[MLton-user] Tracking down allocations

[Joe Hurd]

Hi Ville,

Thanks for the inlining suggestion: it reduced the allocations by 25%
and also gave the program an overall speed-up of 20%. However, there
are still 30,000,000,000 allocations at the program point in my first
email that I can't explain.

I'm a little puzzled by why allocations are done at all when calling
functions. All my functions are first order (though as I showed some
are nested), so I assumed that calling them would simply be a case of
putting the arguments on the stack. Most of them are curried,
including the one that is causing all the allocations. I was also
careful to ensure that the return type of all the critical functions
was either unit or a simple type such as bool or int.

Does MLton "allocations" refer to stack manipulations as well as
allocating cells on the heap, or am I missing something?

Joe

On 7/15/07, Ville Laurikari <ville at laurikari.net> wrote:
> On Sun, Jul 15, 2007 at 01:44:32AM +0100, Joe Hurd wrote:
> > mlprof -show-line true -raw true x mlmon.out
> >
> > pointed me to the "let" line with 40,000,000,000 allocations being
> > done. Where exactly should I look next to see where the allocations
> > are being done?
>
> I did a similar excercise a few weeks ago.  I was able to eliminate
> all allocations in my program by compiling with "mlton -inline 100000"
> instead of the default.  Maybe that could help in your case as well?
>
> In my program, the allocations that weren't eliminated with default
> inlining were just argument tuples for a couple of functions.  The
> functions were extremely short and I would have thought they would
> have been inlined and the tuples eliminated, but that was not the
> case.
>
> --
> http://www.iki.fi/vl/
>