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    SubjectRe: [PATCH v2] scripts: coccinelle: check for !(un)?likely usage
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    Hi,

    On 06.09.2019 23:19, Julia Lawall wrote:
    >
    >
    > On Thu, 29 Aug 2019, Denis Efremov wrote:
    >
    >> This patch adds coccinelle script for detecting !likely and
    >> !unlikely usage. These notations are confusing. It's better
    >> to replace !likely(x) with unlikely(!x) and !unlikely(x) with
    >> likely(!x) for readability.
    >>
    >> The rule transforms !likely(x) to unlikely(!x) based on this logic:
    >> !likely(x) iff
    >> !__builtin_expect(!!(x), 1) iff
    >> __builtin_expect(!!!(x), 0) iff
    >> unlikely(!x)
    >>
    >> For !unlikely(x) to likely(!x):
    >> !unlikely(x) iff
    >> !__builtin_expect(!!(x), 0) iff
    >> __builtin_expect(!!!(x), 1) iff
    >> likely(!x)
    >>
    >> Signed-off-by: Denis Efremov <efremov@linux.com>
    >> Cc: Julia Lawall <Julia.Lawall@lip6.fr>
    >> Cc: Gilles Muller <Gilles.Muller@lip6.fr>
    >> Cc: Nicolas Palix <nicolas.palix@imag.fr>
    >> Cc: Michal Marek <michal.lkml@markovi.net>
    >> Cc: Markus Elfring <Markus.Elfring@web.de>
    >> Cc: Joe Perches <joe@perches.com>
    >> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
    >
    > Acked-by: Julia Lawall <julia.lawall@lip6.fr>
    >
    > A small improvement though would be to improve the explicit dependency of
    > the last four python rules on r1 and r2. Those rules won't execute unless
    > the inherited metavariable has a value, which makes the same dependency.
    >
    > julia

    I think I will resend this patch as a part of patchset with all warnings fixed
    in a couple of days. Hope this will help to create a discussion point with other
    developers about readability of "!likely" and "!unlikely".

    Thanks,
    Denis

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