modernc.org/ccgo/v3@v3.16.14/lib/testdata/gcc-9.1.0/gcc/testsuite/gcc.c-torture/execute/pr65215-5.c (about)

     1  /* PR tree-optimization/65215 */
     2  
     3  __attribute__((noinline, noclone)) unsigned int
     4  foo (unsigned char *p)
     5  {
     6    return ((unsigned int) p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3];
     7  }
     8  
     9  __attribute__((noinline, noclone)) unsigned int
    10  bar (unsigned char *p)
    11  {
    12    return ((unsigned int) p[3] << 24) | (p[2] << 16) | (p[1] << 8) | p[0];
    13  }
    14  
    15  struct S { unsigned int a; unsigned char b[5]; };
    16  
    17  int
    18  main ()
    19  {
    20    struct S s = { 1, { 2, 3, 4, 5, 6 } };
    21    if (__CHAR_BIT__ != 8 || sizeof (unsigned int) != 4)
    22      return 0;
    23    if (foo (&s.b[1]) != 0x03040506U
    24        || bar (&s.b[1]) != 0x06050403U)
    25      __builtin_abort ();
    26    return 0;
    27  }