IR sensor code

#include <msp430.h>
volatile unsigned int start_time;
volatile unsigned int stop_time;
volatile unsigned int max_time;
volatile unsigned int counter = 0;

#pragma vector = TIMER0_A1_VECTOR
__interrupt void counter1(void){
    counter++;
    TA0CTL &= ~TAIFG;
}

#pragma vector = PORT1_VECTOR
__interrupt void IR_SENSORS(void){
    if((P1IFG & 1) != 0){
        start_time = counter;
        max_time = TA0CCR0 * 2000;
        if((P1IN & 1) != 0){
            stop_time = start_time;
            if(stop_time < max_time){
                P2OUT ^= 1<<3;
            }
        }

        P1IFG &= ~1;
    }
    if((P1IFG & 1<<1) != 0){
        P2OUT ^= 1<<4;
        P1IFG &= ~(1<<1);
    }
    if((P1IFG & 1<<2) != 0){
        P2OUT ^= 1<<5;
        P1IFG &= ~(1<<2);
    }
}

int main(void){
      WDTCTL = WDTPW | WDTHOLD;    // stop watchdog timer
      DCOCTL = CALDCO_1MHZ;
      BCSCTL1 = CALBC1_1MHZ;

      TA0CTL |= TASSEL_2 | ID_1 | MC_1 | TAIE; //1 SEC = 1MHZ.
      TA0CCR0 = 1000; // 1ms
    P2DIR |= 1<<3 | 1<<4 | 1<<5;
    P2OUT |= 1<<3 | 1<<4 | 1<<5;

    P1DIR &= ~(1 | 1<<1 | 1<<2);
    P1REN |= 1 | 1<<1 | 1<<2;
    P1OUT &= ~(1 | 1<<1 | 1<<2);

    P1IE |= 1 | 1<<1 | 1<<2;
    P1IES &= ~(1 | 1<<1 | 1<<2);

    __enable_interrupt();



    while(1){

    }

    return 0;
}