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    SubjectRe: egcs-1.1.2 ping bug also causes miscompilation of pcbit isdn drive
    > It just so happens that the kernel is _the_ code that most streches the
    > compiler, AFAIK. Breakage due to ill-understood features, usage of outright
    > compiler bugs and reliance on optimizations done a certain way (or not
    > done) does happen.

    There are two aspects to this. Firstly egcs inevitably causes some code
    breakage as it changes, sometimes bugs, often things like uninitialised
    variables that in gcc generated code happened to start at zero. And now
    alias analysis, which can be a real PITA, but look at the code output with and
    without and it says it all.

    The second is having ways to say "don't do any alias analysis on this
    variable", which egcs does not as far as I can see have an ideal way to handle
    (volatile is not the answer, volatile is one of the more broken bits of C
    design. C needs ways to declare points for synchronziation not say 'this
    variable is always to cause crap code generation') egcs has asm clobber
    stuff which can do memory synchronization. It also has some hacks with
    union to stop aliasing going too far astray , so the tools exist even if they
    aren't what we like.

    > overwhelming mayority of the time. The egcs team is doing exactly the same,
    > to them the kernel is just _one_ more client among many thousands. An
    > important one, but in no way in a position to dictate egcs policy. And that
    > is also fine with me.
    > You'll have to live with that.

    The egcs team needs to deliver tools that can be used to compile the kernel.
    If they produce a compiler that can't be gently told what to do then the
    egcs project will split or have a permanent set of linux specific patches.

    Right now the egcs compiler _can_ be used to build the kernel, and you can
    if you want to contribute go through the source and 2.95 output and fix the
    aliasing problems. Egcs does provide the relevant control needed. Your patches
    will be to the kernel not egcs.

    > Fine. Let others do the grunt work (Alan Cox was instrumental in getting
    > linux to compile with egcs; I did my bit too, there were/are many others)

    I did nothing with egcs fixing but collect patches from the people who did fix
    the kernel code. The credit belongs elsewhere.


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