64 bit CPU unsigned long int

GodSendDeath · 03-28-2005, 02:12 PM

Please correct me if im wrong...

In a 32 bit CPU, the "unsigned long int" data type has a max value of
(2^32)-1....

In a 64 bit CPU (AMD64 for example), will the "unsigned long int" data type
have a max value of (2^64)-1?

I am working on a Solaris Sparc III machine which consists of 64 bit CPUS. However, the unsigned long int number appears to be restricted to the legacy 2^32 size. This may be due to admin configuration (not my server). Any information would be appreciated.

-GSD

alred · 03-28-2005, 02:36 PM

maybe you can try :

signed long long int
unsigned long long int

itsme86 · 03-28-2005, 02:46 PM

According to the C standard, a long int has to be at least as big as an int. But it doesn't say anything about how big it will be on whatever architecture. If you need the int to be a certain size (64-bit) then I suggest #include'ing <stdint.h> and using the type uint64_t.

Nerox · 03-28-2005, 03:42 PM

You can also use the __u64 (and all its variants) type by including <linux/types.h>

GodSendDeath · 03-28-2005, 03:43 PM

Thanks for the quick response. Ill try all suggestions and post any interesting results.

-GSD

Nerox · 03-28-2005, 04:04 PM

Quote:

Originally posted by Nerox
You can also use the __u64 (and all its variants) type by including <linux/types.h>

I'm sorry, i've thought it more thoroughly, and my proposal won't work on your machine, since your machine is running a Sun Solaris and not a Linux system. That will only work on Linux.

GodSendDeath · 03-28-2005, 04:07 PM

No Prob. Ive got several to work with... Solaris, FreeBSD, and Linux. Its just Solaris was the only 64 bit architecture I had to work with.

-GSD

skie_knite007 · 03-29-2005, 11:05 AM

It depends on the compiler u r using,I think so.

If u r using GCC,,its 32 bit compiler. So the unsigned int ll be only
2^32-1

itsme86 · 03-29-2005, 01:19 PM

Quote:

Originally posted by skie_knite007
It depends on the compiler u r using,I think so.

If u r using GCC,,its 32 bit compiler. So the unsigned int ll be only
2^32-1

Not true. These are compiler options for GCC:

Quote:

-m32
-m64
Generate code for a 32-bit or 64-bit environment. The 32-bit environment sets int, long and pointer to 32 bits and generates code that runs on any i386 system. The 64-bit environment sets int to 32 bits and long and pointer to 64 bits and generates code for AMD's x86-64 architecture.

Here's a link for reference: http://gcc.gnu.org/onlinedocs/gcc-3....002d64-Options