[PATCH][ppc] merge in powerpc version of slowpow.c

[Siddhesh Poyarekar]

On Thu, Jan 03, 2013 at 12:14:09PM +0100, Andreas Jaeger wrote:
> >/* Compute pow as long double, which is 106 bits precision for IBM
> >    long double and 112 bits for IEE754 long double format.  */
> 
> x86-64 uses the code as well and has 80-bit precision.
> 

Oh, then I think my patch would be wrong for x86 - I was considering
only the ibm and ieee long double types and missed the fact that
x86-64 long double is just 80 bits.  The constant 0x4.0-p96 will be
useless since 0x1.0 + 0x4.0-p96 will get truncated to 0x1.0, rendering
the last accuracy check useless.

Siddhesh