[PATCH 14/18] xfixes: switch to byte counting functions

Fri Jul 10 04:10:27 PDT 2009

On Fri, Jul 10, 2009 at 11:33:59AM +0100, Bill Crawford wrote:
> Peter Hutterer wrote:
>>> - nbytesRound = (nbytes + 3) & ~3;
>> + nbytesRound = pad_to_dwords(nbytes);
>> You're replacing two arithmetic operations with a function call here, 
> and then ...
>>> - rep->length = npixels + (nbytesRound >> 2);
>> + rep->length = npixels + num_dwords_for_bytes(nbytesRound);
>> Is it really worth replacing a two-bit shift with a function call?

yes, IMO. 
- functions for common operations reduce the chance of bugs in those
 operations.
- readability. I claim that having a meaningful name for a common operation
 is easier to read.
note that the instances replaced (most of them, anyway) are protocol
handling - doubtfully the most performance-critical part.
Cheers,
 Peter