[Beignet] [PATCH] add the reduced self loop node detection.

[xionghu.luo at intel.com]

From: Luo Xionghu <xionghu.luo at intel.com>

if the self loop node is reduced, the llvm loop info couldn't detect
such kind of self loops, handle it by checking whether the compacted
node has a successor pointed to itself.

Signed-off-by: Luo Xionghu <xionghu.luo at intel.com>
---
 backend/src/ir/structural_analysis.cpp |    9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/backend/src/ir/structural_analysis.cpp b/backend/src/ir/structural_analysis.cpp
index 21c04f3..a9d21ce 100644
--- a/backend/src/ir/structural_analysis.cpp
+++ b/backend/src/ir/structural_analysis.cpp
@@ -1038,6 +1038,15 @@ namespace analysis
             }
           }
 
+          if(reachUnder.size() == 0 )
+          {
+            if(n->succs().find(n) != n->succs().end())
+            {
+                reachUnder.push_front(n);
+                nset.insert(n);
+            }
+          }
+
           region = cyclicRegionType(n, reachUnder);
 
           if(NULL != region)
-- 
1.7.9.5