[PyPy-issue] [issue636] 64bit JIT Failure on trunk

Bob Ziuchkovski pypy-dev-issue at codespeak.net
Mon Mar 7 09:02:26 CET 2011

Bob Ziuchkovski <bob.ziuchkovski at gmail.com> added the comment:

I have done a final bit of testing and it seems this error is specifically tied 
to unrolling a loop that contains a floating point variable as input.  
Furthermore, it appears the floating point value of the variable is lost and 
something very close to the 64bit minimum positive double value is used instead.  
The result of the attached floating_point_unroll_error.py is that after 
unrolling with the following arithmetic results occur:

# below, floatvar stores 2.0
1 * floatvar returns 6.92386558364043e-310
1 + floatvar returns 1.0
1 - floatvar returns 1.0

PyPy development tracker <pypy-dev-issue at codespeak.net>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: floating_point_unroll_error.py
Type: text/x-python
Size: 301 bytes
Desc: not available
URL: <http://mail.python.org/pipermail/pypy-issue/attachments/20110307/915e01bf/attachment.py>

More information about the Pypy-issue mailing list