#include <stdio.h>
#include <string.h>
#pragma reverse_bitfields on
typedef struct
{
union
{
unsigned int i1;
#pragma pack(2)
struct
{
int b1: 1;
unsigned int b2: 2;
unsigned int b3: 4;
unsigned int b4: 8;
int b5: 16;
} bits;
} u1;
short baz;
union
{
struct
{
unsigned int i2;
unsigned int i3;
unsigned int i4;
unsigned int i5;
} ints;
#pragma pack(1)
struct
{
unsigned int b1: 16;
unsigned int b2: 8;
unsigned int b3: 4;
char quux;
unsigned int b4: 2;
unsigned int b5: 1;
short baz;
unsigned int b6: 2;
unsigned int b7: 4;
short baz2;
unsigned int b8: 8;
unsigned int b9: 16;
} bits;
} u2;
} Bitfields;
int main()
{
Bitfields bitfields;
memset(&bitfields, 0, sizeof(bitfields));
bitfields.u1.bits.b1 = 1;
bitfields.u1.bits.b2 = 1;
bitfields.u1.bits.b3 = 1;
bitfields.u1.bits.b4 = 1;
bitfields.u1.bits.b5 = 1;
bitfields.baz = 0x5555;
bitfields.u2.bits.b1 = 1;
bitfields.u2.bits.b2 = 1;
bitfields.u2.bits.b3 = 1;
bitfields.u2.bits.quux = 0xa55a;
bitfields.u2.bits.b4 = 1;
bitfields.u2.bits.b5 = 1;
bitfields.u2.bits.baz = 0xaaaa;
bitfields.u2.bits.b6 = 1;
bitfields.u2.bits.b7 = 1;
bitfields.u2.bits.baz2 = 0x3333;
bitfields.u2.bits.b8 = 1;
bitfields.u2.bits.b9 = 1;
if (bitfields.u1.i1 != 0x0000808b
|| bitfields.baz != 0x5555
|| bitfields.u2.ints.i2 != 0x01010001
|| bitfields.u2.ints.i3 != 0x5a00aaaa
|| bitfields.u2.ints.i4 != 0x01333305
|| bitfields.u2.ints.i5 != 0x00000001
|| sizeof(bitfields) != 22)
return 42;
return 0;
}