gcc/testsuite/gcc.dg/tree-ssa/predcom-2.c

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