How to get gcc to produce 64 bit code? m64 option produces "sorry" message!!

[mprogrammer]

Hello programmers,

I have a question about the options of gcc. I have a 64 bit processor with a fedora 64 bit running on it. Both int and long are 32 bit long and long long is 64. when I use the -m64 option that I found info about somewhere online, the gcc responds with: sorry, unimplemented: 64 bit mode not compiled in.

What can I do to fix that?

Thank you,

[MK27]

If you are running FC-64, gcc is producing 64-bit code, you don't need to use a switch.

Int is still a 4 byte value. "64-bit" refers to the memory addressing. So the difference is in the sizeof() pointers. If you check, all your pointers are 8 bytes long, to hold a 64-bit address. 32-bit pointers are 4 bytes.

[mprogrammer]

So I understand that gcc defines int to be 4 byte long on both 32 and 64 bit machines?

Thanks