...
> The fact is, the original alpha is the worst architecture ever made.
> The lack of byte instructions and the absolutely horrendous memory
> ordering are fatal flaws. And while the memory ordering arguably had
> excuses for it ("they didn't know better"), the lack of byte ops was
> wilful misdesign that the designers were proud of, and made a central
> tenet of their mess.
If it wasn't from DEC (where the pdp-11 and vax were fine) I'd think
it was someone harking back to the old mainframe days where is was
perfectly normal to only have 'word addressing' and, for example,
to put three 6-bit characters into an 18-bit word (hi Univac!).
(Don't even think how 18-bit words got written to mag tape!)
It is almost as is someone assumed that the only use for byte accesses
was within character arrays - and they can jolly well align the arrays.
Mind you, all the byte shifting needed to get the data onto the
right data bus lines is a PITA and will affect the max cpu frequency [1].
So perhaps they decided it was a 'software problem' so some benchmarks
could run faster.
David
[1] I've been busy re-implementing the Nios-II cpu.
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