[Dominators] Add isUpdateLazy() method to the DomTreeUpdater

Summary:
Previously, when people need to deal with DTU with different UpdateStrategy using different actions, they need to
```
if (DTU.getUpdateStrategy() == DomTreeUpdater::UpdateStrategy::Lazy) {
  ...
}
if (DTU.getUpdateStrategy() == DomTreeUpdater::UpdateStrategy::Eager) {
  ...
}
```
After the patch, they can avoid code patterns above
```
if (DTU.isUpdateLazy()){
  ...
}
if (!DTU.isUpdateLazy()){
  ...
}
```

Reviewers: kuhar, brzycki, dmgreen

Reviewed By: kuhar

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D49056

llvm-svn: 336886

2 files changed, 19 insertions, 9 deletions

diff --git a/llvm/include/llvm/IR/DomTreeUpdater.h b/llvm/include/llvm/IR/DomTreeUpdater.h
index 6278dd5d870..089c8528794 100644
--- a/llvm/include/llvm/IR/DomTreeUpdater.h
+++ b/llvm/include/llvm/IR/DomTreeUpdater.h
@@ -46,8 +46,11 @@ public:
 
   ~DomTreeUpdater() { flush(); }
 
-  /// Returns the UpdateStrategy of the class instance.
-  UpdateStrategy getUpdateStrategy() const { return Strategy; };
+  /// Returns true if the current strategy is Lazy.
+  bool isLazy() const { return Strategy == UpdateStrategy::Lazy; };
+
+  /// Returns true if the current strategy is Eager.
+  bool isEager() const { return Strategy == UpdateStrategy::Eager; };
 
   /// Returns true if it holds a DominatorTree.
   bool hasDomTree() const { return DT != nullptr; }
diff --git a/llvm/unittests/IR/DomTreeUpdaterTest.cpp b/llvm/unittests/IR/DomTreeUpdaterTest.cpp
index 242eee7d09e..10d84442617 100644
--- a/llvm/unittests/IR/DomTreeUpdaterTest.cpp
+++ b/llvm/unittests/IR/DomTreeUpdaterTest.cpp
@@ -58,7 +58,8 @@ TEST(DomTreeUpdater, EagerUpdateBasicOperations) {
 
   ASSERT_TRUE(DTU.hasDomTree());
   ASSERT_TRUE(DTU.hasPostDomTree());
-  ASSERT_EQ(DTU.getUpdateStrategy(), DomTreeUpdater::UpdateStrategy::Eager);
+  ASSERT_TRUE(DTU.isEager());
+  ASSERT_FALSE(DTU.isLazy());
   ASSERT_TRUE(DTU.getDomTree().verify());
   ASSERT_TRUE(DTU.getPostDomTree().verify());
   ASSERT_FALSE(DTU.hasPendingUpdates());
@@ -166,7 +167,8 @@ TEST(DomTreeUpdater, EagerUpdateReplaceEntryBB) {
   DomTreeUpdater DTU(DT, PDT, DomTreeUpdater::UpdateStrategy::Eager);
   ASSERT_TRUE(DTU.hasDomTree());
   ASSERT_TRUE(DTU.hasPostDomTree());
-  ASSERT_EQ(DTU.getUpdateStrategy(), DomTreeUpdater::UpdateStrategy::Eager);
+  ASSERT_TRUE(DTU.isEager());
+  ASSERT_FALSE(DTU.isLazy());
   ASSERT_TRUE(DT.verify());
   ASSERT_TRUE(PDT.verify());
 
@@ -239,7 +241,8 @@ TEST(DomTreeUpdater, LazyUpdateDTBasicOperations) {
   DomTreeUpdater DTU(&DT, PDT, DomTreeUpdater::UpdateStrategy::Lazy);
   ASSERT_TRUE(DTU.hasDomTree());
   ASSERT_FALSE(DTU.hasPostDomTree());
-  ASSERT_EQ(DTU.getUpdateStrategy(), DomTreeUpdater::UpdateStrategy::Lazy);
+  ASSERT_FALSE(DTU.isEager());
+  ASSERT_TRUE(DTU.isLazy());
   ASSERT_TRUE(DTU.getDomTree().verify());
 
   Function::iterator FI = F->begin();
@@ -327,7 +330,8 @@ TEST(DomTreeUpdater, LazyUpdateDTInheritedPreds) {
   DomTreeUpdater DTU(&DT, PDT, DomTreeUpdater::UpdateStrategy::Lazy);
   ASSERT_TRUE(DTU.hasDomTree());
   ASSERT_FALSE(DTU.hasPostDomTree());
-  ASSERT_EQ(DTU.getUpdateStrategy(), DomTreeUpdater::UpdateStrategy::Lazy);
+  ASSERT_FALSE(DTU.isEager());
+  ASSERT_TRUE(DTU.isLazy());
   ASSERT_TRUE(DTU.getDomTree().verify());
 
   Function::iterator FI = F->begin();
@@ -453,7 +457,8 @@ TEST(DomTreeUpdater, LazyUpdateBasicOperations) {
   DomTreeUpdater DTU(&DT, &PDT, DomTreeUpdater::UpdateStrategy::Lazy);
   ASSERT_TRUE(DTU.hasDomTree());
   ASSERT_TRUE(DTU.hasPostDomTree());
-  ASSERT_EQ(DTU.getUpdateStrategy(), DomTreeUpdater::UpdateStrategy::Lazy);
+  ASSERT_FALSE(DTU.isEager());
+  ASSERT_TRUE(DTU.isLazy());
   ASSERT_TRUE(DTU.getDomTree().verify());
   ASSERT_TRUE(DTU.getPostDomTree().verify());
 
@@ -535,7 +540,8 @@ TEST(DomTreeUpdater, LazyUpdateReplaceEntryBB) {
   DomTreeUpdater DTU(DT, PDT, DomTreeUpdater::UpdateStrategy::Lazy);
   ASSERT_TRUE(DTU.hasDomTree());
   ASSERT_TRUE(DTU.hasPostDomTree());
-  ASSERT_EQ(DTU.getUpdateStrategy(), DomTreeUpdater::UpdateStrategy::Lazy);
+  ASSERT_FALSE(DTU.isEager());
+  ASSERT_TRUE(DTU.isLazy());
   ASSERT_TRUE(DTU.getDomTree().verify());
   ASSERT_TRUE(DTU.getPostDomTree().verify());
 
@@ -624,7 +630,8 @@ TEST(DomTreeUpdater, LazyUpdateStepTest) {
 
   ASSERT_TRUE(DTU.hasDomTree());
   ASSERT_TRUE(DTU.hasPostDomTree());
-  ASSERT_EQ(DTU.getUpdateStrategy(), DomTreeUpdater::UpdateStrategy::Lazy);
+  ASSERT_FALSE(DTU.isEager());
+  ASSERT_TRUE(DTU.isLazy());
   ASSERT_TRUE(DTU.getDomTree().verify());
   ASSERT_TRUE(DTU.getPostDomTree().verify());
   ASSERT_FALSE(DTU.hasPendingUpdates());