What is the size of long long integer in a 32-bit computer?

Question

#include<stdio.h>
int main()
{
     unsigned long long var = 0LL;
     printf("%d",sizeof(var));
     return 0;
}

See: [http://stackoverflow.com/questions/1458923/long-long-in-c-c](http://stackoverflow.com/questions/1458923/long-long-in-c-c) — Rotem, Sep 15 '16 at 16:57
According to your program, the size is `Segmentation fault (core dumped)`, right? — Sergey Kalinichenko, Sep 15 '16 at 17:00
Even an 8 bits machine is able to emulate 64 bits long long variable. It is compiler dependent. I think C99 compliant compiler defines long long as 64 bits even in 32 bits machine. — Rotem, Sep 15 '16 at 17:02

chux - Reinstate Monica · Answer 1 · 2022-09-25T11:55:01.550

What is the size of long long integer in a 32-bit computer?

The type of computer is irrelevant. The value of the long long variable/object is irrelevant. The issues are the compiler and the C spec.

C requires long long to represent a minimum range or [-9223372036854775807 ... 9223372036854775807], that takes at least 64-bits (See C11dr §5.2.4.2.1 1).

A 32-bit computer will likely use a 64-bit implementation. A future compiler may use 128-bit long long.

When printing, use a matching print specifier "%zu" for the return type of sizeof, which is size_t.

#include <stdio.h>
#include <stdlib.h>

int main(void) {
  printf("size: %zu\n", sizeof(long long));
  printf("bit size: %zu\n", sizeof(long long) * CHAR_BIT);
}

printf(sizeof(var)); is invalid code as the first parameter to printf() needs to be a string, not an integer. Insure your compiler warnings are fully enabled.

Can you please add references? – Rotem Sep 15 '16 at 17:10 — Rotem, Sep 15 '16 at 17:10
@Rotem reference added. – chux - Reinstate Monica Sep 15 '16 at 18:01 — chux - Reinstate Monica, Sep 15 '16 at 18:01

What is the size of long long integer in a 32-bit computer?

1 Answers1