SH optimized software floating point routines

[Joern Rennecke]

Quoting Kaz Kojima <kkojima@rr.iij4u.or.jp>:

> sh_softfp.patch looks basically OK to me, though I'm curious
> with numbers for fp-bit.c/softfp/softfloat.  Could you show us
> some real speed&size numbers?

I don't have any sh[1234] hardware to EEMBC tests on, but the runtime
difference of 'make check' on i686-pc-linux-gnu X sh-elf using a core2 quad
for fp-bit vs. softfloat (w/ compare/conversion/divsf) is two hours 4 minutes
versus 38 minutes.