gfortran -v
GNU Fortran (GCC) 4.4.0 20080919 (experimental)

[~/tmp]$gfortran test.f90  -floop-block -O2
test.f90: In function 'main':
test.f90:1: internal compiler error: Segmentation fault
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.

the fortran source:

program main
implicit none
integer,parameter :: N=900
real(kind=8) :: x(N)
integer(kind=4) :: i
do i=1,N
x(i)=sin(real(i,8))
end do
print *, sum(x)
end program main