_REG_R0
gr[_REG_R0 + i] = va_arg(ap, int);
gr[_REG_R0] = (__greg_t)sig;
gr[_REG_R0] = r->r[0];
r->r[0] = gr[_REG_R0];
gr[_REG_R0] = 0;
gr[_REG_R0] = tf->tf_r0;
tf->tf_r0 = gr[_REG_R0];