[FFmpeg-devel] [PATCH 0/2] Origin Wing Commander IV video decoder

Benoit Fouet benoit.fouet
Thu Feb 3 14:42:15 CET 2011


Hi,

On Thu, 03 Feb 2011 14:02:12 +0100 Diego Biurrun wrote:
> On Thu, Feb 03, 2011 at 01:28:23PM +0100, Benoit Fouet wrote:
> > On Thu, 03 Feb 2011 12:30:17 +0100 Diego Biurrun wrote:
> > > On Thu, Feb 03, 2011 at 10:32:25AM +0100, Kostya wrote:
> > > > +static int xan_unpack_luma(const uint8_t *src, int src_size, uint8_t *dst, int dst_size)
> > > 
> > > Long line; src_size and dst_size should be const.
> > > 
> > > > +   uint8_t *dst_end = dst + dst_size;
> > > > +   const uint8_t *src_end = src + src_size;
> > > 
> > > dst_end should be const as well.
> > > 
> > > > +/* almost the same as in xan_wc3 decoder */
> > > > +static int xan_unpack(uint8_t *dest, int dest_len, const uint8_t *src, int src_len)
> > > 
> > > Long line; dest_len and src_len should be const.
> > 
> > There is very little point in having them const.  Could you clarify why
> > you want them to be?
> 
> I'm somewhat surprised by your question - because they are not changed
> inside the function?  Was there ever another reason to declare something
> const?
> 

And even though they were changed, why would that matter anyway?
You're passing a value to the function, you don't care about it being
modified or not. Do you really think that that will save 2 registers
(or 2 int in the stack) when compiled with a const?

-- 
Ben



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