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* [Bug fortran/13465] New: [gfortran] Data statement for large errors compiles verrrry slllowwwly and shows quadratic behaviour.
@ 2003-12-22 13:03 toon at moene dot indiv dot nluug dot nl
  2003-12-22 13:51 ` [Bug fortran/13465] [gfortran] Data statement for large arrays " toon at moene dot indiv dot nluug dot nl
                   ` (9 more replies)
  0 siblings, 10 replies; 11+ messages in thread
From: toon at moene dot indiv dot nluug dot nl @ 2003-12-22 13:03 UTC (permalink / raw)
  To: gcc-bugs

This three line Fortran program (free format):

DIMENSION A(100000)
DATA A /100000*0.0 /
END

takes 48 minutes to compile on my 0.5 GHz G4 Powerbook.

If I reduce the extent of the array by 1/10th, it takes 30 seconds.

1. This is far too slow.
2. There's quadratic behaviour in the algorithm.

I think the integer computations to calculate offsets don't have to be done
using GMP routines, but can be expressed using variables of the ssizetype_t
type, just as in g77.

The quadratic effect is probably caused by the use of the expression stack.
I hope someone can suggest a better datastructure for this work.

-- 
           Summary: [gfortran] Data statement for large errors compiles
                    verrrry slllowwwly and shows quadratic behaviour.
           Product: gcc
           Version: tree-ssa
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: toon at moene dot indiv dot nluug dot nl
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13465


^ permalink raw reply	[flat|nested] 11+ messages in thread
end of thread, other threads:[~2004-08-23 22:07 UTC | newest]

Thread overview: 11+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2003-12-22 13:03 [Bug fortran/13465] New: [gfortran] Data statement for large errors compiles verrrry slllowwwly and shows quadratic behaviour toon at moene dot indiv dot nluug dot nl
2003-12-22 13:51 ` [Bug fortran/13465] [gfortran] Data statement for large arrays " toon at moene dot indiv dot nluug dot nl
2003-12-28  3:08 ` pinskia at gcc dot gnu dot org
2004-03-28  7:45 ` pinskia at gcc dot gnu dot org
2004-05-26 23:04 ` pinskia at gcc dot gnu dot org
2004-06-04 13:02 ` tobi at gcc dot gnu dot org
2004-06-04 13:33 ` tobi at gcc dot gnu dot org
2004-08-19 14:14 ` [Bug fortran/13465] " pinskia at gcc dot gnu dot org
2004-08-23 21:53 ` cvs-commit at gcc dot gnu dot org
2004-08-23 22:05 ` rth at gcc dot gnu dot org
2004-08-23 22:07 ` pinskia at gcc dot gnu dot org

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