https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77278
--- Comment #2 from Thomas Koenig <tkoenig at gcc dot gnu.org> --- Here's a test case which shows a performance loss with LTO-enabled libgfortran. program main implicit none integer, parameter :: n=10**7 integer :: i real, dimension(n) :: a real :: t1, t2, t3 call random_number(a) call cpu_time(t1) write (20,'(E17.12)') a call cpu_time(t2) write (21,'(E17.12)') (a(i),i=1,n) call cpu_time(t3) write (*,*) 'array write: ', t2-t1 write (*,*) 'implied write: ', t3-t2 end program main Running three times with shared libraries: array write: 12.0480003 implied write: 11.8389988 array write: 12.5640001 implied write: 12.5340004 array write: 11.8710003 implied write: 12.1729994 Running three times with LTO: array write: 14.9330006 implied write: 15.3499994 array write: 14.2670002 implied write: 14.8539991 array write: 13.7550001 implied write: 14.8719997 So, it is not always all that clear.
