diff --git a/include/assume_aligned.h b/include/assume_aligned.h
new file mode 100644
index 00000000000..89f88c1b728
--- /dev/null
+++ b/include/assume_aligned.h
@@ -0,0 +1,70 @@
+/*
+   Copyright (c) 2000, 2012, Oracle and/or its affiliates.
+   Copyright (c) 2020, MariaDB Corporation.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335  USA */
+
+#pragma once
+
+#include <cassert>
+#include <cstring>
+
+#ifdef _MSC_VER
+template <std::size_t Alignment, class T>
+static inline T my_assume_aligned(T ptr)
+{
+  assert(reinterpret_cast<size_t>(ptr) % Alignment == 0);
+  __assume(reinterpret_cast<size_t>(ptr) % Alignment == 0);
+  return ptr;
+}
+#else
+template <std::size_t Alignment, class T>
+static inline T my_assume_aligned(T ptr)
+{
+  assert(reinterpret_cast<size_t>(ptr) % Alignment == 0);
+  return static_cast<T>(__builtin_assume_aligned(ptr, Alignment));
+}
+#endif
+
+template <std::size_t Alignment>
+inline void *memcpy_aligned(void *dest, const void *src, size_t n)
+{
+  static_assert(Alignment && !(Alignment & (Alignment - 1)), "power of 2");
+
+  return std::memcpy(my_assume_aligned<Alignment>(dest),
+                     my_assume_aligned<Alignment>(src), n);
+}
+template <std::size_t Alignment>
+inline void *memmove_aligned(void *dest, const void *src, size_t n)
+{
+  static_assert(Alignment && !(Alignment & (Alignment - 1)), "power of 2");
+
+  return std::memmove(my_assume_aligned<Alignment>(dest),
+                      my_assume_aligned<Alignment>(src), n);
+}
+template <std::size_t Alignment>
+inline int memcmp_aligned(const void *s1, const void *s2, size_t n)
+{
+  static_assert(Alignment && !(Alignment & (Alignment - 1)), "power of 2");
+
+  return std::memcmp(my_assume_aligned<Alignment>(s1),
+                     my_assume_aligned<Alignment>(s2), n);
+}
+template <std::size_t Alignment>
+inline void *memset_aligned(void *s, int c, size_t n)
+{
+  static_assert(Alignment && !(Alignment & (Alignment - 1)), "power of 2");
+
+  return std::memset(my_assume_aligned<Alignment>(s), c, n);
+}
diff --git a/include/m_string.h b/include/m_string.h
index 9e786908dc6..e4c11d24c0b 100644
--- a/include/m_string.h
+++ b/include/m_string.h
@@ -195,53 +195,6 @@ extern ulonglong strtoull(const char *str, char **ptr, int base);
 
 #if defined(__cplusplus)
 }
-
-# ifdef _MSC_VER
-template <size_t Alignment, class T> static inline T my_assume_aligned(T ptr)
-{
-  DBUG_ASSERT(reinterpret_cast<size_t>(ptr) % Alignment == 0);
-  __assume(reinterpret_cast<size_t>(ptr) % Alignment == 0);
-  return ptr;
-}
-# else
-template <size_t Alignment, class T> static inline T my_assume_aligned(T ptr)
-{
-  DBUG_ASSERT(reinterpret_cast<size_t>(ptr) % Alignment == 0);
-  return static_cast<T>(__builtin_assume_aligned(ptr, Alignment));
-}
-# endif
-
-template <size_t Alignment>
-inline void *memcpy_aligned(void *dest, const void *src, size_t n)
-{
-  static_assert(Alignment && !(Alignment & (Alignment - 1)), "power of 2");
-
-  return memcpy(my_assume_aligned<Alignment>(dest),
-                my_assume_aligned<Alignment>(src), n);
-}
-template <size_t Alignment>
-inline void *memmove_aligned(void *dest, const void *src, size_t n)
-{
-  static_assert(Alignment && !(Alignment & (Alignment - 1)), "power of 2");
-
-  return memmove(my_assume_aligned<Alignment>(dest),
-                 my_assume_aligned<Alignment>(src), n);
-}
-template <size_t Alignment>
-inline int memcmp_aligned(const void *s1, const void *s2, size_t n)
-{
-  static_assert(Alignment && !(Alignment & (Alignment - 1)), "power of 2");
-
-  return memcmp(my_assume_aligned<Alignment>(s1),
-                my_assume_aligned<Alignment>(s2), n);
-}
-template <size_t Alignment>
-inline void *memset_aligned(void *s, int c, size_t n)
-{
-  static_assert(Alignment && !(Alignment & (Alignment - 1)), "power of 2");
-
-  return memset(my_assume_aligned<Alignment>(s), c, n);
-}
 #endif
 
 #include <mysql/plugin.h>
diff --git a/storage/innobase/buf/buf0buf.cc b/storage/innobase/buf/buf0buf.cc
index 1e181872e87..7df8815d73f 100644
--- a/storage/innobase/buf/buf0buf.cc
+++ b/storage/innobase/buf/buf0buf.cc
@@ -31,6 +31,7 @@ The database buffer buf_pool
 Created 11/5/1995 Heikki Tuuri
 *******************************************************/
 
+#include "assume_aligned.h"
 #include "mtr0types.h"
 #include "mach0data.h"
 #include "buf0buf.h"
diff --git a/storage/innobase/include/buf0flu.ic b/storage/innobase/include/buf0flu.ic
index 6f57bcb6fc8..4a3ecb57938 100644
--- a/storage/innobase/include/buf0flu.ic
+++ b/storage/innobase/include/buf0flu.ic
@@ -24,6 +24,7 @@ The database buffer pool flush algorithm
 Created 11/5/1995 Heikki Tuuri
 *******************************************************/
 
+#include "assume_aligned.h"
 #include "buf0buf.h"
 #include "mtr0mtr.h"
 #include "srv0srv.h"
diff --git a/storage/innobase/include/fsp0fsp.h b/storage/innobase/include/fsp0fsp.h
index eef8f94020f..983b7e11c95 100644
--- a/storage/innobase/include/fsp0fsp.h
+++ b/storage/innobase/include/fsp0fsp.h
@@ -27,6 +27,7 @@ Created 12/18/1995 Heikki Tuuri
 #ifndef fsp0fsp_h
 #define fsp0fsp_h
 
+#include "assume_aligned.h"
 #include "fsp0types.h"
 #include "fut0lst.h"
 #include "ut0byte.h"
diff --git a/storage/innobase/log/log0crypt.cc b/storage/innobase/log/log0crypt.cc
index 3bdc375b229..e22ef10f44b 100644
--- a/storage/innobase/log/log0crypt.cc
+++ b/storage/innobase/log/log0crypt.cc
@@ -27,6 +27,7 @@ MDEV-11782: Rewritten for MariaDB 10.2 by Marko Mäkelä, MariaDB Corporation.
 #include <my_global.h>
 #include "log0crypt.h"
 #include <mysql/service_my_crypt.h>
+#include "assume_aligned.h"
 
 #include "log0crypt.h"
 #include "log0recv.h"  // for recv_sys