Make constants such as NORTH and SOUTH into defines

ID:1277182
 
May 27 2013, 7:43 am
Applies to:DM Language
Status: Open
Issue hasn't been assigned a status value.
They're constants right now, which means that referencing them is hilariously slow (although, you can change them at runtime!) because each usage of them generates a GET instruction instead of PUSH (which is a whole shitload faster)
May 27 2013, 10:44 am (Edited on May 27 2013, 10:50 am)
I'm pretty sure there are constants to avoid future problematic reasons. If they are defines, they will not show up in the debugger. With a constant, you can pin-point its address, e.t.c. For the record, any modern C/C++ compiler should optimize a constant as if it were a define. There are scenarios you need to carefully consider when choosing between the two.
May 27 2013, 11:00 am
Guess what
BYONDs compiler has no optimization
May 27 2013, 1:34 pm
And while you're at it, shorten their names to single-letter defines. Typing out all those extra letters is sure to slow game design to such a crawl that no one will be able to create games, because of this immensely missing optimization.

Hm.
May 27 2013, 2:36 pm
Oh jesus christ people

The point is that for example
return NORTH

Generates the bytecode
get global<NORTH>
retval

instead of
push 1
retval
May 28 2013, 3:26 am
In response to Tobba
Tobba wrote:
Oh jesus christ people

The point is that [snip...]

I'm well aware of what the point is. Did you understand my point, though?

Your request is slightly similar to a situation with my algorithms professor, who spent 6 months on a paper that no one would publish. In it he detailed eliminating certain optimized statements and replacing them with something similar, thus saving 45 nanoseconds for arrays of sizes 2^48 and above, or so. It simply does not matter, ever.
May 28 2013, 4:15 am
Except decoding a variable reference coupled with a variable lookups is extremely slow
May 28 2013, 4:29 am
 
#define DEBUG

world
    loop_checks = 0

mob/verb/Test()
    var/start = world.timeofday
    for (var/i = 0; i < 10000000; i++)
        abs(NORTH)
    world << world.timeofday-start

mob/verb/Test2()
    var/start = world.timeofday
    for (var/i = 0; i < 10000000; i++)
        abs(1)
    world << world.timeofday-start



18
15


Thats a 16% speedup
(It'll complain that the statements have no effect, and then compile them in anyways, woo)

You'd notice a greater speedup if it wasent for that loops are extremely slow
May 30 2013, 12:03 pm
The fact that you're referencing a 16% relative speedup means that you've 100% missed the point. Oh well.
Jun 1 2013, 7:53 am
In response to Tobba
Tobba wrote:
Guess what
BYONDs compiler has no optimization

That's where the real problem is in this case.
Jul 10 2013, 8:06 am
Bumping this since we got math optimizations, it shouldent break anything if changed, but code that references these a lot in big loops get a decent speedup