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

     1  /* Test for -fno-builtin-FUNCTION.  */
     2  /* Origin: Joseph Myers <jsm28@cam.ac.uk>.  */
     3  /* GCC normally handles abs and labs as built-in functions even without
     4     optimization.  So test that with -fno-builtin-abs, labs is so handled
     5     but abs isn't.  */
     6  
     7  int abs_called = 0;
     8  
     9  extern int abs (int);
    10  extern long labs (long);
    11  extern void abort (void);
    12  
    13  void
    14  main_test (void)
    15  {
    16    if (labs (0) != 0)
    17      abort ();
    18    if (abs (0) != 0)
    19      abort ();
    20    if (!abs_called)
    21      abort ();
    22  }