Compare speed signal n change PWM accordingly

Hello all,

I am working with AT89C51CC01.(based on 8051)
My task is to Compare speed signal of Motor n change PWM accordingly.

In my program..after PWM start..interrupt start (on P3_2 n P3_3 
connected with Hall Sensor)..then i have to measure the signal of P3_2 n 
signals of P3_3 (may same or different)..n then according to this signal 
i have to change PWM..

For that i had write one program.(See attachment)
please check the code n also read comment in attached file.

Is there any problem in this code.
If anyone have any idea or suggestion to implementing this task 
(Controlling speed of motor & change PWM according to speed of motor), 
then please reply me

Thanks in advance