gcc/testsuite/gcc.dg/tree-ssa/tailrecursion-5.c

   1 /* { dg-do run } */
   2 /* { dg-options "-O1 -foptimize-sibling-calls -fdump-tree-optimized" } */
   3
   4 extern void abort (void);
   5 extern void exit (int);
   6
   7 int sum (int n)
   8 {
   9   if (n == 0)
  10     return 0;
  11
  12   return n + sum (n - 1);
  13 }
  14
  15 int fac (int n)
  16 {
  17   if (n == 0)
  18     return 1;
  19
  20   return n * fac (n - 1);
  21 }
  22
  23 int sq_sum (int n)
  24 {
  25   if (n == 0)
  26     return 0;
  27
  28   return n * n + sq_sum (n - 1);
  29 }
  30
  31 int pow2m1 (int n)
  32 {
  33   if (n == 0)
  34     return 0;
  35
  36   return 2 * pow2m1 (n - 1) + 1;
  37 }
  38
  39 int fib (int n)
  40 {
  41   if (n <= 1)
  42     return 1;
  43
  44   return fib (n - 2) + fib (n - 1);
  45 }
  46
  47 int main(void)
  48 {
  49   if (sum (5) != 15)
  50     abort ();
  51
  52   if (fac (5) != 120)
  53     abort ();
  54
  55   if (sq_sum (5) != 55)
  56     abort ();
  57
  58   if (pow2m1 (5) != 31)
  59     abort ();
  60
  61   if (fib (5) != 8)
  62     abort ();
  63
  64   exit (0);
  65 }
  66
  67 /* There is one call of sum in main and then 2 instances of the word in
  68    ;; Function sum (sum) and one in the function header.  */
  69 /* { dg-final { scan-tree-dump-times "\\msum\\M" 4 "optimized"} } */
  70 /* { dg-final { scan-tree-dump-times "\\mfac\\M" 4 "optimized"} } */
  71 /* { dg-final { scan-tree-dump-times "\\msq_sum\\M" 4 "optimized"} } */
  72 /* { dg-final { scan-tree-dump-times "\\mpow2m1\\M" 4 "optimized"} } */
  73
  74 /* There is one recursive call to fib.  */
  75 /* { dg-final { scan-tree-dump-times "\\mfib\\M" 5 "optimized"} } */
  76
  77 /* { dg-final { cleanup-tree-dump "optimized" } } */