modernc.org/ccgo/v3@v3.16.14/lib/testdata/gcc-9.1.0/gcc/testsuite/gcc.c-torture/compile/irreducible-loop.c (about)

     1  void foo (int n, double a, double *b, double *x)
     2  {
     3    int i, j;
     4  
     5    if(n <= 0) return;
     6    if (a == 0.0e0) return;
     7  
     8    if (a > 5.0)
     9      {
    10        i = 0;
    11        goto sec;
    12      }
    13    for (i = 0; i < 1024; i++)
    14      {
    15        double y = b[i];
    16  sec:
    17        b[i+1] = y + 5.0;
    18        for (j = 0; j < n; j++)
    19  	x[j] = x[j] + a;
    20      }
    21  }