[Beowulf] A start in Parallel Programming?

Jim Lux James.P.Lux at jpl.nasa.gov
Tue Mar 13 20:56:14 PDT 2007


At 05:30 PM 3/13/2007, Robert G. Brown wrote:
>On Tue, 13 Mar 2007, Jim Lux wrote:
>
>>Now that I think about it, I actually quite liked working in PL/I.
>
>Me too.
>
>>it's easy to write without GOTOs in FORTRAN...
>>
>>        IF (0) 902,902,902
>>
>>is the same as
>>        GOTO 902
>
>Again, I'm left speechless.  I wonder if I would have gotten credit on
>all my assignments where they took off points for goto spaghetti...


I should mention that if you want to really obfuscate things, you 
could do something like

         IF (0) 901,902,903

because  you know that only 902 will be a target.  And, almost all 
compilers could figure out that the argument is fixed, so it would 
emit a JMP $902 or whatever...  You could make the other targets 
something really obscure, and hopefully many pages away, and rather 
than make the argument a constant, some complex expression that 
always evaluates to the same value (like those "think of a number" puzzles).

Good for detecting copyright infringments, eh?


James Lux, P.E.
Spacecraft Radio Frequency Subsystems Group
Flight Communications Systems Section
Jet Propulsion Laboratory, Mail Stop 161-213
4800 Oak Grove Drive
Pasadena CA 91109
tel: (818)354-2075
fax: (818)393-6875 





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