linux-kernel - Re: [PATCH] bitops: simplify get_count_order

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Message-ID: <20200525144312.mbw2z3ydncyasvss@master>
Date:   Mon, 25 May 2020 14:43:12 +0000
From:   Wei Yang <richard.weiyang@...il.com>
To:     Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Cc:     Wei Yang <richard.weiyang@...il.com>, akpm@...ux-foundation.org,
        christian.brauner@...ntu.com, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] bitops: simplify get_count_order_long()

On Mon, May 25, 2020 at 12:14:58PM +0300, Andy Shevchenko wrote:
>On Sun, May 24, 2020 at 12:35:51PM +0000, Wei Yang wrote:
>> These two cases could be unified into one.
>
>Care to provide a test case which supports your change?
>

Hmm.. where should I put the test? tools/testing/selftests/ ?

>> Signed-off-by: Wei Yang <richard.weiyang@...il.com>
>> ---
>>  include/linux/bitops.h | 5 +----
>>  1 file changed, 1 insertion(+), 4 deletions(-)
>> 
>> diff --git a/include/linux/bitops.h b/include/linux/bitops.h
>> index 9acf654f0b19..5b5609e81a84 100644
>> --- a/include/linux/bitops.h
>> +++ b/include/linux/bitops.h
>> @@ -206,10 +206,7 @@ static inline int get_count_order_long(unsigned long l)
>>  {
>>  	if (l == 0UL)
>>  		return -1;
>> -	else if (l & (l - 1UL))
>> -		return (int)fls_long(l);
>> -	else
>> -		return (int)fls_long(l) - 1;
>> +	return (int)fls_long(--l);
>>  }
>
>-- 
>With Best Regards,
>Andy Shevchenko
>

-- 
Wei Yang
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