gcc opteron define switch

[Ilgis Ibragimov]

Hello,

I would like to write a "C" program that is compatible in x32 and x64
Linux system under GCC environment.
Hence I need a a variable that is definite in x64 and indefinite in x32.
Certainly I can do in as -Dsomething, but I expect that compiler have
some own options.

Would you please to suggest me what kind of variable is definite in x64
and indefinite in x32?

Thank you

Ilgis

 

[Jens.Toerring]

I would like to write a "C" program that is compatible in x32 and x64
Linux system under GCC environment.
Hence I need a a variable that is definite in x64 and indefinite in x32.
Certainly I can do in as -Dsomething, but I expect that compiler have
some own options.

That's not a C question but something specific to your compiler.
I would recommend that you ask that in e.g. gnu.gcc.help where
it is not only on-topic but where you will find the people that
know most about these problems.
Regards, Jens

 

[Mark A. Odell]

Hello,

I would like to write a "C" program that is compatible in x32 and x64
Linux system under GCC environment.

But a major point of C is to be platform neutral. There are no x86
switches in the C language. There is no assumed operating system or
compiler. Once you start specifying such things you need to seek an
newsgroup that discusses such things. comp.unix.programmer springs to mind
in this case.

 

[CBFalconer]

I would like to write a "C" program that is compatible in x32 and
x64 Linux system under GCC environment.
Hence I need a a variable that is definite in x64 and indefinite in x32.
Certainly I can do in as -Dsomething, but I expect that compiler have
some own options.

Would you please to suggest me what kind of variable is definite in x64
and indefinite in x32?

Exactly what you want is not clear - there is a language barrier.
However I expect you should find suitable values via the
definitions in <limits.h>.

 

[Ilgis Ibragimov]

Hello,

thank everybody who answered to me. I found it in limits.h, there is
__WORDSIZE, and it is definite as 32 for x32, and 64 for x64.

Regards

Ilgis

 

[CBFalconer]

thank everybody who answered to me. I found it in limits.h, there is
__WORDSIZE, and it is definite as 32 for x32, and 64 for x64.

That is a non-portable system value, which you should not use.
Use only the values that are defined in the standard. That
includes such things as INT_MAX and INT_MIN.