The code was not doing well on the SGI Power Challenge, because the driver routine used a variable tol which is not defined and thus assuming the value of 0. This caused the final control returns with ierr = 5 and prints out with ``no solution''. It should be rntol, which is the stopping criterion.
Affected routine:mgftoc.f, ftoc.f, mgcw.f.
The initial 2-norm residual is computed before the multigrid cycle is started. Two variable res_norm0 and res_norm are added in mgcw.f. The stopping creterion has been changed to based on the reduction of res_norm/res_norm0.