------- Comment #1 from kargl at gcc dot gnu dot org 2009-06-01 06:54 ------- (In reply to comment #0) > Complex division by zero in gfortran returns NaN. This is expected for 0/0, > but other finite/zero should return Inf. This impacts the testcase > gfortran.dg/real_const_3.f90 in two values incorrectly computed: > > complex :: z = (-0.1,-2.2)/(0.0,0.0) > complex :: z2 = (0.1,1)/0 > > See: http://gcc.gnu.org/ml/fortran/2009-05/msg00423.html > > This should be fixed in gcc-4.5 by using MPC for division, but older versions > of GCC should add special case handling in the fortran frontend simplification > code. >
Kaveh, After looking into the problem, I think (nan + i nan) is an acceptable result for z = (-0.1,-2.2)/(0.0,0.0) because of the standard definition of complex division. For z2 = (0.1,1)/0, I think that you are correct, and gfortran should give (inf + i inf). -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40318
