1  /* { dg-do run } */
       2  /* { dg-options "-O2" } */
       3  
       4  /* PR target/20126 was not really target-specific, but rather a loop's
       5     failure to take into account the possibility that a DEST_ADDR giv
       6     replacement might fail, such as when you attempt to replace a REG
       7     with a PLUS in one of the register_operands of cmpstrqi_rex_1.  */
       8  
       9  extern void abort (void);
      10  
      11  typedef struct { int a; char b[3]; } S;
      12  S c = { 2, "aa" }, d = { 2, "aa" };
      13  
      14  void *
      15  bar (const void *x, int y, int z)
      16  {
      17    return (void *) 0;
      18  }
      19  
      20  int
      21  foo (S *x, S *y)
      22  {
      23    const char *e, *f, *g;
      24    int h;
      25  
      26    h = y->a;
      27    f = y->b;
      28    e = x->b;
      29  
      30    if (h == 1)
      31      return bar (e, *f, x->a) != 0;
      32  
      33    g = e + x->a - h;
      34    while (e <= g)
      35      {
      36        const char *t = e + 1;
      37        /* The pointer E below increases but the bound H stays constant,
      38  	 letting the latter exceed the size remaining in the argument
      39  	 pointed to by the formed, which might be detected by
      40  	 -Wstringop-overread.  */
      41        if (__builtin_memcmp (e, f, h) == 0)
      42          return 1;
      43        e = t;
      44      }
      45    return 0;
      46  }
      47  
      48  int
      49  main (void)
      50  {
      51    if (foo (&c, &d) != 1)
      52      abort ();
      53    return 0;
      54  }
      55  
      56  /* { dg-prune-output "-Wstringop-overread" } */