Does GCC support long long int?

Question

Does GCC support:

long long int

which would be a 64-bit integer?

Also, is long long int part of the standard?

Answer 1

Yes GCC does support long long int, which is a part of C99 standard.

The standard does not mandate its size in bits, but required values of LLONG_MIN and LLONG_MAX in <limits.h> imply it's at least 64-bit (exact 64-bit wide integer types are int64_t/uint64_t from <stdint.h>).

1. LLONG_MIN must be at most -9223372036854775807
2. LLONG_MAX must be at least 9223372036854775807

Answer 2

long long int is a part of the C99 standard, and I know GCC supports it. And now I can prove it.

Answer 3

On my 32-bit machine,

int main()
{
    printf("%d\n", sizeof(long long int));
    return 0;
}

compiled with gcc prints 8 (8 bytes * 8 bits/byte = 64 bits).