Re: Meeting the Scope and Purpose of P754

[David Hough 754R work <754r@xxxxxxxxxxx>]

> And to convert it to engineer hours: one CERN engineer spent IIRC three 
> months parallelizing the code using Boinc, then three more months 
> tracking last-bit differences, finally discovering that AMD and Intel 
> processors didn't have bit-for-bit compatible exp and log functions. 
> These are three months of my taxpayer's money that I hope the upcoming 
> standard will save.

Customers have rejected AMD-based systems 
because they haven't delivered identical
results to Intel-based systems.   They might be convinced that the results are
just as good, but they aren't the same, and nobody enjoys tracking down
these kinds of discrepancies.

And the burden just isn't on AMD; if these customers had their way, Intel
would have to use the same transcendental function algorithms forever, whether
they make sense in future technologies or not.     
It's a lesson to anybody 
planning to put incompletely-defined instructions into an instruction set
intended to last a long time.
Combined with the
strange interactions of compilers and extended precision, no wonder
the escape plan for the future seems to lie in the SSE2 direction 
rather than the x87 extended stack.