🚀 go-pugleaf

In article <1991May4.161834.4487@vax5.cit.cornell.edu> umh@vax5.cit.cornell.edu writes:
>RAM than try to get a completely 25MHz R3000 system. Also, I suspect MIPs at 
>least are going to push for full 64 bits from the start, to avoid a hassle 
>a few years from now. Is John Mashey in a postion to confirm this?

(last post for a few weeks): the R4000 is a 64-bit chip right now,
although testing can always be counted on to find bugs sooner or later.
It will take a while to get all of the software together; among other
things, we are talking seriously with certain other vendors who have a
strong interest in 64-bit C models, to make sure that inconsistencies
are at least reasoned, rather than accidental.
We didn't go to the trouble of doing this not to use it.... :-)

There will a be a 64-bit article in Byte a few months off that talks about
64-bit, especially why people might want it [not just the addressing
uses discussed here before, but the integer performance speedup for
some kinds of programs.  Note that all of the data so far says
that it's pretty hard to get much more than .8 SPECint/MHz,
and if 64-bit integers helped you get more, that would help.
People are doing aterrific job of boosting SPECfp/MHz;
SPECint and equivalent integer codes are proving more recalcitrant.
Don't expect 2X, but some uses are:
	cryptography folks like 64-bit mul/div.
	optimizing compilers do a lot of work on bit vectors.
	bitblt folks of course love 64-bit ints.
	Also, there's the humorous use of actually being able to
	represent financial quantities as integers: observe that
	even $/cents-denominated values are often too large for
	32-bit ints [Yen is about the same as cents, Lira or Won
	make it worse :-)]
-- 
-john mashey	DISCLAIMER: <generic disclaimer, I speak for me only, etc>
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