[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" <gcc-bugzilla at gcc dot gnu dot org>]

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