add Operation Font Conventions
if (PR[qp]) {
check_target_register;

if (register_form) // register form
tmp_src = GR[r2];
else if (imm14_form) // 14-bit immediate form
tmp_src = sign_ext(imm14, 14);
else // 22-bit immediate form
tmp_src = sign_ext(imm22, 22);

tmp_nat = (register_form ? GR[r2].nat : 0);

if (plus1_form)
GR[r1] = tmp_src + GR[r3] + 1;
else
GR[r1] = tmp_src + GR[r3];

GR[r1].nat = tmp_nat || GR[r3].nat;
}