Re: [PATCH] ext4: simplify 32bit calculation of lblk

[chi wu]

Christoph Hellwig <hch@xxxxxxxxxxxxx> 于2023年4月5日周三 13:40写道：
>
> On Mon, Apr 03, 2023 at 09:53:04PM +0800, wuchi wrote:
> > -                     if (block > ext_block)
> > -                             return ext_pblk + (block - ext_block);
> > -                     else
> > -                             return ext_pblk - (ext_block - block);
> > +                     return ext_pblk + ((signed long long)block - (signed long long)ext_block);
>
> And what exactly is the value add here, except for turning an easy
> to parse statement into a complex expression using casts?
>
Yes，it will be more complex. the original intention is to reduce the
conditional branch.

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