Re: [Caml-list] Where does Ocaml spend all the time?

[Sven LUTHER <luther@dpt-info.u-strasbg.fr>]

On Thu, Jun 28, 2001 at 10:16:35AM +0200, Florian Hars wrote:
> I have written an ocaml program, which is about an order of magnitude
> slower than a similar C program, and now I am wondering what to do.
> According to gprof, I have neiter written nor called most of the
> top-scoring functions in my program:
> 
>   %   cumulative   self              self     total           
>  time   seconds   seconds    calls  ms/call  ms/call  name    
>   9.82      2.76     2.76  9822122     0.00     0.00  Verzeichnis_code_end
>   9.00      5.29     2.53     3275     0.77     0.77  mark_slice
>   8.15      7.58     2.29    17860     0.13     0.54  Stra$dfen_e_i_l_rec_129
>   8.04      9.84     2.26 23232718     0.00     0.00  string_equal
>   7.44     11.93     2.09     4088     0.51     0.62  sweep_slice
>   5.73     13.54     1.61   390646     0.00     0.01  oldify
>   4.16     14.71     1.17 22241546     0.00     0.00  Eintrag_code_begin
>   3.88     15.80     1.09                             Stringhilfsfunktionen_code_begin
> 
> Only the third and fourth entry seem to do anything "useful", the rest
> looks like administrative overhead to me. What are these functions
> doing?
> Are there any general hints on how to write ocaml programs for efficiency?
> Like, don't use functional updates for records to reduce garbage?

mmm, i am no expert, but the mark_slice and sweep_slice seems like
garbage_collector stuff.

I think there is a faq entry about efficiency and other such things, in
particular you have to know, please someone correct me if i am wrong, that the
updating of a reference or a mutable field can trigger a garbage collection.

Also ocaml is highly optimized for functional datatypes and curryified
function calls. 

Maybe this helps.

Friendly,

Sven Luther
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