Improvements to powerpc32 asm code

[Mark Rodenkirch]

Thanks.  In my addmul_1.asm, the loop I have only handles one limb per 
iteration, which makes the code much easier to follow than the current 
implementation.  I attempted both two and four limbs per iteration, but 
I saw no gain from that.

I thought that GMP strongly avoided fp instructions in the integer code 
because of rounding errors or does that only apply to FFT multiply?

I have only found one resource on the net that discusses cycles and 
latency of powerpc assembler instructions and it doesn't include the G3 
or G4.  What do you use as a resource?

In future versions of GMP will there be subfolders in powerpc32 to 
allow for different versions dependent upon which flavor of CPU one has?

--Mark