Factor out the predicate code for loopsimplify form exit blocks into
a separate helper function.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86159 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/llvm/Analysis/LoopInfo.h b/include/llvm/Analysis/LoopInfo.h
index bc87adb..ac565c7 100644
--- a/include/llvm/Analysis/LoopInfo.h
+++ b/include/llvm/Analysis/LoopInfo.h
@@ -572,6 +572,10 @@
/// normal form.
bool isLoopSimplifyForm() const;
+ /// hasDedicatedExits - Return true if no exit block for the loop
+ /// has a predecessor that is outside the loop.
+ bool hasDedicatedExits() const;
+
/// getUniqueExitBlocks - Return all unique successor blocks of this loop.
/// These are the blocks _outside of the current loop_ which are branched to.
/// This assumes that loop is in canonical form.
diff --git a/lib/Analysis/LoopInfo.cpp b/lib/Analysis/LoopInfo.cpp
index e9256b7..b5f407d 100644
--- a/lib/Analysis/LoopInfo.cpp
+++ b/lib/Analysis/LoopInfo.cpp
@@ -286,12 +286,14 @@
/// the LoopSimplify form transforms loops to, which is sometimes called
/// normal form.
bool Loop::isLoopSimplifyForm() const {
- // Normal-form loops have a preheader.
- if (!getLoopPreheader())
- return false;
- // Normal-form loops have a single backedge.
- if (!getLoopLatch())
- return false;
+ // Normal-form loops have a preheader, a single backedge, and all of their
+ // exits have all their predecessors inside the loop.
+ return getLoopPreheader() && getLoopLatch() && hasDedicatedExits();
+}
+
+/// hasDedicatedExits - Return true if no exit block for the loop
+/// has a predecessor that is outside the loop.
+bool Loop::hasDedicatedExits() const {
// Sort the blocks vector so that we can use binary search to do quick
// lookups.
SmallPtrSet<BasicBlock *, 16> LoopBBs(block_begin(), block_end());