x86 32-bits compiler use on a 64-bits machine ?

[Christophe LYON]

Hi Andrew,

Thanks for your answer.

>> The documentation only mentions the size of int and pointer types.
> 
> The gcc documentation talks only about gcc; you're asking about the
> system linker.
> 

I did not mean that.
If I compile a.c with "gcc-x.x.x (32 bits)" on a Pentium 4 machine, and 
with "gcc-x.x.x (64 bits) -m32" on an Opteron, am I guaranteed that both 
a.o will have the same contents?
Any risk that the file compiled on Opteron contains Opteron-only 
instructions for instance? Or references only 64 bits variants of some 
system structures?

If I compile a.c with "gcc-x.x.x (32 bits)" on a Pentium 4 machine, and 
b.c with "gcc-x.x.x (64 bits) -m32" on an Opteron, I need to be able to 
link a.o and b.o together and that the result is actually meaningful on 
a Pentium 4.

Regards,

Christophe.