On Mon, Jan 26, 2015 at 3:12 PM, Andrew Gierth
<andrew@tao11.riddles.org.uk> wrote:
> Obvious overheads in float8 comparison include having to check for NaN,
> and the fact that DatumGetFloat8 on 64bit doesn't get inlined and forces
> a store/load to memory rather than just using a register. Looking at
> those might be more beneficial than messing with abbreviations.
Aren't there issues with the alignment of double precision floating
point numbers on x86, too? Maybe my information there is at least
partially obsolete. But it seems we'd have to control for this to be
sure.
I am not seriously suggesting pursuing abbreviation for float8 in the
near term - numeric is clearly what we should concentrate on. It's
interesting that abbreviation of float8 could potentially make sense,
though.
--
Peter Geoghegan