Comment fixes to MemorySSA.h

llvm-svn: 277308

llvm/include/llvm/Transforms/Utils/MemorySSA.h

@@ -534,7 +534,9 @@ public:
     return It == PerBlockAccesses.end() ? nullptr : It->second.get();
   }
 
-  /// \brief Create an empty MemoryPhi in MemorySSA
+  /// \brief Create an empty MemoryPhi in MemorySSA for a given basic block.
+  /// Only one MemoryPhi for a block exists at a time, so this function will
+  /// assert if you try to create one where it already exists.
   MemoryPhi *createMemoryPhi(BasicBlock *BB);
 
   enum InsertionPlace { Beginning, End };

llvm/unittests/Transforms/Utils/MemorySSA.cpp

@@ -67,7 +67,7 @@ public:
 
 TEST_F(MemorySSATest, CreateALoadAndPhi) {
   // We create a diamond where there is a store on one side, and then after
-  // running memory ssa, create a load after the merge point, and use it to test
+  // building MemorySSA, create a load after the merge point, and use it to test
   // updating by creating an access for the load and a memoryphi.
   F = Function::Create(
       FunctionType::get(B.getVoidTy(), {B.getInt8PtrTy()}, false),