diff --git a/lib/Support/raw_ostream.cpp b/lib/Support/raw_ostream.cpp
index b8a1537ae8a..d156826144a 100644
--- a/lib/Support/raw_ostream.cpp
+++ b/lib/Support/raw_ostream.cpp
@@ -729,26 +729,17 @@ void raw_svector_ostream::resync() {
 }
 
 void raw_svector_ostream::write_impl(const char *Ptr, size_t Size) {
-  size_t NewSize = OS.size() + Size;
-  size_t NewReservation = NewSize + 64;
-
-  bool NoOverlap = Ptr + Size < OS.begin() || Ptr > OS.begin() + OS.capacity();
-
-  if (NoOverlap) {
-    assert(!GetNumBytesInBuffer());
-    OS.reserve(NewReservation);
-    memcpy(OS.end(), Ptr, Size);
-    OS.set_size(NewSize);
-  } else if (Ptr == OS.end()) {
+  if (Ptr == OS.end()) {
     // Grow the buffer to include the scratch area without copying.
+    size_t NewSize = OS.size() + Size;
     assert(NewSize <= OS.capacity() && "Invalid write_impl() call!");
     OS.set_size(NewSize);
-    OS.reserve(NewReservation);
   } else {
+    assert(!GetNumBytesInBuffer());
     OS.append(Ptr, Ptr + Size);
-    OS.reserve(NewReservation);
   }
 
+  OS.reserve(OS.size() + 64);
   SetBuffer(OS.end(), OS.capacity() - OS.size());
 }