diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -13940,9 +13940,10 @@
   // float vectors and truncating the result back to half vector. For now, we do
   // this only when HalfArgsAndReturn is set (that is, when the target is arm or
   // arm64).
-  assert(isVector(RHS.get()->getType(), Context.HalfTy) ==
-         isVector(LHS.get()->getType(), Context.HalfTy) &&
-         "both sides are half vectors or neither sides are");
+  assert(
+      (Opc == BO_Comma || isVector(RHS.get()->getType(), Context.HalfTy) ==
+                              isVector(LHS.get()->getType(), Context.HalfTy)) &&
+      "both sides are half vectors or neither sides are");
   ConvertHalfVec =
       needsConversionOfHalfVec(ConvertHalfVec, Context, LHS.get(), RHS.get());
 
diff --git a/clang/test/Sema/fp16vec-sema.c b/clang/test/Sema/fp16vec-sema.c
--- a/clang/test/Sema/fp16vec-sema.c
+++ b/clang/test/Sema/fp16vec-sema.c
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -fsyntax-only -verify %s
+// RUN: %clang_cc1 -fsyntax-only -Wno-unused-value -verify %s
 
 typedef __fp16 half4 __attribute__ ((vector_size (8)));
 typedef float float4 __attribute__ ((vector_size (16)));
@@ -28,6 +28,8 @@
   sv0 = hv0 >= hv1;
   sv0 = hv0 || hv1; // expected-error{{logical expression with vector types 'half4' (vector of 4 '__fp16' values) and 'half4' is only supported in C++}}
   sv0 = hv0 && hv1; // expected-error{{logical expression with vector types 'half4' (vector of 4 '__fp16' values) and 'half4' is only supported in C++}}
+  hv0, 1;
+  1, hv0;
 
   // Implicit conversion between half vectors and float vectors are not allowed.
   hv0 = fv0; // expected-error{{assigning to}}