[MLton-devel] MLton and profiling

[Stephen Weeks]

Thanks for all the feedback, Joe.  It was very helpful.

> why doesn't MLton support a --version flag?

You can call "mlton -v" to find out the version number.

> My problem is functions like:
> 
> function composition;
> fun ## (f,g) (x,y) = (f x, g y);
> fun total f x = SOME (f x) handle ERR _ => NONE;
> 
> They all show up on the call graph as hugely important, with large
> numbers of called and caller functions, but I use these functions like
> simple macros to inline. [Sometimes just to improve the layout of code
> on the page: (f o g o h o j) x versus f (g (h (j x))).] I'm rather
> horrified at the thought that MLton might be treating them as
> functions instead of inlining them, but even if so I'd still like a
> way of suppressing them in the call graph.

Don't worry.  MLton is certainly inlining them.  You see a single node
in the call graph because the profiling infrastructure combines all of
the copies into a single graph node for reporting purposes.  The
thinking at the time was to keep information related to the source,
which only had one ## function, and that the inlining (or duplication
for other reasons) was an implementation detail.  However, I now think
that it is better to go the other way, and to keep whatever duplicates
the implementation creates separate.  I have changed the profiling
infrastructure to do so.  If I get requests from people for the old
combining behavior, I'll add a -coalesce switch to mlprof.

> Considering the function
> 
> fun f n = (g o h) n;
> 
> I believe at the moment this would be represented as a call from f to
> o, and a call from o to g and h. I'd much prefer this to be treated as
> a call from f to g and h. After all, I could insist on this simply by
> tweaking the code to be
> 
> fun f n = g (h n);
> 
> This is obviously a completely trivial example, but I hope you see my
> point.

Definitely.  I've added a -ignore flag to mlprof that should let you
get what you want.  Now you can do

	mlprof -ignore 'o' z mlmon.out

to ignore all functions named 'o'.  With -show-line true this becomes

	mlprof -show-line true -ignore 'o .*' z mlmon.out

Since -ignore takes a regexp, you can use it with -show-line true to
ignore whole files or directories from your project.

There's a new experimental release of MLton, 20030209, at

	http://www.mlton.org/experimental/

This release has the basis library fix for Word, as well as the
profiling improvements.


-------------------------------------------------------
This SF.NET email is sponsored by:
SourceForge Enterprise Edition + IBM + LinuxWorld = Something 2 See!
http://www.vasoftware.com
_______________________________________________
MLton-devel mailing list
MLton-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/mlton-devel