[MLton-user] more optimization questions

brian denheyer briand@aracnet.com
Wed, 21 Dec 2005 21:41:58 -0800

> I don't think that's necessary for the approach I described, which has
> both the advantage of not needing to modify input SML program as well
> as a performance advantage.  To be more clear, here's what I did.  I
> started with a vanilla install of MLton 20051202.  I then did two
> things.
>   * Eliminated the definition of abs from line 91 of
>     lib/mlton/sml/basis/real/real.fun
>   * Added a line to lib/mlton/include/c-chunk.h
>     #define Real64_abs fabs

Thanks for the info.  I definitely would not have figured that out.   
Especially since what I did worked.

> Perhaps this difference may explain why I saw a better speedup than
> you.

OK - I made the change and now I see 3.9s and 4.9s, now only 25%  
difference.  Quite good !

> speed and C-style correctness :-) if they want.  But they can do it
> selectively and lazily, only after profiling shows it would help a
> particular hot loop in their programs.

That sounds very useful.

Thanks again.