1! { dg-do run } 2! 3! PR fortran/40675 4! 5! Fortran 77 just had: "The value of a signed zero is the same as 6! the value of an unsigned zero." and g77 returned for SIGN(1.0, -0.0) = 1.0 7! 8! Fortran 95+ has for SIGN: "Case (iv): If B is of type real and is zero, 9! then ... (c) If B is negative real zero, the value of the result is -|A|". 10! On architectures, where signed zeros are supported, gfortran's SIGN thus 11! returns for B=-0.0 the -|A|. 12! 13program s 14 x = sign(1.,0.) 15 y = sign(1.,-0.) 16 if (x /= 1.) STOP 1 17 if (y /= -1.) STOP 2 18 x = 1. 19 y = 0. 20 x = sign(x, y) 21 y = sign(x, -y) 22 if (x /= 1.) STOP 3 23 if (y /= -1.) STOP 4 24end program s 25