[Bug libfortran/20278] New: Performance regression in formatted output vs. g77

Thomas dot Koenig at online dot de gcc-bugzilla@gcc.gnu.org
Wed Mar 2 08:26:00 GMT 2005


$ cat write-many.f
      program main
      open(10,status='SCRATCH')
      a = 0.3858204
      do i=1,1000000
         a = a + 0.4761748164
         write(10, '(G12.5)'),a
      end do
      end
$ gfortran write-many.f
$ time ./a.out

real    0m8.165s
user    0m8.092s
sys     0m0.059s
$ g77 write-many.f
$ time ./a.out

real    0m5.760s
user    0m5.719s
sys     0m0.032s
$ gfortran -v
Using built-in specs.
Target: ia64-unknown-linux-gnu
Configured with: ../gcc-4.1-20050227/configure --prefix=/home/zfkts
--enable-languages=c,f95
Thread model: posix
gcc version 4.1.0 20050227 (experimental)

-- 
           Summary: Performance regression in formatted output vs. g77
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: libfortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: Thomas dot Koenig at online dot de
                CC: gcc-bugs at gcc dot gnu dot org
GCC target triplet: ia64-unknown-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20278



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