Add new RegionInfo pass.
The RegionInfo pass detects single entry single exit regions in a function,
where a region is defined as any subgraph that is connected to the remaining
graph at only two spots.
Furthermore an hierarchical region tree is built.
Use it by calling "opt -regions analyze" or "opt -view-regions".
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@109089 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Analysis/RegionInfo/nested_loops.ll b/test/Analysis/RegionInfo/nested_loops.ll
new file mode 100644
index 0000000..9d8c455
--- /dev/null
+++ b/test/Analysis/RegionInfo/nested_loops.ll
@@ -0,0 +1,33 @@
+; RUN: opt -regions -analyze < %s | FileCheck %s
+; RUN: opt -regions -stats < %s |& FileCheck -check-prefix=STAT %s
+
+; RUN: opt -regions -print-region-style=bb -analyze < %s |& FileCheck -check-prefix=BBIT %s
+; RUN: opt -regions -print-region-style=rn -analyze < %s |& FileCheck -check-prefix=RNIT %s
+
+define internal fastcc zeroext i8 @handle_compress() nounwind {
+entry:
+ br label %outer
+
+outer:
+ br label %body
+
+body:
+ br i1 1, label %exit172, label %end
+
+exit172:
+ br i1 1, label %end, label %outer
+
+end:
+ ret i8 1
+}
+; CHECK-NOT: =>
+; CHECK: [0] entry => <Function Return>
+; CHECK-NEXT: [1] outer => end
+
+; STAT: 2 region - The # of regions
+
+; BBIT: entry, outer, body, exit172, end,
+; BBIT: outer, body, exit172,
+
+; RNIT: entry, outer => end, end,
+; RNIT: outer, body, exit172,