On Sunday, 26 June 2016 at 13:59:03 UTC, Andrei Alexandrescu
wrote:
On 6/26/16 9:47 AM, Manu via Digitalmars-d wrote:
Hi people. I've been working on this colour library when I
have free
time (almost never!), and I want to work on blending/filtering
functions, but that work is kinda blocked by saturating
arithmetic
logic.
I started working on a saturating integer library a few times,
but
it's much a much bigger job than it appears, and I haven't had
enough
time for it. (Efficient) implementation tends to be
significantly
different for every int width and signed/unsigned. I see no
use for an
inefficient implementation used by a colour library; images
tend to be
millions of pixels, and inefficiency very quickly adds up.
See the recent thread "DbI checked integral". Saturation is a
direct goal, and you should be able to optimize operations for
each type by defining relatively small hooks.
No, saturated operations are typically SIMD instructions.
