1 /* { dg-do compile } */
2 /* { dg-do run } */
3 /* { dg-options "-O2 -funroll-loops --param max-unroll-times=8 -fpredictive-commoning -fdump-tree-pcom-details -fno-tree-pre" } */
4 
5 void abort (void);
6 
7 unsigned fib[1000];
8 
9 __attribute__ ((noinline))
count_fib(void)10 void count_fib(void)
11 {
12   int i;
13 
14   fib[0] = 0;
15   fib[1] = 1;
16   for (i = 2; i < 1000; i++)
17     fib[i] = (fib[i-1] + fib[i - 2]) & 0xffff;
18 }
19 
20 unsigned avg[1000];
21 
22 __attribute__ ((noinline))
count_averages(int n)23 void count_averages(int n)
24 {
25   int i;
26 
27   for (i = 1; i < n; i++)
28     avg[i] = (((unsigned long) fib[i - 1] + fib[i] + fib[i + 1]) / 3) & 0xffff;
29 }
30 
main(void)31 int main(void)
32 {
33   count_fib ();
34   count_averages (999);
35 
36   if (fib[19] != 4181 || avg[19] != 4510)
37     abort ();
38 
39   if (fib[999] != 162 || avg[998] != 21953)
40     abort ();
41 
42   return 0;
43 }
44 
45 /* Verify that both loops were transformed and unrolled.  */
46 /* { dg-final { scan-tree-dump-times "Unrolling 2 times." 2 "pcom"} } */
47 
48 /* Also check that we undid the transformation previously made by PRE.
49    ???  PRE now does the predictive commoning in count_averages.  */
50 /* dg-final { scan-tree-dump-times "looparound ref" 1 "pcom" } */
51