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Re: Interaction between rounding direction and trigonometricfunctions
On Fri, 2008-09-05 at 13:43 -0500, Ryan Arnold wrote:
> Did you address some issues in the GLIBC bugzilla regarding rounding direction?
The issue I looked at was for printf checking rounding mode:
http://sources.redhat.com/bugzilla/show_bug.cgi?id=5044
This issue with cos appears to be unrelated. I didn't find any bugs on
http://sources.redhat.com/bugzilla/ searching for "round cos". This
looks like a candidate for a new bug.
Also, here are the results for SLES10 SP1, Power6, using Advance
Toolchain GLIBC 2.8, GCC 4.3.1, again very wrong:
theta = 5.27906
sin(theta) = -0.843695
cos(theta) = 0.536822
Repeating after setting the rounding direction to UPWARD:
theta = 5.27906
sin(theta) = -0.0702948
cos(theta) = 9.55255
--
Pete Eberlein
IBM Linux Technology Center
Linux for Power Toolchain