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    SubjectRe: [PATCH 04/14] lib: introduce BITS_{FIRST,LAST} macro
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    On 18/02/2021 05.05, Yury Norov wrote:
    > BITMAP_{LAST,FIRST}_WORD_MASK() in linux/bitmap.h duplicates the
    > functionality of GENMASK(). The scope of there macros is wider
    > than just bitmap. This patch defines 4 new macros: BITS_FIRST(),
    > BITS_LAST(), BITS_FIRST_MASK() and BITS_LAST_MASK() in linux/bits.h
    > on top of GENMASK() and replaces BITMAP_{LAST,FIRST}_WORD_MASK()
    > to avoid duplication and increase the scope of the macros.
    >

    Please include some info on changes in generated code, if any. When the
    parameter to the macro is a constant I'm sure it all folds to a
    compile-time constant either way, but when it's not, I'm not sure gcc
    can do the same optimizations when the expressions become more complicated.

    Rasmus

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