gcc/testsuite/gcc.dg/tree-ssa/ldist-7.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, z;
   7   int a[1000], b[1000], c[1000], d[1000];
   8
   9   for (i = 2; i < (1000-1); i ++) {
  10     z = a[i+1]; /* S1 */
  11     a[i] = k * i; /* S2 */
  12     b[i] = a[i-2] + k; /* S3 */
  13     c[i] = b[i-1] + z; /* S4 */
  14     d[i] = c[i-1] + b[i+1] + k + i; /* S5 */
  15   }
  16   /* Dependences:
  17      S1->S2 (anti, level 1)
  18      S1->S4 (flow, level 1, scalar)
  19      S2->S3 (flow, level 1)
  20      S3->S4 (flow, level 1)
  21      S4->S5 (flow, level 1)
  22      S5->S3 (anti, level 1)
  23
  24      There is a single partition: {S1, S2, S3, S4, S5}, because of the
  25      scalar dependence z between the two partitions {S1, S2} and {S3, S4, S5}.
  26   */
  27
  28   return a[1000-2] + b[1000-1] + c[1000-2] + d[1000-2];
  29 }
  30
  31 /* { dg-final { scan-tree-dump-times "distributed: " 0 "ldist" } } */