diff --git a/cmake/modules/HandleLLVMOptions.cmake b/cmake/modules/HandleLLVMOptions.cmake
index 1aadd61c602..7a6f63319fb 100644
--- a/cmake/modules/HandleLLVMOptions.cmake
+++ b/cmake/modules/HandleLLVMOptions.cmake
@@ -247,6 +247,12 @@ if( MSVC_IDE )
 endif()
 
 if( MSVC )
+  if( CMAKE_CXX_COMPILER_VERSION VERSION_LESS 19.0 )
+    # For MSVC 2013, disable iterator null pointer checking in debug mode,
+    # especially so std::equal(nullptr, nullptr, nullptr) will not assert.
+    add_llvm_definitions("-D_DEBUG_POINTER_IMPL=")
+  endif()
+  
   include(ChooseMSVCCRT)
 
   if( NOT (${CMAKE_VERSION} VERSION_LESS 2.8.11) )
diff --git a/docs/CodingStandards.rst b/docs/CodingStandards.rst
index f410293e1bf..91faadffea6 100644
--- a/docs/CodingStandards.rst
+++ b/docs/CodingStandards.rst
@@ -178,8 +178,6 @@ being aware of:
 * While most of the atomics library is well implemented, the fences are
   missing. Fortunately, they are rarely needed.
 * The locale support is incomplete.
-* ``std::equal()`` (and other algorithms) incorrectly assert in MSVC when given
-  ``nullptr`` as an iterator.
 
 Other than these areas you should assume the standard library is available and
 working as expected until some build bot tells you otherwise. If you're in an
diff --git a/include/llvm/ADT/ArrayRef.h b/include/llvm/ADT/ArrayRef.h
index e8063305591..c28fdffae73 100644
--- a/include/llvm/ADT/ArrayRef.h
+++ b/include/llvm/ADT/ArrayRef.h
@@ -156,8 +156,6 @@ namespace llvm {
     bool equals(ArrayRef RHS) const {
       if (Length != RHS.Length)
         return false;
-      if (Length == 0)
-        return true;
       return std::equal(begin(), end(), RHS.begin());
     }
 
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 0ae52b2caf0..0d73bc5e65d 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -5676,7 +5676,7 @@ UpdateNodeOperands(SDNode *N, ArrayRef<SDValue> Ops) {
          "Update with wrong number of operands");
 
   // If no operands changed just return the input node.
-  if (Ops.empty() || std::equal(Ops.begin(), Ops.end(), N->op_begin()))
+  if (std::equal(Ops.begin(), Ops.end(), N->op_begin()))
     return N;
 
   // See if the modified node already exists.