Re: Parsing timestamps?

Paul Rubin <no.email@nospam.invalid> writes:

dxf <dxforth@gmail.com> writes:

As for SSE2 it wouldn't exist if industry didn't consider
double-precision adequate.

>
SSE2 is/was first and foremost a vectorizing extension, and it has been
superseded quite a few times, indicating it was never all that
adequate.

But SSE2 was also the way to finally implement mainstream floating
point: double precision instead of extended precision (with its
double-rounding woes when trying to implement double precision) and
registers (for which register allocation algorithms have been worked
on for a long time) instead of the stack.  So starting with AMD64
(which was guaranteed to include SSE2) SSE2 became the preferred
scalar floating point instruction set, which is also reflected in the
ABIs on AMD64.  And in this function SSE2 has not been superseded.

Concerning vectors, AVX allows 256 bits of width, eliminates the
alignment brain damage of SSE/SSE2, and gives us three-address
instructions.  AVX2 gives us integer instructions.  The various
AVX-512 extensions are a mess of overlapping extensions (to be unified
by AVX10) that generally provide up to 512 bits of width and control
of individual lanes with mask registers.

I don't know whether any of its successors support extended
precision though.

No.

W. Kahan was a big believer in extended precision (that's why the 8087
had it from the start).  I believes IEEE specifies both 80 bit and 128
bit formats in addition to 64 bit.

Not 80-bit format.  binary128 and binary256 are specified.

- anton
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