diff --git a/Include/cpython/floatobject.h b/Include/cpython/floatobject.h index fffd468690274e..0f8ab31ae62303 100644 --- a/Include/cpython/floatobject.h +++ b/Include/cpython/floatobject.h @@ -10,3 +10,51 @@ typedef struct { // Macro version of PyFloat_AsDouble() trading safety for speed. // It doesn't check if op is a double object. #define PyFloat_AS_DOUBLE(op) (((PyFloatObject *)(op))->ob_fval) + +/* _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); diff --git a/Include/internal/pycore_floatobject.h b/Include/internal/pycore_floatobject.h index 891e422f594721..a099f2ebc0fec6 100644 --- a/Include/internal/pycore_floatobject.h +++ b/Include/internal/pycore_floatobject.h @@ -38,54 +38,6 @@ struct _Py_float_state { #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);