Re: results: Remove 8 bytes from struct page on 64bit archs

[Anton Blanchard]

> The powerpc backend claims to have a fast divide instruction
> (via RTX_COST if you care about such things).  We'll replace
> with shift when dividing by powers of 2, but won't try the
> multiply by a constant inverse trick.

To follow up: Alan Modra found and fixed the bug, it seems we were only
using the optimisation when the arguments were <= 32bit.

The target we use is RS64a which has a cost of 60 odd instructions
for divide.

Anton