;
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
else {
|
||
|
PyMem_FREE(list); /* XXX PyObject_FREE ??? */
|
||
|
bf++;
|
||
|
}
|
||
|
fsum += frem;
|
||
|
list = next;
|
||
|
}
|
||
|
if (!Py_VerboseFlag)
|
||
|
return;
|
||
|
fprintf(stderr, "# cleanup floats");
|
||
|
if (!fsum) {
|
||
|
fprintf(stderr, "\n");
|
||
|
}
|
||
|
else {
|
||
|
fprintf(stderr,
|
||
|
": %d unfreed float%s in %d out of %d block%s\n",
|
||
|
fsum, fsum == 1 ? "" : "s",
|
||
|
bc - bf, bc, bc == 1 ? "" : "s");
|
||
|
}
|
||
|
if (Py_VerboseFlag > 1) {
|
||
|
list = block_list;
|
||
|
while (list != NULL) {
|
||
|
for (i = 0, p = &list->objects[0];
|
||
|
i < N_FLOATOBJECTS;
|
||
|
i++, p++) {
|
||
|
if (PyFloat_CheckExact(p) &&
|
||
|
p->ob_refcnt != 0) {
|
||
|
char buf[100];
|
||
|
PyFloat_AsString(buf, p);
|
||
|
fprintf(stderr,
|
||
|
"# <float at %p, refcnt=%d, val=%s>\n",
|
||
|
p, p->ob_refcnt, buf);
|
||
|
}
|
||
|
}
|
||
|
list = list->next;
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/*----------------------------------------------------------------------------
|
||
|
* _PyFloat_{Pack,Unpack}{4,8}. See floatobject.h.
|
||
|
*
|
||
|
* TODO: On platforms that use the standard IEEE-754 single and double
|
||
|
* formats natively, these routines could simply copy the bytes.
|
||
|
*/
|
||
|
int
|
||
|
_PyFloat_Pack4(double x, unsigned char *p, int le)
|
||
|
{
|
||
|
unsigned char sign;
|
||
|
int e;
|
||
|
double f;
|
||
|
unsigned int fbits;
|
||
|
int incr = 1;
|
||
|
|
||
|
if (le) {
|
||
|
p += 3;
|
||
|
incr = -1;
|
||
|
}
|
||
|
|
||
|
if (x < 0) {
|
||
|
sign = 1;
|
||
|
x = -x;
|
||
|
}
|
||
|
else
|
||
|
sign = 0;
|
||
|
|
||
|
f = frexp(x, &e);
|
||
|
|
||
|
/* Normalize f to be in the range [1.0, 2.0) */
|
||
|
if (0.5 <= f && f < 1.0) {
|
||
|
f *= 2.0;
|
||
|
e--;
|
||
|
}
|
||
|
else if (f == 0.0)
|
||
|
e = 0;
|
||
|
else {
|
||
|
PyErr_SetString(PyExc_SystemError,
|
||
|
"frexp() result out of range");
|
||
|
return -1;
|
||
|
}
|
||
|
|
||
|
if (e >= 128)
|
||
|
goto Overflow;
|
||
|
else if (e < -126) {
|
||
|
/* Gradual underflow */
|
||
|
f = ldexp(f, 126 + e);
|
||
|
e = 0;
|
||
|
}
|
||
|
else if (!(e == 0 && f == 0.0)) {
|
||
|
e += 127;
|
||
|
f -= 1.0; /* Get rid of leading 1 */
|
||
|
}
|
||
|
|
||
|
f *= 8388608.0; /* 2**23 */
|
||
|
fbits = (unsigned int)(f + 0.5); /* Round */
|
||
|
assert(fbits <= 8388608);
|
||
|
if (fbits >> 23) {
|
||
|
/* The carry propagated out of a string of 23 1 bits. */
|
||
|
fbits = 0;
|
||
|
++e;
|
||
|
if (e >= 255)
|
||
|
goto Overflow;
|
||
|
}
|
||
|
|
||
|
/* First byte */
|
||
|
*p = (sign << 7) | (e >> 1);
|
||
|
p += incr;
|
||
|
|
||
|
/* Second byte */
|
||
|
*p = (char) (((e & 1) << 7) | (fbits >> 16));
|
||
|
p += incr;
|
||
|
|
||
|
/* Third byte */
|
||
|
*p = (fbits >> 8) & 0xFF;
|
||
|
p += incr;
|
||
|
|
||
|
/* Fourth byte */
|
||
|
*p = fbits & 0xFF;
|
||
|
|
||
|
/* Done */
|
||
|
return 0;
|
||
|
|
||
|
Overflow:
|
||
|
PyErr_SetString(PyExc_OverflowError,
|
||
|
"float too large to pack with f format");
|
||
|
return -1;
|
||
|
}
|
||
|
|
||
|
int
|
||
|
_PyFloat_Pack8(double x, unsigned char *p, int le)
|
||
|
{
|
||
|
unsigned char sign;
|
||
|
int e;
|
||
|
double f;
|
||
|
unsigned int fhi, flo;
|
||
|
int incr = 1;
|
||
|
|
||
|
if (le) {
|
||
|
p += 7;
|
||
|
incr = -1;
|
||
|
}
|
||
|
|
||
|
if (x < 0) {
|
||
|
sign = 1;
|
||
|
x = -x;
|
||
|
}
|
||
|
else
|
||
|
sign = 0;
|
||
|
|
||
|
f = frexp(x, &e);
|
||
|
|
||
|
/* Normalize f to be in the range [1.0, 2.0) */
|
||
|
if (0.5 <= f && f < 1.0) {
|
||
|
f *= 2.0;
|
||
|
e--;
|
||
|
}
|
||
|
else if (f == 0.0)
|
||
|
e = 0;
|
||
|
else {
|
||
|
PyErr_SetString(PyExc_SystemError,
|
||
|
"frexp() result out of range");
|
||
|
return -1;
|
||
|
}
|
||
|
|
||
|
if (e >= 1024)
|
||
|
goto Overflow;
|
||
|
else if (e < -1022) {
|
||
|
/* Gradual underflow */
|
||
|
f = ldexp(f, 1022 + e);
|
||
|
e = 0;
|
||
|
}
|
||
|
else if (!(e == 0 && f == 0.0)) {
|
||
|
e += 1023;
|
||
|
f -= 1.0; /* Get rid of leading 1 */
|
||
|
}
|
||
|
|
||
|
/* fhi receives the high 28 bits; flo the low 24 bits (== 52 bits) */
|
||
|
f *= 268435456.0; /* 2**28 */
|
||
|
fhi = (unsigned int)f; /* Truncate */
|
||
|
assert(fhi < 268435456);
|
||
|
|
||
|
f -= (double)fhi;
|
||
|
f *= 16777216.0; /* 2**24 */
|
||
|
flo = (unsigned int)(f + 0.5); /* Round */
|
||
|
assert(flo <= 16777216);
|
||
|
if (flo >> 24) {
|
||
|
/* The carry propagated out of a string of 24 1 bits. */
|
||
|
flo = 0;
|
||
|
++fhi;
|
||
|
if (fhi >> 28) {
|
||
|
/* And it also progagated out of the next 28 bits. */
|
||
|
fhi = 0;
|
||
|
++e;
|
||
|
if (e >= 2047)
|
||
|
goto Overflow;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* First byte */
|
||
|
*p = (sign << 7) | (e >> 4);
|
||
|
p += incr;
|
||
|
|
||
|
/* Second byte */
|
||
|
*p = (unsigned char) (((e & 0xF) << 4) | (fhi >> 24));
|
||
|
p += incr;
|
||
|
|
||
|
/* Third byte */
|
||
|
*p = (fhi >> 16) & 0xFF;
|
||
|
p += incr;
|
||
|
|
||
|
/* Fourth byte */
|
||
|
*p = (fhi >> 8) & 0xFF;
|
||
|
p += incr;
|
||
|
|
||
|
/* Fifth byte */
|
||
|
*p = fhi & 0xFF;
|
||
|
p += incr;
|
||
|
|
||
|
/* Sixth byte */
|
||
|
*p = (flo >> 16) & 0xFF;
|
||
|
p += incr;
|
||
|
|
||
|
/* Seventh byte */
|
||
|
*p = (flo >> 8) & 0xFF;
|
||
|
p += incr;
|
||
|
|
||
|
/* Eighth byte */
|
||
|
*p = flo & 0xFF;
|
||
|
p += incr;
|
||
|
|
||
|
/* Done */
|
||
|
return 0;
|
||
|
|
||
|
Overflow:
|
||
|
PyErr_SetString(PyExc_OverflowError,
|
||
|
"float too large to pack with d format");
|
||
|
return -1;
|
||
|
}
|
||
|
|
||
|
double
|
||
|
_PyFloat_Unpack4(const unsigned char *p, int le)
|
||
|
{
|
||
|
unsigned char sign;
|
||
|
int e;
|
||
|
unsigned int f;
|
||
|
double x;
|
||
|
int incr = 1;
|
||
|
|
||
|
if (le) {
|
||
|
p += 3;
|
||
|
incr = -1;
|
||
|
}
|
||
|
|
||
|
/* First byte */
|
||
|
sign = (*p >> 7) & 1;
|
||
|
e = (*p & 0x7F) << 1;
|
||
|
p += incr;
|
||
|
|
||
|
/* Second byte */
|
||
|
e |= (*p >> 7) & 1;
|
||
|
f = (*p & 0x7F) << 16;
|
||
|
p += incr;
|
||
|
|
||
|
/* Third byte */
|
||
|
f |= *p << 8;
|
||
|
p += incr;
|
||
|
|
||
|
/* Fourth byte */
|
||
|
f |= *p;
|
||
|
|
||
|
x = (double)f / 8388608.0;
|
||
|
|
||
|
/* XXX This sadly ignores Inf/NaN issues */
|
||
|
if (e == 0)
|
||
|
e = -126;
|
||
|
else {
|
||
|
x += 1.0;
|
||
|
e -= 127;
|
||
|
}
|
||
|
x = ldexp(x, e);
|
||
|
|
||
|
if (sign)
|
||
|
x = -x;
|
||
|
|
||
|
return x;
|
||
|
}
|
||
|
|
||
|
double
|
||
|
_PyFloat_Unpack8(const unsigned char *p, int le)
|
||
|
{
|
||
|
unsigned char sign;
|
||
|
int e;
|
||
|
unsigned int fhi, flo;
|
||
|
double x;
|
||
|
int incr = 1;
|
||
|
|
||
|
if (le) {
|
||
|
p += 7;
|
||
|
incr = -1;
|
||
|
}
|
||
|
|
||
|
/* First byte */
|
||
|
sign = (*p >> 7) & 1;
|
||
|
e = (*p & 0x7F) << 4;
|
||
|
p += incr;
|
||
|
|
||
|
/* Second byte */
|
||
|
e |= (*p >> 4) & 0xF;
|
||
|
fhi = (*p & 0xF) << 24;
|
||
|
p += incr;
|
||
|
|
||
|
/* Third byte */
|
||
|
fhi |= *p << 16;
|
||
|
p += incr;
|
||
|
|
||
|
/* Fourth byte */
|
||
|
fhi |= *p << 8;
|
||
|
p += incr;
|
||
|
|
||
|
/* Fifth byte */
|
||
|
fhi |= *p;
|
||
|
p += incr;
|
||
|
|
||
|
/* Sixth byte */
|
||
|
flo = *p << 16;
|
||
|
p += incr;
|
||
|
|
||
|
/* Seventh byte */
|
||
|
flo |= *p << 8;
|
||
|
p += incr;
|
||
|
|
||
|
/* Eighth byte */
|
||
|
flo |= *p;
|
||
|
|
||
|
x = (double)fhi + (double)flo / 16777216.0; /* 2**24 */
|
||
|
x /= 268435456.0; /* 2**28 */
|
||
|
|
||
|
/* XXX This sadly ignores Inf/NaN */
|
||
|
if (e == 0)
|
||
|
e = -1022;
|
||
|
else {
|
||
|
x += 1.0;
|
||
|
e -= 1023;
|
||
|
}
|
||
|
x = ldexp(x, e);
|
||
|
|
||
|
if (sign)
|
||
|
x = -x;
|
||
|
|
||
|
return x;
|
||
|
}
|