64-bit Differences

Sample Code

#include <stdio.h>    /* printf */

int main(void)
{
  printf("sizeof(short) is %lu\n", sizeof(short));
  printf("sizeof(int) is %lu\n", sizeof(int));
  printf("sizeof(long) is %lu\n", sizeof(long));
  printf("sizeof(long long) is %lu\n", sizeof(long long)); /* C99 */
  printf("sizeof(void*) is %lu\n", sizeof(void*));
  
  return 0;
}

Outputs:

32-bit Windows (Microsoft)

sizeof(short) is 2
sizeof(int) is 4
sizeof(long) is 4
sizeof(long long) is 8
sizeof(void*) is 4

32-bit Cygwin (gcc):

sizeof(short) is 2
sizeof(int) is 4
sizeof(long) is 4
sizeof(long long) is 8
sizeof(void*) is 4

64-bit Windows (Microsoft LLP64)

sizeof(short) is 2
sizeof(int) is 4
sizeof(long) is 4
sizeof(long long) is 8
sizeof(void*) is 8

64-bit Windows (MinGW LLP64)

sizeof(short) is 2
sizeof(int) is 4
sizeof(long) is 4
sizeof(long long) is 8
sizeof(void*) is 8

32-bit Linux

sizeof(short) is 2
sizeof(int) is 4
sizeof(long) is 4
sizeof(long long) is 8
sizeof(void*) is 4

64-bit Linux (gcc LP64)

sizeof(short) is 2
sizeof(int) is 4
sizeof(long) is 8
sizeof(long long) is 8
sizeof(void*) is 8

32-bit macOS (Clang/gcc)

sizeof(short) is 2
sizeof(int) is 4
sizeof(long) is 4
sizeof(long long) is 8
sizeof(void*) is 4

64-bit macOS (Clang/gcc LP64)

sizeof(short) is 2
sizeof(int) is 4
sizeof(long) is 8
sizeof(long long) is 8
sizeof(void*) is 8