This is my patch: [ 1181301 ] make float packing copy bytes when they can which hasn't been reviewed, despite numerous threats to check it in anyway if noone reviews it. Please read the diff on the checkin list, at least! The basic idea is to examine the bytes of some 'probe values' to see if the current platform is a IEEE 754-ish platform, and if so _PyFloat_{Pack,Unpack}{4,8} just copy bytes around. The rest is hair for testing, and tests.

--- a/Python/pythonrun.c	Fri May 27 14:58:06 2005 +0000
+++ b/Python/pythonrun.c	Fri May 27 15:23:20 2005 +0000
@@ -172,6 +172,8 @@
 	if (!_PyInt_Init())
 		Py_FatalError("Py_Initialize: can't init ints");
 
+	_PyFloat_Init();
+
 	interp->modules = PyDict_New();
 	if (interp->modules == NULL)
 		Py_FatalError("Py_Initialize: can't make modules dictionary");