Re: [9fans] brucee's 8c on sources?

[Bruce Ellis <brucee@chunder.com>]

see http://www.chunder.com/plan9/ for some details.

basically any expression that involves vlongs, when
compiled using the default library vlong stuff, does
it's fair share of moving data on and off the stack
and calling generic functions.  a complex vlong expr
can produce pages of code.  the new 8c generates
native instructions and uses registers for most ops.
another good speedup is a simple vlong assignment,
which used to be MOVL; CLD; REP; MOVSL; and is now
MOVL; MOVL - the former suffers from many cycles of
setup.  it is probably worth extending this to copies
of larger structures but the tradeoff depends on the
flavour of x86.

why fossil?  well it is very vlongy.

brucee

Russ Cox wrote:

>>given the speed improvements fossil exhibits when compiled with the
>>new 8c i'd very much like to recompile my kernels with it :).
>
> Really?  How much improved?  What's improved?  Latency?
> It surprises me that 64-bit computation was a bottleneck,
> even in fossil.