[Bug fortran/53029] New: missed optimization in internal read (without implied-do-loop)

manfred99 at gmx dot ch gcc-bugzilla@gcc.gnu.org
Wed Apr 18 12:57:00 GMT 2012


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53029

             Bug #: 53029
           Summary: missed optimization in internal read (without
                    implied-do-loop)
    Classification: Unclassified
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: manfred99@gmx.ch


Followup to Bug 32382.

!234567C234567
      program internalread
      implicit none
      integer m
      parameter(m=1000000)
      character value*10
      integer i,j,intvalues(m)

      DO j=1,100
        write(value,'(i3,a5)') j," 5 69"
        write(*,*) value
!!        read(value,*,end=20) (intvalues(i),i=1,m)  ! this is BUG 32382
        read(value,*,end=20) intvalues
   20   write(*,*) j,(intvalues(i),i=1,4)
      ENDDO
      end program internalread

This version needs 2.7s on my box, the commented version
needs 0.27s (BUG 32382).

The array version is about 10x slower than the implied do loop variant.



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