Index: llvm/include/llvm/ADT/STLExtras.h
===================================================================
--- llvm/include/llvm/ADT/STLExtras.h
+++ llvm/include/llvm/ADT/STLExtras.h
@@ -1796,6 +1796,11 @@
          std::equal(adl_begin(Range) + 1, adl_end(Range), adl_begin(Range)));
 }
 
+/// Returns true iff all Values in the initializer lists are same.
+template <typename T> bool is_splat(std::initializer_list<T> Values) {
+  return is_splat<std::initializer_list<T>>(std::move(Values));
+}
+
 /// Provide a container algorithm similar to C++ Library Fundamentals v2's
 /// `erase_if` which is equivalent to:
 ///
Index: llvm/unittests/ADT/STLExtrasTest.cpp
===================================================================
--- llvm/unittests/ADT/STLExtrasTest.cpp
+++ llvm/unittests/ADT/STLExtrasTest.cpp
@@ -606,7 +606,7 @@
   EXPECT_EQ(EIR.end(), I);
 }
 
-TEST(STLExtrasTest, splat) {
+TEST(STLExtrasTest, IsSplat) {
   std::vector<int> V;
   EXPECT_FALSE(is_splat(V));
 
@@ -621,6 +621,13 @@
   EXPECT_FALSE(is_splat(V));
 }
 
+TEST(STLExtrasTest, IsSplatInitializerList) {
+  EXPECT_TRUE(is_splat({1}));
+  EXPECT_TRUE(is_splat({1, 1}));
+  EXPECT_FALSE(is_splat({1, 2}));
+  EXPECT_TRUE(is_splat({1, 1, 1}));
+}
+
 TEST(STLExtrasTest, to_address) {
   int *V1 = new int;
   EXPECT_EQ(V1, to_address(V1));