Detecting 64bit compile in C

Question

is there a C macro or some kind of way that i can check if my c program was compiled as 64bit or 32bit at compile time in C?

Compiler: GCC Operating systems that i n

Answer 1

Use this UINTPTR_MAX value to check build type.

#include 
#include 

#if UINTPTR_MAX == 0xffffffffffffffffULL               
# define BUILD_64   1
#endif

int main(void) {

    #ifdef BUILD_64
    printf("Your Build is 64-bit\n");

    #else
    printf("Your Build is 32-bit\n");

    #endif
    return 0;
}