[vorbis-dev] alloca() problem with CodeWarrior

[Segher Boessenkool]

> I agree with brian, if something didn't work on one pc out of a
> thousand, I would try and work around it,

Ah, like this:

-- the user might want to use gcc-2.95 on x86 with an OS distro that
   thinks all the world is an intel pentium pro/2/iii
   ==>  no fp comparisons, again.

-- the user might want to use gcc-2.91.66 on x86
   ==>  we can't reliably use fp comparisons.

-- the user might want to use gcc-3.0.2 on ppc
   ==>  we can't use floating point comparisons to 0.f

-- the user might want to use MSVC older than, erm, 5 I think
   ==>  we can't reliably use floats in static initializers.

-- the user might want to use some older CW version
   ==>  we must make sure all our structs and stack parameter frames
        are 16-byte aligned, in case the user has enabled some goofy
        compiler options and expects the resulting lib to play nice
        with other libs.

Just some of the compiler bugs I noticed while hacking Vorbis (well, #2
wasn't discovered by me, and #5 was a well-known bug already.  And there
already was a compiler fix for it).

All of these happen more than 1 in 1000 users, and none of these can
be worked around without huge sacrifices in either code speed or
legibility or maintainability or whatever.

<p>Yes, we don't use C99 features, because not every compiler has it.
But we won't go as far as writing everything K&R compatible.
Whether or not to use alloca() is somewhere inbetween.

<p>Segher

<p>--- >8 ----
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