Index: clang/lib/Headers/avx512bwintrin.h
===================================================================
--- clang/lib/Headers/avx512bwintrin.h
+++ clang/lib/Headers/avx512bwintrin.h
@@ -221,12 +221,18 @@
 
 static __inline__ void __DEFAULT_FN_ATTRS
 _store_mask32(__mmask32 *__A, __mmask32 __B) {
-  *(__mmask32 *)__A = __builtin_ia32_kmovd((__mmask32)__B);
+  struct __store_mask32 {
+    __mmask32 __v;
+  } __attribute__((__packed__, __may_alias__));
+  ((struct __store_mask32 *)__A)->__v = __builtin_ia32_kmovd((__mmask32)__B);
 }
 
 static __inline__ void __DEFAULT_FN_ATTRS
 _store_mask64(__mmask64 *__A, __mmask64 __B) {
-  *(__mmask64 *)__A = __builtin_ia32_kmovq((__mmask64)__B);
+  struct __store_mask64 {
+    __mmask64 __v;
+  } __attribute__((__packed__, __may_alias__));
+  ((struct __store_mask64 *)__A)->__v = __builtin_ia32_kmovq((__mmask64)__B);
 }
 
 /* Integer compare */
Index: clang/lib/Headers/avx512fintrin.h
===================================================================
--- clang/lib/Headers/avx512fintrin.h
+++ clang/lib/Headers/avx512fintrin.h
@@ -8445,7 +8445,10 @@
 
 static __inline__ void __DEFAULT_FN_ATTRS
 _store_mask16(__mmask16 *__A, __mmask16 __B) {
-  *(__mmask16 *)__A = __builtin_ia32_kmovw((__mmask16)__B);
+  struct __store_mask16 {
+    __mmask16 __v;
+  } __attribute__((__packed__, __may_alias__));
+  ((struct __store_mask16 *)__A)->__v = __builtin_ia32_kmovw((__mmask16)__B);
 }
 
 static __inline__ void __DEFAULT_FN_ATTRS512