modernc.org/cc@v1.0.1/testdata/gcc-6.3.0/gcc/testsuite/gcc.c-torture/execute/builtins/lib/mempcpy.c (about)

     1  extern void abort (void);
     2  extern int inside_main;
     3  
     4  __attribute__ ((__noinline__))
     5  void *
     6  mempcpy (void *dst, const void *src, __SIZE_TYPE__ n)
     7  {
     8    const char *srcp;
     9    char *dstp;
    10  
    11  #ifdef __OPTIMIZE__
    12    if (inside_main)
    13      abort ();
    14  #endif
    15  
    16    srcp = src;
    17    dstp = dst;
    18    while (n-- != 0)
    19      *dstp++ = *srcp++;
    20  
    21    return dstp;
    22  }