Question

I am using __int64 datatype on 64 bit AIX and I am getting bizarre results in the case of comparison with 0.

Code snippet :

__int64 indexExistingPart =  GetValue(); // GetValue always returns -1.

if (indexExistingPart < 0 )
{
    DoSomething(); //control never comes to this part of the code
}

I have also tried assigning 0 to another __int64 variable and used in in the comparison. However, this also did not work:

__int64 indexExistingPart =  GetValue(); // GetValue always returns -1.

__int64 temp =0;

if (indexExistingPart < temp )
{
    DoSomething(); //control never comes to this part of the code
}

Why comparison operator is not working for 64 bit integers? Is there any workaround?

Answer 1

The symptoms are consistent with __int64 being a typedef for unsigned long in your project. (__int64 is not a type provided by AIX, at least according to the IBM docs.) Try this instead:

#include <stdint.h> // or #include <sys/types.h>, or #include <inttypes.h>

int64_t indexExistingPart = GetValue();  // or "signed long indexExistingPart ..."

if (indexExistingPart < 0 )
{
    DoSomething();
}