modernc.org/ccgo/v3@v3.16.14/lib/testdata/gcc-9.1.0/gcc/testsuite/gcc.c-torture/execute/991016-1.c (about)

     1  /* Two of these types will, on current gcc targets, have the same
     2     mode but have different alias sets.  DOIT tries to get gcse to
     3     invalidly hoist one of the values out of the loop.  */
     4  
     5  typedef int T0;
     6  typedef long T1;
     7  typedef long long T2;
     8  
     9  int
    10  doit(int sel, int n, void *p)
    11  {
    12    T0 * const p0 = p;
    13    T1 * const p1 = p;
    14    T2 * const p2 = p;
    15  
    16    switch (sel)
    17      {
    18      case 0:
    19        do 
    20  	*p0 += *p0;
    21        while (--n);
    22        return *p0 == 0;
    23  
    24      case 1:
    25        do 
    26  	*p1 += *p1;
    27        while (--n);
    28        return *p1 == 0;
    29  
    30      case 2:
    31        do 
    32  	*p2 += *p2;
    33        while (--n);
    34        return *p2 == 0;
    35  
    36      default:
    37        abort ();
    38      }
    39  }
    40  
    41  int
    42  main()
    43  {
    44    T0 v0; T1 v1; T2 v2;
    45  
    46    v0 = 1; doit(0, 5, &v0);
    47    v1 = 1; doit(1, 5, &v1);
    48    v2 = 1; doit(2, 5, &v2);
    49  
    50    if (v0 != 32) abort ();
    51    if (v1 != 32) abort ();
    52    if (v2 != 32) abort ();
    53  
    54    exit (0);
    55  }