FOR A=1 to 32
PORTA.0[A]=1
NEXT
Will make all ports of PORTA/PORTB/PORTC/PORTD high in sequence, right? (All TRIS and other yada-yada are already set).
Since you start your offset value (the FOR loop) at 1 it the first bit to be set will be "one away" from PortA.0, in other words PortA.1 and then contiune 32 bits "up from there", so you will write to the first bit of the register comming after PortD - that can ruin your day.

But, as Richard says, TRY IT for crying out loud :-) Investigate how it works, does it do what you expect, change something and see if you get the expected result and if not think about WHY.