1 files changed, 35 insertions, 0 deletions
diff --git a/gcc/testsuite/gcc.dg/tree-ssa-chrec/ssa-chrec-36.c b/gcc/testsuite/gcc.dg/tree-ssa-chrec/ssa-chrec-36.c
new file mode 100644
index 00000000000..916c81548c8
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa-chrec/ssa-chrec-36.c
@@ -0,0 +1,35 @@
+/* { dg-do compile } */ 
+/* { dg-options "-O1 -fscalar-evolutions -fdump-tree-scev-details -fall-data-deps -fdump-tree-ddall" } */
+
+int foo (int);
+
+int main ()
+{
+  int res;
+  int c[100][200];
+  int a;
+  int x;
+  
+  for (a = 1; a < 50; a++)
+    {
+      c[a+1][a] = 2;
+      res += c[a][a];
+      
+      /* This case exercises the subscript coupling detection: the dependence
+	 detectors have to determine that there is no dependence between 
+	 c[a+1][a] and c[a][a].  */
+    }
+  
+  return res + foo (c[12][13]);
+}
+
+/* This also exercises the case when, after a PRE, the loop phi node contains:
+   "  #   a_1 = PHI <1(0), T.1_11(1)>;
+   ...
+   T.1_11 = a_1 + 1;". 
+   In fact this creates a cycle:  a -> T.1 -> a.
+   The PRE has screwed up the case...
+   ...I really have to implement the mixers analyzers.  */
+
+/* { dg-final { diff-tree-dumps "ddall" } } */
+