mirabilos added the comment: Stefan Krah dixit:
>> fixing this in general would allow keeping the FPUCW on i387 unchanged too. > >Actually dtoa.c (which is used on i387) explicitly requires to change >the control word. Right. By fixing the “older” code, i386 is not required to change the FPUCW any more and can use it too. The problem with changing the FPUCW on i387 is that it changes from 64/15 bit mantissa/exponent to 53/15 bit which is still not the 53/11 bit of IEEE double, so you *still* get double- rounding issues (with denormal numbers only, I guess) because the internal precision is still higher. And on m68k we simply cannot afford to change the FPUCW because that will cause runtime failures on some implementations. >Looking at the test results, it seems to me that a couple of tests >could be skipped if PY_NO_SHORT_FLOAT_REPR is defined, i.e.the >failures are fully expected. Ah okay. >Not sure about the lgamma etc. failures though, perhaps that's >an emulator bug. If I can get self-contained test cases (preferably in C because that makes it easier for others to test), I can ask people who run real bare-metal Atari or Amiga to test them. Or you can ask on debian-...@lists.debian.org for testers. I guess a python2.6 runnable testcase would be okay, even for those running an a bit older “base system”. (I admit mine is not really up to date either, just the build chroots, because of the post-release unfreeze upload peak and related transitions.) bye, //mirabilos -- “It is inappropriate to require that a time represented as seconds since the Epoch precisely represent the number of seconds between the referenced time and the Epoch.” -- IEEE Std 1003.1b-1993 (POSIX) Section B.2.2.2 ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue18062> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com