IRQ meaning

Does using the __irq at the end of the function automatically calls itself when an interrupt occurs?
for e.g.

void ISR_TIMER0(void) __irq {

int interrupt;
//-------------------------- if( T0IR & _MR0 ) {
interrupt = _MR0;
if(isrT0MR0Handler != NULL)
(*isrT0MR0Handler)();
//call Timer0-Match0 handler function
}
else if( T0IR & _MR1) {
interrupt = _MR1;
if(isrT0MR1Handler != NULL)
(*isrT0MR1Handler)();
//call Timer0-Match1 handler function
}
else if( T0IR & _MR2) {
interrupt = _MR2;
if(isrT0MR2Handler != NULL)
(*isrT0MR2Handler)();
//call Timer0-Match2 handler function
}
else if( T0IR & _MR3) {
interrupt = _MR3;
if(isrT0MR3Handler != NULL)
(*isrT0MR3Handler)();
//call Timer0-Match3 handler function
}
else if( T0IR & _CR0) {
interrupt = _CR0;
if(isrT0CR0Handler != NULL)
(*isrT0CR0Handler)();
//call Timer0-Capture0 handler function
}
else if( T0IR & _CR1) {
interrupt = _CR1;
if(*isrT0CR1Handler != NULL)
(isrT0CR1Handler)();
//call Timer0-Capture1 handler function
}
//-------------------------- T0IR |= interrupt;
//clear interrrupt
//--------------------------
}

This is example of a interrupt function. Tell me the interrupt handler function and when will the function get called?