mirror of https://github.com/python/cpython
106 lines
3.7 KiB
C
106 lines
3.7 KiB
C
#ifndef Py_INTERNAL_FLOATOBJECT_H
|
|
#define Py_INTERNAL_FLOATOBJECT_H
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
|
|
#ifndef Py_BUILD_CORE
|
|
# error "this header requires Py_BUILD_CORE define"
|
|
#endif
|
|
|
|
|
|
/* runtime lifecycle */
|
|
|
|
extern void _PyFloat_InitState(PyInterpreterState *);
|
|
extern PyStatus _PyFloat_InitTypes(PyInterpreterState *);
|
|
extern void _PyFloat_Fini(PyInterpreterState *);
|
|
extern void _PyFloat_FiniType(PyInterpreterState *);
|
|
|
|
|
|
/* other API */
|
|
|
|
#ifndef WITH_FREELISTS
|
|
// without freelists
|
|
# define PyFloat_MAXFREELIST 0
|
|
#endif
|
|
|
|
#ifndef PyFloat_MAXFREELIST
|
|
# define PyFloat_MAXFREELIST 100
|
|
#endif
|
|
|
|
struct _Py_float_state {
|
|
#if PyFloat_MAXFREELIST > 0
|
|
/* Special free list
|
|
free_list is a singly-linked list of available PyFloatObjects,
|
|
linked via abuse of their ob_type members. */
|
|
int numfree;
|
|
PyFloatObject *free_list;
|
|
#endif
|
|
};
|
|
|
|
/* _PyFloat_{Pack,Unpack}{4,8}
|
|
*
|
|
* The struct and pickle (at least) modules need an efficient platform-
|
|
* independent way to store floating-point values as byte strings.
|
|
* The Pack routines produce a string from a C double, and the Unpack
|
|
* routines produce a C double from such a string. The suffix (4 or 8)
|
|
* specifies the number of bytes in the string.
|
|
*
|
|
* On platforms that appear to use (see _PyFloat_Init()) IEEE-754 formats
|
|
* these functions work by copying bits. On other platforms, the formats the
|
|
* 4- byte format is identical to the IEEE-754 single precision format, and
|
|
* the 8-byte format to the IEEE-754 double precision format, although the
|
|
* packing of INFs and NaNs (if such things exist on the platform) isn't
|
|
* handled correctly, and attempting to unpack a string containing an IEEE
|
|
* INF or NaN will raise an exception.
|
|
*
|
|
* On non-IEEE platforms with more precision, or larger dynamic range, than
|
|
* 754 supports, not all values can be packed; on non-IEEE platforms with less
|
|
* precision, or smaller dynamic range, not all values can be unpacked. What
|
|
* happens in such cases is partly accidental (alas).
|
|
*/
|
|
|
|
/* The pack routines write 2, 4 or 8 bytes, starting at p. le is a bool
|
|
* argument, true if you want the string in little-endian format (exponent
|
|
* last, at p+1, p+3 or p+7), false if you want big-endian format (exponent
|
|
* first, at p).
|
|
* Return value: 0 if all is OK, -1 if error (and an exception is
|
|
* set, most likely OverflowError).
|
|
* There are two problems on non-IEEE platforms:
|
|
* 1): What this does is undefined if x is a NaN or infinity.
|
|
* 2): -0.0 and +0.0 produce the same string.
|
|
*/
|
|
PyAPI_FUNC(int) _PyFloat_Pack2(double x, unsigned char *p, int le);
|
|
PyAPI_FUNC(int) _PyFloat_Pack4(double x, unsigned char *p, int le);
|
|
PyAPI_FUNC(int) _PyFloat_Pack8(double x, unsigned char *p, int le);
|
|
|
|
/* The unpack routines read 2, 4 or 8 bytes, starting at p. le is a bool
|
|
* argument, true if the string is in little-endian format (exponent
|
|
* last, at p+1, p+3 or p+7), false if big-endian (exponent first, at p).
|
|
* Return value: The unpacked double. On error, this is -1.0 and
|
|
* PyErr_Occurred() is true (and an exception is set, most likely
|
|
* OverflowError). Note that on a non-IEEE platform this will refuse
|
|
* to unpack a string that represents a NaN or infinity.
|
|
*/
|
|
PyAPI_FUNC(double) _PyFloat_Unpack2(const unsigned char *p, int le);
|
|
PyAPI_FUNC(double) _PyFloat_Unpack4(const unsigned char *p, int le);
|
|
PyAPI_FUNC(double) _PyFloat_Unpack8(const unsigned char *p, int le);
|
|
|
|
|
|
PyAPI_FUNC(void) _PyFloat_DebugMallocStats(FILE* out);
|
|
|
|
|
|
/* Format the object based on the format_spec, as defined in PEP 3101
|
|
(Advanced String Formatting). */
|
|
PyAPI_FUNC(int) _PyFloat_FormatAdvancedWriter(
|
|
_PyUnicodeWriter *writer,
|
|
PyObject *obj,
|
|
PyObject *format_spec,
|
|
Py_ssize_t start,
|
|
Py_ssize_t end);
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
#endif /* !Py_INTERNAL_FLOATOBJECT_H */
|