1 /* PR tree-optimization/47538 */
2
3 struct S
4 {
5 double a, b, *c;
6 unsigned long d;
7 };
8
9 __attribute__((noinline, noclone)) void
foo(struct S * x,const struct S * y)10 foo (struct S *x, const struct S *y)
11 {
12 const unsigned long n = y->d + 1;
13 const double m = 0.25 * (y->b - y->a);
14 x->a = y->a;
15 x->b = y->b;
16 if (n == 1)
17 {
18 x->c[0] = 0.;
19 }
20 else if (n == 2)
21 {
22 x->c[1] = m * y->c[0];
23 x->c[0] = 2.0 * x->c[1];
24 }
25 else
26 {
27 double o = 0.0, p = 1.0;
28 unsigned long i;
29
30 for (i = 1; i <= n - 2; i++)
31 {
32 x->c[i] = m * (y->c[i - 1] - y->c[i + 1]) / (double) i;
33 o += p * x->c[i];
34 p = -p;
35 }
36 x->c[n - 1] = m * y->c[n - 2] / (n - 1.0);
37 o += p * x->c[n - 1];
38 x->c[0] = 2.0 * o;
39 }
40 }
41
42 int
main(void)43 main (void)
44 {
45 struct S x, y;
46 double c[4] = { 10, 20, 30, 40 }, d[4], e[4] = { 118, 118, 118, 118 };
47
48 y.a = 10;
49 y.b = 6;
50 y.c = c;
51 x.c = d;
52 y.d = 3;
53 __builtin_memcpy (d, e, sizeof d);
54 foo (&x, &y);
55 if (d[0] != 0 || d[1] != 20 || d[2] != 10 || d[3] != -10)
56 __builtin_abort ();
57 y.d = 2;
58 __builtin_memcpy (d, e, sizeof d);
59 foo (&x, &y);
60 if (d[0] != 60 || d[1] != 20 || d[2] != -10 || d[3] != 118)
61 __builtin_abort ();
62 y.d = 1;
63 __builtin_memcpy (d, e, sizeof d);
64 foo (&x, &y);
65 if (d[0] != -20 || d[1] != -10 || d[2] != 118 || d[3] != 118)
66 __builtin_abort ();
67 y.d = 0;
68 __builtin_memcpy (d, e, sizeof d);
69 foo (&x, &y);
70 if (d[0] != 0 || d[1] != 118 || d[2] != 118 || d[3] != 118)
71 __builtin_abort ();
72 return 0;
73 }
74