[Bug fortran/32382] New: missed optimization in internal read

["manfred99 at gmx dot ch" <gcc-bugzilla at gcc dot gnu dot org>]

This is a followup to BUG 32257.
Above Bug has been resolved as invalid, but how comes that
the loop variable i has the value 101 at the end of the read?

consider
C234567
      program internalread
      implicit none
      integer m
CC      parameter(m=100)
      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,err=20) (intvalues(i),i=1,m)
20      write(*,*) j
      ENDDO
      end program internalread

(There is no access to i after the loop, so this program 
should be valid)

m=100:
gfortran needs 0.003s
g77 needs 0.002s

m=1000000:
gfortran needs 0.8s
g77 needs 0.002s

So gfortran loops to its bitter end, although it could 
shortcut the loop. g77 seems to exit the loop at i=3, as
BUG 32257 shows as well.


-- 
           Summary: missed optimization in internal read
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: manfred99 at gmx dot ch


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32382