When porting 32bit code to 64bit code.. will the compiler automaticly convert
Inc/Dec instructions to Add/Sub instructions? Inc/Dec bytes are used for the REX prefix on 64bit machines and are now obsolite.

Or do we need to define new inc & dec macro's to do the inc/dec convertion. I dont have a 64bit system and havn't been able to any debug testing.

INC/DEC still exist in 64-bit code, since only their short forms for registers (opcodes 40h-4Fh) have been used for other purposes, and their long forms (opcodes 0FEh-0FFh) are still available.

Any such "conversion" would not be suitable, since "INC EAX" is not the same as "ADD EAX,1" - the second one affects CF, while first one doesn't. This is important and utilized feature - thus they could not remove the INC/DEC from the instruction set.