FIRSTARG
tf->tf_fixreg[FIRSTARG] = rval[0];
tf->tf_fixreg[FIRSTARG + 1] = rval[1];
tf->tf_fixreg[FIRSTARG] = error;
tf->tf_fixreg[FIRSTARG] = 0;
tf->tf_fixreg[FIRSTARG + 1] = 1;
params = tf->tf_fixreg + FIRSTARG;