Re: use ADA !
but the compiler produces the same code whether you use a=b[x++] or a=b[x];x=x+1.
Possibly, but that would depend on the compiler itself actually.
The autoinc/decrement was introduced because some architectures introduced specific increment and decrement instructions in their instruction sets, and using a++ vs a=a+1 could produce different assembly.
e.g. (pseudo assembly)
a++
LOAD A R1
INC R1
STORE R1 A
but a=a+1
LOAD A R1
LOAD 1 R2
ADD R1 R2
STORE R1 A
May not look much, but if you are iterating through a million increments of 1, that extra instruction and the two additional register accesses required can add a lot of overhead.
Of course, smart optimising compilers should recognise a=a+1 and output the assembly equivalent to a++.