> Guess I'll need to go read about -fno-strict-overflow. Using it make the failing test to pass: [karma] f90/bug% gfc -w -ffree-line-length-none -fno-range-check -O3 -fno-strict-overflow /opt/gcc/_gcc-clean/gcc/testsuite/gfortran.dg/do_3.F90 [karma] f90/bug% a.out [karma] f90/bug% Time to go to bed. Have a nice day. Dominique