bpo-46906: Move _PyFloat_{Pack,Unpack}{4,8} from internal to cpython

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);

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);