Hello!

I need to support 64bit data type(like int64)with gcc compiler. Is there any option to do this?

thank you.

It's called "long long". The unsigned version is called (obviously) "unsigned long long".
Thus if you have declared "long long n", then n can store values in [-2^63,2^63) (signed), or in [0,2^64) (unsigned).

If you're using C, then "long long" is part of the standard (C99) and is the official name for it.
If you're using C++, then C++ has no standard 64-bit integer datatype, but most compilers support it. The M$ compilers call it int64, I guess, and gcc calls it "long long". (Also, it is quite likely that 64-bit integer datatypes will become part of the C++ standard the next time a standard is discussed, and it will be called long long.)

Thank you for your help!!
The long long data type works well in my system.
But it takes some time to verify it.
Because I cannot print long long data type using "printf()" function.
I think printf() do not support long long data type. So, I print it using bit shift like below. ^^

unsigned long long value ;
value = 0xffffffffff;
printf("value %08x%08x\n", (int)(value>>32), (int)value);

The "%lld" (or "%llu" for unsigned) format specifier should work. Have you tried it?

Thanks a lot.
That specifier works well.

I have a question. I cannot find that specifer by using "man" and "info" command.
Where can i find it in detail? I hope I can find it in web site.

Thanks.

I found those specifiers in the man page.

Simply running "man printf" yields information on the shell printf command. Try running "man 3 printf" instead.

You are right. I checked it. Thanks you

You're welcome. Glad I was able to help.