MSP430FR6989: Shared vector ISR

#include <msp430.h> 
#define redLED BIT0 // Red at P1.0
#define greenLED BIT7 // Green at P9.7

int main(void)
{
    WDTCTL = WDTPW | WDTHOLD; // Stop WDT
    PM5CTL0 &= ~LOCKLPM5; // Enable GPIO pins
    P1DIR |= redLED;
    P9DIR |= greenLED;
    P1OUT &= ~redLED;
    P9OUT &= ~greenLED;

    TA0CCR1 = (12000 - 1);
    TA0CCTL1 &= ~CCIFG;
    TA0CCTL1 |= CCIE;

    TA0CTL = TASSEL_1 | ID_0 | MC_2 | TACLR;

    while (1) {}

	return 0;
}

#pragma vector = TIMER0_A1_VECTOR
__interrupt void T0A1_ISR()
{
    if ((TA0CTL & TAIFG) != 0){
        P1OUT ^= greenLED;
        TA0CTL &= ~TAIFG;
    }

    if ((TA0CCTL1 & CCIFG) != 0){
        P1OUT ^= redLED;
        TA0CCR1 += 12000;
        TA0CCTL1 &= ~CCIFG;
    }
}

// Configures ACLK to 32 KHz crystal
void config_ACLK_to_32KHz_crystal() {

    // By default, ACLK runs on LFMODCLK at 5MHz/128 = 39 KHz
    // Reroute pins to LFXIN/LFXOUT functionality
    PJSEL1 &= ~BIT4;
    PJSEL0 |= BIT4;
    // Wait until the oscillator fault flags remain cleared
    CSCTL0 = CSKEY; // Unlock CS registers

    do {

        CSCTL5 &= ~LFXTOFFG; // Local fault flag
        SFRIFG1 &= ~OFIFG; // Global fault flag

    } while((CSCTL5 & LFXTOFFG) != 0);

    CSCTL0_H = 0; // Lock CS registers
return;
}