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
Index: clang/test/CodeGen/X86/avx512bw-builtins.c
===================================================================
--- clang/test/CodeGen/X86/avx512bw-builtins.c
+++ clang/test/CodeGen/X86/avx512bw-builtins.c
@@ -364,13 +364,13 @@
 
 void test_store_mask32(__mmask32 *A, __m512i B, __m512i C) {
   // CHECK-LABEL: @test_store_mask32
-  // CHECK: store i32 %{{.*}}, ptr %{{.*}}
+  // CHECK: store i32 %{{.*}}, ptr %{{.*}}, align 1
   _store_mask32(A, _mm512_cmpneq_epu16_mask(B, C));
 }
 
 void test_store_mask64(__mmask64 *A, __m512i B, __m512i C) {
   // CHECK-LABEL: @test_store_mask64
-  // CHECK: store i64 %{{.*}}, ptr %{{.*}}
+  // CHECK: store i64 %{{.*}}, ptr %{{.*}}, align 1
   _store_mask64(A, _mm512_cmpneq_epu8_mask(B, C));
 }
 
Index: clang/test/CodeGen/X86/avx512f-builtins.c
===================================================================
--- clang/test/CodeGen/X86/avx512f-builtins.c
+++ clang/test/CodeGen/X86/avx512f-builtins.c
@@ -8527,7 +8527,7 @@
 void test_store_mask16(__mmask16 *A, __m512i B, __m512i C) {
   // CHECK-LABEL: @test_store_mask16
   // CHECK: bitcast <16 x i1> %{{.*}} to i16
-  // CHECK: store i16 %{{.*}}, ptr %{{.*}}
+  // CHECK: store i16 %{{.*}}, ptr %{{.*}}, align 1
   _store_mask16(A, _mm512_cmpneq_epu32_mask(B, C));
 }