| [eigen] (General question) Floating point: why are 'inf' and 'nan' slow? |
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- To: eigen <eigen@xxxxxxxxxxxxxxxxxxx>
- Subject: [eigen] (General question) Floating point: why are 'inf' and 'nan' slow?
- From: Benoit Jacob <jacob.benoit.1@xxxxxxxxx>
- Date: Tue, 22 Sep 2009 20:51:58 -0400
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Hi,
Sorry for adding to the currently already high traffic here.
Here, on linux / x86, my programs run 100x slower when the
floating-point values are 'inf' or 'nan'.
Only scalar code is affected, SSE code is not affected.
I haven't enabled floating-point exception signals. I don't have a FP
signal handler. Just any basic c++ program.
Can this be "fixed"? How?
Otherwise, I really need to make sure that solve() methods avoid
producing such special values when no solution exists --- otherwise
they take much longer to return.
Thanks for your help,
Benoit