Re: [PATCH v2] vhost: replace % with & on data path

From: Andy Shevchenko
Date: Sat Dec 12 2015 - 19:01:28 EST


On Fri, Dec 4, 2015 at 10:19 PM, Venkatesh Srinivas
<venkateshs@xxxxxxxxxx> wrote:
> On Mon, Nov 30, 2015 at 11:15:23AM +0200, Michael S. Tsirkin wrote:
>> We know vring num is a power of 2, so use &
>> to mask the high bits.
>>
>> Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
>> ---
>
> The generated code switches from DIV -> masking, source is clearer as well.

First impression was why, now it seems that compiler can't predict
this for variables.
For constants it would be optimized to the same, I suppose.

>
> Tested-by: Venkatesh Srinivas <venkateshs@xxxxxxxxxx>
>
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--
With Best Regards,
Andy Shevchenko
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