🚀 go-pugleaf

ematias@csri.toronto.edu (Ummm... me!) writes:

>   This is totally baffling me, since I can't comprehend why my program
>would be BIGGER and SLOWER just because the number of elements in a struct
>isn't a multiple of 16 -- and furthermore, why it works fine for only
>a select few multiples of 16.  Help!

It is because pointer arithmetic is more efficient with powers of two.
If the size of your struct is a power of two, then pointer manipulations
(and array offset calculations) can be performed with simple shift
instructions, whereas non-power-of-two-sized elements require slow
multiply and division operations, which both increase the size of your
code and slow down the program.  Exactly what you observed.

-- 
#ifdef TRUE        | Fuzzy Fox (a.k.a. David DeSimone)       fuzzy@netcom.com
#define  TRUE   0  |
#define  FALSE  1  |  "You have been recruited by the Star League to defend
#endif             |     the Frontier against Xur and the Kodan Armada."