🚀 go-pugleaf

In article <93452@sun.uucp> garner@sun.UUCP (Robert Garner) writes:
.....
>The judgement so far is that the 22% improvement must be coming from
>the FORTRAN version.  As I've never seen a FORTRAN version of 
>Dhrystone, does anyone at Intel have the source that they could
>post on the net?  Or was the reference to the Fortan
>compiler a typo?  (The Performance brief remarks:
>"Dhrystone was developed in ADA by R. Weicker in 1984.
>Fortran and C versions of the benchmark are more commonly used.")

>It will be interesting to see how pointers and structures are handled.
>Also, which Fortran library routine was used to do the string copies?

If it is indeed true that this is no typo, it is fascinating,
as it is well-known that C's byte-by-byte copy can add 25-30% over
(for example) PASCAL, or anything that has fixed-length character strings.
(On an R3000, 34% of Dhrystone is in strcmp & strcpy.)
Of course it depends on what kind of code-generation is done, also,
i.e., in-line versus out-of-line.

In reading the Intel i860(TM) performacne document, it is interesting
to note that 7 benchmarks are presented:
Dhrystone 1.1 and 2.1, Stanford Integer, SP & DP Whetstone,
and FORTRAN and Coded LINPACK.

Of these, the document claims that Dhrystone was in FORTRAN,
and Stanford and LINPAK were simulated (with zero-wait-state memory;
this makes little difference to Stanford, as it mostly fits in the cache.)

That means, that in terms of published benchmarks that seem apples-to-apples
comparable, the sum total is:  SP & DP Whetstone.

On Feb 27, Green Hills announced it was shipping C and FORTRAN compilers
for the i860, so it does seem a little strange that C wouldn't have been
used.  Maybe it is a typo, and there's some other reason.
-- 
-john mashey	DISCLAIMER: <generic disclaimer, I speak for me only, etc>
UUCP: 	{ames,decwrl,prls,pyramid}!mips!mash  OR  mash@mips.com
DDD:  	408-991-0253 or 408-720-1700, x253
USPS: 	MIPS Computer Systems, 930 E. Arques, Sunnyvale, CA 94086