llvm/clang/test/CodeGen/2007-04-05-PackedBitFields.c

// RUN: %clang_cc1 %s -emit-llvm -o -

# define pck __attribute__((packed))


struct pck E { 
  unsigned long long l, 
    i : 12, 
    j : 23, 
    k : 29; };

struct E e1;

void foo(void) {
	e1.k = 5;
}