Kiriakos Vlahos <pyscrip...@gmail.com> added the comment: I found out that $x2xx (test both $12xx and $02xx) gives identical results to python. Here is what it means.
The PC field (bits 9 and 8) or Precision Control determines to what precision the FPU rounds results after each arithmetic instruction in one of three ways: 00 = 24 bits (REAL4) 01 = Not used 10 = 53 bits (REAL8) <- This is required by _Py_dg_dtoa 11 = 64 bits (REAL10) (this is the initialized state) So contrary to my expectation it is not the rounding control bits but the Precision control bits that matter. ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue9980> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com