modernc.org/ccgo/v3@v3.16.14/lib/testdata/gcc-9.1.0/gcc/testsuite/gcc.c-torture/execute/memcpy-2.c (about)

     1  /* Copyright (C) 2002  Free Software Foundation.
     2  
     3     Test memcpy with various combinations of pointer alignments and lengths to
     4     make sure any optimizations in the library are correct.
     5  
     6     Written by Michael Meissner, March 9, 2002.  */
     7  
     8  #include <string.h>
     9  
    10  #ifndef MAX_OFFSET
    11  #define MAX_OFFSET (sizeof (long long))
    12  #endif
    13  
    14  #ifndef MAX_COPY
    15  #define MAX_COPY (10 * sizeof (long long))
    16  #endif
    17  
    18  #ifndef MAX_EXTRA
    19  #define MAX_EXTRA (sizeof (long long))
    20  #endif
    21  
    22  #define MAX_LENGTH (MAX_OFFSET + MAX_COPY + MAX_EXTRA)
    23  
    24  
    25  /* Use a sequence length that is not divisible by two, to make it more
    26     likely to detect when words are mixed up.  */
    27  #define SEQUENCE_LENGTH 31
    28  
    29  static union {
    30    char buf[MAX_LENGTH];
    31    long long align_int;
    32    long double align_fp;
    33  } u1, u2;
    34  
    35  main ()
    36  {
    37    int off1, off2, len, i;
    38    char *p, *q, c;
    39  
    40    for (off1 = 0; off1 < MAX_OFFSET; off1++)
    41      for (off2 = 0; off2 < MAX_OFFSET; off2++)
    42        for (len = 1; len < MAX_COPY; len++)
    43  	{
    44  	  for (i = 0, c = 'A'; i < MAX_LENGTH; i++, c++)
    45  	    {
    46  	      u1.buf[i] = 'a';
    47  	      if (c >= 'A' + SEQUENCE_LENGTH)
    48  		c = 'A';
    49  	      u2.buf[i] = c;
    50  	    }
    51  
    52  	  p = memcpy (u1.buf + off1, u2.buf + off2, len);
    53  	  if (p != u1.buf + off1)
    54  	    abort ();
    55  
    56  	  q = u1.buf;
    57  	  for (i = 0; i < off1; i++, q++)
    58  	    if (*q != 'a')
    59  	      abort ();
    60  
    61  	  for (i = 0, c = 'A' + off2; i < len; i++, q++, c++)
    62  	    {
    63  	      if (c >= 'A' + SEQUENCE_LENGTH)
    64  		c = 'A';
    65  	      if (*q != c)
    66  		abort ();
    67  	    }
    68  
    69  	  for (i = 0; i < MAX_EXTRA; i++, q++)
    70  	    if (*q != 'a')
    71  	      abort ();
    72  	}
    73  
    74    exit (0);
    75  }