void test(unsigned int ival);

Don't forget that the 8051 is an 8-bit processor; an int is most likely to be 16 bits - so the compiler will have to generate code to cope with the 2-byte value.
Unless you really need to pass 16 bits (which isn't the case in your example), avoid int - use unsigned char instead.

Better still, create your own typedefs such as U8, U16, etc so that your data sizes (and signedness) are independent of the implementation.