bcase@amdcad.UUCP (Brian case) (01/24/86)
Ok, guys, here it is: the first "benchmark" of the NEW, improved,
whiter, brighter, IBM PC/RT. This is the guy with the ROMP RISC
processor in it. We saw one at the IBM Palo Alto Engineering
Support Center. It seems ok, but I personally hate system V UNIX.
We ran the famous while loop benchmark:
main ()
{
register int i;
for (i = 0; i < 1000000; ++i)
;
}
Now, the compiler invoked by the cc comand, even with the -O
option, produced the most awful code I have ever seen. So,we
edited the .s file and made the loop only 3 instructions:
L.15:
c 5,0
bltx L.15
sis 5,1
(Note the use of the delayed branch.) I can't quite remember if the
increment was called sis or six, but whatever. The compiler -O
produced a 6 instruction sequence with two branches, etc. Yeech.
Well, the hand-optimized version runs in 1.5 secs (user). On a
Vax 780, the cc -O version (compiles to one instruction) runs in
1.9 secs. The RT cc -O (i.e., without hand-optimization) version
ran in 1.8 secs. So, the RT looks to be indeed faster than a 780,
but by just how much we will not know until definative benchmarks
(like drystone (:-) are run. Looks like a good box for the price.
We saw the low-res screen, but it was interlaced and had a very
good appearance. We saw an automatic demo of a Mac-like editor
and the fonts and windows were very user-inviting. I didn't like
the fact that IBM chose not to go with the tactile-feedback-type
of keyboard that they are famous for (IBM 3101, PC, 3270, etc).
We also tried another experiment: we forked off 11 infinite loop
processes and then tried some vi and ps. The machine still seemed
to have reasonable response to vi commands like 'j'. They also
had a 5080 graphics substation on display, but not connected to
the RT. It is nice, I guess, but is HUGE compared to the RT. I
tend to think that using an AT color graphics card and a small
monitor may be the way to go (unless the 5080 can turn somersaults
or something).
Does anyone know if the C compiler we used was indeed the one
written for the RT by Tartan Labs???
bcase
johnl@BRL.ARPA (01/25/86)
/* Written 9:19 pm Jan 23, 1986 by bcase@amdcad in ima:net.micro */ > Does anyone know if the C compiler we used was indeed the one > written for the RT by Tartan Labs??? See my followup in net.arch. John Levine, Compiler author