Re: Linking Problem


In article <Xns9662B232731C1rws0203comcastnet@xxxxxxxxxxxxxx>, Russell <rws0203nospam@xxxxxxxxxxx> writes:
>
> If you did try to get by with compiling to an INT on one system, and
> running on another, note that INT's are quite slow.

A rule of thumb used by some people who study performance is that on
contemporary general-purpose processors, the worst case for micro-
interpreted code (such as MF COBOL INT code, Java bytecode, UCSD P-
System, etc) is about an order of magnitude performance hit. That
would be for CPU-bound code with a broad instruction spectrum, and
is due largely to cache penalties incurred by having to perform a
table lookup for each byte.

In practice, the actual performance cost for CPU-bound code is
typically significantly smaller (because the instruction spectrum of
typical code is smaller, CPU-bound code is often running in tight
loops that are cache-friendly, interpreted code isn't often used for
processing huge data sets that might stress the data cache, etc).
It's more likely to be a factor of 3-5.

With MF COBOL you have the option of compiling to INT, moving the INT
to your target platform, testing it there, and then compiling it to
native code, of course. This recompile-portable-form-to-native-form
approach is similar to what the OSF was trying to do with ANDF - a
good idea that never really got off the ground. JIT compilation is
flashier, but all-at-once recompilation is a lot more efficient.

--
Michael Wojcik michael.wojcik@xxxxxxxxxxxxxx

Even though there may be some misguided critics of what we're trying
to do, I think we're on the wrong path. -- Reagan
.

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