[PATCH] Speedup tanf range reduction

[Wilco Dijkstra]

Adhemerval Zanella wrote:

> tanf seems to be the only place where __ieee754_rem_pio2f is used, so we
> can remove sysdeps/ieee754/flt-32/e_rem_pio2f.c and
> sysdeps/powerpc/fpu/e_rem_pio2f.c.  Also, I would like to certify that
> it is faster than powerpc version (I would expect so, but at least it
> would be good to actually get some numbers).

Yes, I'm removing those and some more unused math files in my next patch.

The __ieee754_rem_pio2f for powerpc is not substantially different from the generic
version, so the performance gains will be similar. Note TOINT_INTRINSICS could
be enabled for even faster range reduction on any target that supports round() as a
single instruction.

Wilco