Re: RISC

[Ted Dennison<dennison@telepath.com>]

In article <99ae0k$g0j$1@nh.pace.co.uk>, Marin David Condic says...
>
>Very true. This is why lots of mission critical systems *freeze* a version
>of the compiler at some juncture in the project. Better the bugs you know
>than to have something totally unexpected show up in a new release.

But that isn't even sufficient to keep you safe from erronious code. Assuming
that the generated code might be affected by how the compiler decides to
optimize (a quite reasonable assumption), then your code could cease to work if
any of the following happen:

o  You recompile with a different set of options.
o  You change a line of code somewhere in the entire system and recompile.

and in some cases (notably the old DEC Ada compiler)...
o  You compile on a different machine.
o  You compile on the same machine, but with a different amount of free RAM
(different set of background processes running at the time).

You really should not *ever* use erronious code unless you have some kind of
good assurance from your vendor that it will behave predictably (often the
vendor docs will mention some such instances). I suppose having access to the
sources of your compiler and checking it over yourself might count, but that
would probably be more work than finding a better way.

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