p[1] vs. *(p+1)

[Martin Weitzel]

In article <1990Aug31.163647.11121 at zoo.toronto.edu> henry at zoo.toronto.edu (Henry Spencer) writes:
>In article <1745 at io.UUCP> prs at eng.ileaf.com (Paul Schmidt) writes:
[...]
>>So, that means that the compiler must know the size of the elements of
>>array p, and that *(p+1) does not add 1 to p, but instead adds
>>sizeof(array_element_type) to p?
[...]
>Ignoring some syntactic nit-picking, p[1] is *identical* to *(p+1), by
>definition of the C subscripting operation.

And in all flavours of UNIX I've ever used there is a compiler option
(usually -S) which leaves an assembly language file (usually suffixed .s) 
and I've never seen a difference in the assembly source for both
constructs

But note: The fact that *(p+1) can be interchanged with p[1] (and even
with 1[p]) does of course NOT mean that there is no difference between
pointers and arrays. With: T a[10], *ap = a; the machine code produced
for a[1] is DIFFERENT from the code for *(ap+1); but the latter is
the same as for ap[1] and the former is the same as for *(a+1). 
-- 
Martin Weitzel, email: martin at mwtech.UUCP, voice: 49-(0)6151-6 56 83