On Thu, 2006-07-20 at 04:19 +1000, Paul Mackerras wrote:

Linas Vepstas writes:

quoted

But perhaps, in principle, couldn't one run four independent streams 
in parallel?  Thus, for example, on an SSL-enabled web server, one 
could service multiple encryption/decryption threads at once. 

Generally that would work.  If one had 4 separate streams to compute a
SHA1 of, one could do all 4 at once with altivec.  It would have to be
4 separate streams though, not 4 parts of a single stream.

I'd think it'd be pretty hard to get a real benefit from this because
the data is going to come from 4 totally different places, hence you
can't just load a single vector register and get data for all 4
streams...

johannes