Hi Philipp
On Mon, Jul 18, 2016 at 3:13 PM, Philipp Zabel <p.zabel@xxxxxxxxxxxxxx> wrote:
> Since the constant expressions are evaluated at compile time, you are
> not actually removing shifts. The code generated for precalculate_color
> by gcc 5.4 even grows by one asr instruction with this patch.
>
I dont think that I follow you completely here. The original code was
if (a)
y= clamp(y, 16<<4, 235<<4)
y = clamp(y>>4, 1, 254)
And now is
if (a)
y= clamp(y >>4, 16, 235)
else
y = clamp(y, 1, 254)
On the previous case, when a was true there was 2 clamp operations.
Now it is only one.
Best regards!
--
Ricardo Ribalda
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