3 Nov
2005
3 Nov
'05
10:15 p.m.
der Mouse wrote:
Apparently, yes :-)
Certainly. But you can't learn about the three
that are wanted by a
nontrivial fraction of the userbase without listening to them all.
This was Intel, so even the NSA/CIA/FBI/EFF all put together are
not going to amount to anything more than noise compared to the
number of CPUs that Microsoft can help ship. Adding features to
something as crufty as ix86 (much of the talk seemed to be about
bending over backwards - while blindfolded - to try and keep up
some semblance of backwards compatibility) has a dollar, time
(to market) and performance cost. Saving the world comes a
distant second to keeping ahead of AMD!
Other things not to ask for: "Can we have instruction X,
and keep it secret: it'll be our competitive advantage"
Seriously, if
you need pop(N) or whatever, you can implement it today
and in a year (or two) from now you'll be running as fast as you
thought you would have been with pop(N).
And you have the nerve to preface that with "seriously"?! You could say the same about pretty much any
software thing
- simulate it and let Moore's Law speed it up. Some of us aren't
willing to wait a year (or two) per feature to run it at a decent
speed.
You aren't willing to pay the costs of having your pet instructions
added to ix86 either, I'll wager!
Actually I think the speaker's point was mostly that
adding instruction X almost never lead to the supposed performance
benefits, especially given the complex pipelined nature of
the processor. To say nothing of the work required to get
the instruction properly supported (and optimised
etc.) by the required compiler(s).
I presume that the guy knew what he was talking about as he'd
managed to get P3 (or P4, whatever) out the door and managed
his processor managed to survive in a world where RISC was
supposed to be performance king. Most importantly of all, he'd
managed to avoid being mired in the Itanium fiasco, so I
was willing to cut him a fair amount of slack.
Antonio
--
Antonio carlini
arcarlini at iee.org