gcc/testsuite/gcc.dg/tree-ssa/ldist-3.c

   1 /* { dg-do compile } */
   2 /* { dg-options "-O2 -ftree-loop-distribution -fdump-tree-ldist-all" } */
   3
   4 int loop1 (int k)
   5 {
   6   unsigned int i;
   7   int a[10000], b[10000], c[10000], d[10000];
   8
   9   a[0] = k; a[3] = k*2;
  10   c[1] = k+1;
  11   for (i = 2; i < (10000-1); i ++)
  12     {
  13       a[i] = k * i; /* S1 */
  14       b[i] = a[i-2] + k; /* S2 */
  15       c[i] = b[i] + a[i+1]; /* S3 */
  16       d[i] = c[i-1] + k + i; /* S4 */
  17     }
  18   /*
  19     Dependences:
  20     S1 -> S2 (flow, level 1)
  21     S1 -> S3 (anti, level 1)
  22     S2 -> S3 (flow, level 0)
  23     S3 -> S4 (flow, level 1)
  24
  25     There are three partitions: {S1, S3}, {S2} and {S4}.
  26
  27     The cost model should fuse together all the partitions, as they
  28     are reusing the same data, ending on a single partition.
  29   */
  30   return a[10000-2] + b[10000-1] + c[10000-2] + d[10000-2];
  31 }
  32
  33 /* { dg-final { scan-tree-dump-times "distributed: split to 3 loops" 0 "ldist" } } */
  34 /* { dg-final { cleanup-tree-dump "ldist" } } */