diff --git a/include/llvm/ADT/SmallVector.h b/include/llvm/ADT/SmallVector.h
index 791d03c6491..df46f919118 100644
--- a/include/llvm/ADT/SmallVector.h
+++ b/include/llvm/ADT/SmallVector.h
@@ -223,14 +223,14 @@ protected:
 
 public:
   void push_back(const T &Elt) {
-    if (this->EndX >= this->CapacityX)
+    if (LLVM_UNLIKELY(this->EndX >= this->CapacityX))
       this->grow();
     ::new ((void*) this->end()) T(Elt);
     this->setEnd(this->end()+1);
   }
 
   void push_back(T &&Elt) {
-    if (this->EndX >= this->CapacityX)
+    if (LLVM_UNLIKELY(this->EndX >= this->CapacityX))
       this->grow();
     ::new ((void*) this->end()) T(::std::move(Elt));
     this->setEnd(this->end()+1);
@@ -327,7 +327,7 @@ protected:
   }
 public:
   void push_back(const T &Elt) {
-    if (this->EndX >= this->CapacityX)
+    if (LLVM_UNLIKELY(this->EndX >= this->CapacityX))
       this->grow();
     memcpy(this->end(), &Elt, sizeof(T));
     this->setEnd(this->end()+1);