1  /* PR tree-optimization/83821 - local aggregate initialization defeats
       2     strlen optimization
       3     Verify that a strlen() call is eliminated for a pointer to a region
       4     of memory allocated by calloc() even if one or more nul bytes are
       5     written into it.
       6     { dg-do compile }
       7     { dg-options "-O2 -fno-tree-vectorize -fdump-tree-optimized" } */
       8  
       9  unsigned n0, n1;
      10  
      11  void* elim_strlen_calloc_store_memset_1 (unsigned a, unsigned b)
      12  {
      13    char *p = __builtin_calloc (a, 1);
      14  
      15    p[0] = '\0';
      16    p[1] = '\0';
      17    p[2] = '\0';
      18    p[3] = '\0';
      19  
      20    __builtin_memset (p, 0, b);
      21  
      22    n0 = __builtin_strlen (p);
      23  
      24    return p;
      25  }
      26  
      27  void* elim_strlen_calloc_store_memset_2 (unsigned a, unsigned b, unsigned c)
      28  {
      29    char *p = __builtin_calloc (a, 1);
      30  
      31    p[1] = '\0';
      32    __builtin_memset (p, 0, b);
      33  
      34    n0 = __builtin_strlen (p);
      35  
      36    p[3] = 0;
      37    __builtin_memset (p, 0, c);
      38  
      39    n1 = __builtin_strlen (p);
      40  
      41    return p;
      42  }
      43  
      44  /* { dg-final { scan-tree-dump-not "__builtin_strlen" "optimized" } } */