gcc/testsuite/gcc.dg/loop-unswitch-14.c

   1 /* { dg-do compile } */
   2 /* { dg-options "-O2 -funswitch-loops -fdump-tree-unswitch-optimized --param=max-unswitch-insns=1000" } */
   3 /* { dg-require-effective-target size32plus } */
   4
   5 int
   6 __attribute__((noipa))
   7 foo(double *a, double *b, double *c, double *d, double *r, int size, int order)
   8 {
   9   for (int i = 0; i < size; i++)
  10   {
  11     double tmp, tmp2;
  12
  13     if (order <= 0)
  14       tmp = 123;
  15
  16     switch(order)
  17     {
  18       case 0:
  19         tmp += -8 * a[i];
  20         tmp2 = 2 * b[i];
  21         break;
  22       case 1:
  23         tmp = 3 * a[i] -  2 * b[i];
  24         tmp2 = 5 * b[i] - 2 * c[i];
  25         break;
  26       case 2:
  27         tmp = 9 * a[i] +  2 * b[i] + c[i];
  28         tmp2 = 4 * b[i] + 2 * c[i] + 8 * d[i];
  29         break;
  30       case 3:
  31         tmp = 3 * a[i] +  2 * b[i] - c[i];
  32         tmp2 = b[i] - 2 * c[i] + 8 * d[i];
  33         break;
  34       default:
  35         __builtin_unreachable ();
  36     }
  37
  38     double x = 3 * tmp + d[i] + tmp;
  39     double y = 3.4f * tmp + d[i] + tmp2;
  40     r[i] = x + y;
  41   }
  42
  43   return 0;
  44 }
  45
  46 #define N 16 * 1024
  47 double aa[N], bb[N], cc[N], dd[N], rr[N];
  48
  49 int main()
  50 {
  51   for (int i = 0; i < 100 * 1000; i++)
  52     foo (aa, bb, cc, dd, rr, N, i % 4);
  53 }
  54
  55
  56 /* Test that we actually unswitched something.  */
  57 /* { dg-final { scan-tree-dump-times "unswitching loop . on .switch. with condition: order.* <= 0" 1 "unswitch" } } */
  58 /* { dg-final { scan-tree-dump-times "unswitching loop . on .switch. with condition: order.* == 0" 1 "unswitch" } } */
  59 /* { dg-final { scan-tree-dump-times "unswitching loop . on .switch. with condition: order.* == 1" 1 "unswitch" } } */
  60 /* { dg-final { scan-tree-dump-times "unswitching loop . on .switch. with condition: order.* == 2" 1 "unswitch" } } */
  61 /* { dg-final { scan-tree-dump-times "unswitching loop . on .switch. with condition: order.* == 3" 1 "unswitch" } } */