diff --git a/clang/include/clang/Basic/Builtins.def b/clang/include/clang/Basic/Builtins.def
--- a/clang/include/clang/Basic/Builtins.def
+++ b/clang/include/clang/Basic/Builtins.def
@@ -350,6 +350,11 @@
 BUILTIN(__builtin_roundf16, "hh"  , "Fnc")
 BUILTIN(__builtin_roundl, "LdLd"  , "Fnc")
 BUILTIN(__builtin_roundf128, "LLdLLd"  , "Fnc")
+BUILTIN(__builtin_roundeven, "dd"  , "Fnc")
+BUILTIN(__builtin_roundevenf, "ff"  , "Fnc")
+BUILTIN(__builtin_roundevenf16, "hh"  , "Fnc")
+BUILTIN(__builtin_roundevenl, "LdLd"  , "Fnc")
+BUILTIN(__builtin_roundevenf128, "LLdLLd"  , "Fnc")
 BUILTIN(__builtin_scalbln , "ddLi", "Fne")
 BUILTIN(__builtin_scalblnf, "ffLi", "Fne")
 BUILTIN(__builtin_scalblnl, "LdLdLi", "Fne")
@@ -1420,6 +1425,10 @@
 LIBBUILTIN(roundf, "ff", "fnc", MATH_H, ALL_LANGUAGES)
 LIBBUILTIN(roundl, "LdLd", "fnc", MATH_H, ALL_LANGUAGES)
 
+LIBBUILTIN(roundeven, "dd", "fnc", MATH_H, ALL_LANGUAGES)
+LIBBUILTIN(roundevenf, "ff", "fnc", MATH_H, ALL_LANGUAGES)
+LIBBUILTIN(roundevenl, "LdLd", "fnc", MATH_H, ALL_LANGUAGES)
+
 LIBBUILTIN(scalbln, "ddLi", "fne", MATH_H, ALL_LANGUAGES)
 LIBBUILTIN(scalblnf, "ffLi", "fne", MATH_H, ALL_LANGUAGES)
 LIBBUILTIN(scalblnl, "LdLdLi", "fne", MATH_H, ALL_LANGUAGES)
diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -2444,6 +2444,18 @@
                                    Intrinsic::round,
                                    Intrinsic::experimental_constrained_round));
 
+    case Builtin::BIroundeven:
+    case Builtin::BIroundevenf:
+    case Builtin::BIroundevenl:
+    case Builtin::BI__builtin_roundeven:
+    case Builtin::BI__builtin_roundevenf:
+    case Builtin::BI__builtin_roundevenf16:
+    case Builtin::BI__builtin_roundevenl:
+    case Builtin::BI__builtin_roundevenf128:
+      return RValue::get(emitUnaryMaybeConstrainedFPBuiltin(*this, E,
+                                   Intrinsic::roundeven,
+                                   Intrinsic::experimental_constrained_roundeven));
+                                   
     case Builtin::BIsin:
     case Builtin::BIsinf:
     case Builtin::BIsinl:
diff --git a/clang/test/CodeGen/builtins.c b/clang/test/CodeGen/builtins.c
--- a/clang/test/CodeGen/builtins.c
+++ b/clang/test/CodeGen/builtins.c
@@ -411,6 +411,15 @@
   resld = __builtin_roundl(LD);
   // CHECK: call x86_fp80 @llvm.round.f80
 
+  resf = __builtin_roundevenf(F);
+  // CHECK: call float @llvm.roundeven.f32
+
+  resd = __builtin_roundeven(D);
+  // CHECK: call double @llvm.roundeven.f64
+
+  resld = __builtin_roundevenl(LD);
+  // CHECK: call x86_fp80 @llvm.roundeven.f80
+  
   resli = __builtin_lroundf (F);
   // CHECK: call i64 @llvm.lround.i64.f32