1 files changed, 38 insertions, 0 deletions
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ldist-6.c b/gcc/testsuite/gcc.dg/tree-ssa/ldist-6.c
new file mode 100644
index 000000000..7a38c8683
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/ldist-6.c
@@ -0,0 +1,38 @@
+/* { dg-do compile } */ 
+/* { dg-options "-O2 -ftree-loop-distribution -fdump-tree-ldist-all" } */
+
+int loop1 (int k)
+{
+  unsigned int i;
+  int a[1000], b[1000], c[1000], d[1000];
+
+  for (i = 2; i < (1000-1); i ++) {
+    a[i] = k * i; /* S1 */
+    b[i] = a[i-2] + k; /* S2 */
+    c[i] = b[i-1] + a[i+1]; /* S3 */
+    d[i] = c[i-1] + k + i; /* S4 */
+  }
+  /* Dependences:
+     S1->S2 (flow, level 1)
+     S2->S3 (flow, level 1)
+     S3->S1 (anti, level 1)
+     S3->S4 (flow, level 1)
+
+    There are two partitions: {S1, S2, S3} and {S4}.
+
+    {S1, S2, S3} have to be in the same partition because:
+    - S1 (i) has to be executed before S2 (i+2), as S1 produces a[i] that is then consumed 2 iterations later by S2.
+    - S2 (i) has to be executed before S3 (i+1), as S2 produces b[i] that is then consumed one iteration later by S3,
+    - S3 (i) has to be executed before S1 (i+1), as a[i+1] has to execute before the update to a[i],
+
+    {S4} is the consumer partition: it consumes the values from array "c" produced in S3.
+
+    The cost model should fuse all the tasks together as the cost of
+    fetching data from caches is too high.
+  */
+
+  return a[1000-2] + b[1000-1] + c[1000-2] + d[1000-2];
+}
+
+/* { dg-final { scan-tree-dump-times "distributed: split to 2 loops" 0 "ldist" } } */
+/* { dg-final { cleanup-tree-dump "ldist" } } */