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    SubjectRe: 2.4.0-test10-pre6: Use of abs()
    On Mon, Oct 30, 2000 at 03:01:16PM +0100, Martin Dalecki wrote:
    > Horst von Brand wrote:
    > >
    > > Red Hat 7.0, i686, gcc-20001027 (Yes, I know. Just to flush out bugs on
    > > both sides).
    > >
    > > abs() is used at least in:
    > >
    > > arch/i386/kernel/time.c
    > > drivers/md/raid1.c
    > > drivers/sound/sb_ess.c
    > >
    > > gcc warns about use of a non-declared function each time.
    > >
    > > No definition for the function is to be found (grep over all include/ comes
    > > up clean, except for extern definitions in asm-{mips,ppc}; ditto for lib/).
    > > Presumably gcc is using a builtin (it doesn't show up in System.map). Is
    > > this the desired state of affairs? Should a include/linux/stdlib.h be
    >
    > Yes abs will be transformed into an internal function, which will be
    > fully
    > unrolled due to -O2.

    No matter what it should be prototyped in some header. And all uses should
    be checked, because abs is
    int abs (int) __attribute__ ((__const__));
    and sometimes people use it on `long' instead (such a bug has been fixed in
    the kernel some months ago).

    Jakub
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