[m-users.] uncaught Mercury exception using mdprof_create_feedback

Matthias Guedemann matthias.guedemann at googlemail.com
Fri Oct 10 05:14:41 AEDT 2014

Hi Paul,

> parallelism, which is too little to measure.  I'll let you try it with
> my feedback file and see what you find.  Also you can see what the
> autoparallelisation recommends by using the mdprof_report_feedback
> tool to translate the feedback file into a human readable form.

> I also tried the --no-ipar-dep-conjs flag, in that case the automatic
> analysis chooses the ame parallelisation as you did, and predicts a
> speedup of 2.5.

It seems that both versions result in approximately the same speedup,
with a slight advantage for the implicit parallelism version.

On a dual core i5 with hyperthreading I get the following results using
the asm_fast.par.gc.stseg grade.

Two runs for the version of the feedback file:

./euler_82  167.20s user 0.10s system 275% cpu 1:00.68 total
./euler_82  177.42s user 0.09s system 294% cpu 1:00.18 total

and this for the manual version:

./euler_82  180.83s user 0.12s system 289% cpu 1:02.44 total
./euler_82  173.65s user 0.07s system 282% cpu 1:01.43 total

The non-parallel version in asm_fast grade gives:

./euler_82  91.04s user 0.06s system 99% cpu 1:31.37 total
./euler_82  91.55s user 0.05s system 100% cpu 1:31.50 total

Is this consistent with your experiences / expectations?

Best regards

More information about the users mailing list