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Subject: Re: [PATCH] bitmap: simplify GENMASK(size - 1, 0) lines
To:     Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Yury Norov <yury.norov@gmail.com>
CC:     Rasmus Villemoes <linux@rasmusvillemoes.dk>,
        <linux-kernel@vger.kernel.org>
References: <20211026144108.35373-1-quic_qiancai@quicinc.com>
 <YXhOEEOSG+fgEy+t@yury-ThinkPad> <YXhVVvG9keoVWJyK@smile.fi.intel.com>
From:   Qian Cai <quic_qiancai@quicinc.com>
Message-ID: <397751ea-536b-af3c-752d-c4b1045e6e56@quicinc.com>
Date:   Tue, 26 Oct 2021 15:33:48 -0400
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On 10/26/21 3:21 PM, Andy Shevchenko wrote:
> Can you explain to me how it is supposed to work?
> 
> For example,
> 
>     x = 0xaa55;
>     size = 5;
> 
>     printf("%lu\n", find_first_bit(&x, size));
> 
> In the resulting code we will always have 5 as the result,
> but is it correct one?

Sorry, my bad. GENMASK(size - 1, 0) would just become __GENMASK(size -
1, 0) instead of 0. Let me revisit it and run some tests first.