Re: [PATCH] bitops: simplify get_count_order_long()

From: Wei Yang
Date: Thu May 28 2020 - 18:18:39 EST


On Wed, May 27, 2020 at 04:05:08PM -0700, Andrew Morton wrote:
>On Wed, 27 May 2020 22:45:42 +0000 Wei Yang <richard.weiyang@xxxxxxxxx> wrote:
>
>> /* a tiny module only meant to test get_count_order/long */
>> unsigned int order_comb[][2] = {
>> {0x00000003, 2},
>> {0x00000004, 2},
>> {0x00001fff, 13},
>> {0x00002000, 13},
>> {0x50000000, 32},
>> {0x80000000, 32},
>> };
>>
>> static int __init test_getorder_startup(void)
>> {
>> int i;
>>
>> for (i = 0; i < ARRAY_SIZE(order_comb); i++) {
>> if (order_comb[i][1] != get_count_order(order_comb[i][0]))
>> pr_warn("get_count_order wrong for %lx\n",
>> order_comb[i][0]);
>> }
>>
>> return 0;
>> }
>>
>> Since I don't get a way to iterate all the possibilities, some random
>> combination is chosen. Is this one looks good?
>
>Looks good.
>
>You might want to add a less-negative number as well? 0x80030000.
>Something that won't turn positive if it has 1 subtracted from it.

Thanks, this is a good suggestion.

--
Wei Yang
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