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".

llvm-svn: 109089

1 files changed, 33 insertions, 0 deletions

diff --git a/llvm/test/Analysis/RegionInfo/cond_loop.ll b/llvm/test/Analysis/RegionInfo/cond_loop.ll
new file mode 100644
index 00000000000..2ce57c3c5f3
--- /dev/null
+++ b/llvm/test/Analysis/RegionInfo/cond_loop.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 void @normal_condition() nounwind {
+5:
+        br label %"0"
+
+0:
+	br label %"1"
+1:
+	br i1 1, label %"2", label %"3"
+2:
+	ret void
+3:
+	br i1 1, label %"1", label %"4"
+4:
+        br label %"0"
+}
+
+; CHECK-NOT: =>
+; CHECK: [0] 5 => <Function Return>
+; CHECK: [1] 0 => 2
+
+; STAT: 2 region - The # of regions
+; STAT: 1 region - The # of simple regions
+
+; BBIT: 5, 0, 1, 2, 3, 4,
+; BBIT: 0, 1, 3, 4,
+
+; RNIT: 5, 0 => 2, 2,
+; RNIT: 0, 1, 3, 4,