Original define in the NVIDIA docs #define IDX2F(i,j,ld) ((((j)-1)*(ld))+((i)-1)) has no space between IDX2F and (i,j,ld). If there is the mistaken space then the IDX2F is substituted by (i,j,ld) ((((j)-1)*(ld))+((i)-1)) that is not expected. Since a fixed format is used for Fortran source then due to extra `(i,j,ld) ` resulting string exceeds 72 symbols and some right parenthesis 'are eated'. However, the used define operator has correct numbers of the left and right parenthesis.