Tom Lane wrote:
> Luis Amigo <lamigo@atc.unican.es> writes:
>
> > I believe i've found a reasonable explanation, there is a architecture
> > disroupt between old MIPS3 FPUs
> > and newer MIPS4 FPUs.(so I'm almost sure that is the explanation).
>
> If Pete's lost interest then I'd be willing to adopt your results as
> the standard geometry-irix file. If he's still interested then we'd
> need to figure out a way for the resultmap mechanism to distinguish
> older and newer MIPS hardware in order to accommodate two sets of
> IRIX geometry results. Got any idea how to do that? (Does config.guess
> produce any relevant info?)
>
> regards, tom lane
First I have to apologize, I said MIPS3 and MIPS4 architecture, MIPS are
proccesor instructions set no architecture, and r8000 CPUs have MIPS4
instructions set.
I should have said old 8010 FPUs and newer 10010 and 12010 FPUs.
I think there are only three possible reasons in differences:
1.- FPUs architecture.
2.- compiler specific optimization( It's only possible if Pete turned on
extensive optimization for 8000), because we are compiling with
full-compatibility options -rx directives optimize cache and memory use but
does not affect proccessors.)
3.-If regress is sending binary data to disk and later retrieving the data
and writing output files, there "might" be rounding up differences between
what was written and readed.
I still believe this difference is made by FPUs
config.guess only says mips-sgi-irix6.5
I think we can make two results choosing FPUs from hinv
but we don´t have another r8000 to test Pete's results nor another r10000 or
12000 to test our results.
I would try to test in our 4 r10000 IP27 to be sure that our results are
right.
regards Luis Amigo