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[Bug fortran/53957] Polyhedron 11 benchmark: MP_PROP_DESIGN twice as long as other compiler
- From: "burnus at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Wed, 18 Jul 2012 14:04:45 +0000
- Subject: [Bug fortran/53957] Polyhedron 11 benchmark: MP_PROP_DESIGN twice as long as other compiler
- Auto-submitted: auto-generated
- References: <bug-53957-4@http.gcc.gnu.org/bugzilla/>
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53957
--- Comment #6 from Tobias Burnus <burnus at gcc dot gnu.org> 2012-07-18 14:04:45 UTC ---
Created attachment 27823
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=27823
Draft patch: Change comparison into bool assignment, decrement conditional jump
(In reply to comment #5)
> If you do
> exit = countm1 == 0;
> countm1--;
> > if (exit) goto exit_label;
> it would work for this case.
If I apply the attached patch, I do not see any performance difference on my
AMD Athlon64 x2 4800+ with -Ofast -funroll-loops -march=native.
real 3m45.711s 3m45.589s 3m44.308s | 3m45.363s 3m45.328s 3m44.220s
user 3m45.710s 3m45.582s 3m44.274s | 3m45.282s 3m45.286s 3m44.218s