On Sun, Oct 22, 2000 at 04:08:16PM +1100, Chris Baird wrote:
> While profiling a math-intensive application, I discovered that libm,
> (as built by a 1.4.2 'make release'), uses software rather than
> hardware based math functions, at least with sqrt.
> 
> Digging deeper revealed "i387_LIBM" in mk.conf controls this, and
> recompiling a FPU-savvy math library made an incredible difference in
> FP performance. (My satellite predictor program now runs 3 times
> faster with no differences in output...)
> 
> Is there any reason the port doesn't use this by default?

Yes, because we may run on FPU-less hardware.

> (Particularly with FPUs being IEEE754/854.) At the very least,
> I387_LIBM should be documented somewhere (aside from the 1.3-1.4
> ChangeLog).
> 
> Let me know if this should not be pr'd.

1.5 has a mechanism to choose the rigth library at run-time.

--
Manuel Bouyer <bouyer@antioche.eu.org>
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