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diff --git a/infrastructure/m4/ax_check_nonaligned_access.m4 b/infrastructure/m4/ax_check_nonaligned_access.m4
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+++ b/infrastructure/m4/ax_check_nonaligned_access.m4
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+dnl @synopsis AX_CHECK_NONALIGNED_ACCESS
+dnl
+dnl This macro will see if non-aligned memory accesses will fail. The following
+dnl defines will be made as appropriate:
+dnl HAVE_ALIGNED_ONLY_INT16
+dnl HAVE_ALIGNED_ONLY_INT32
+dnl HAVE_ALIGNED_ONLY_INT64
+dnl
+dnl @category C
+dnl @author Martin Ebourne
+dnl @version 2005/07/12
+dnl @license AllPermissive
+
+AC_DEFUN([AX_CHECK_NONALIGNED_ACCESS], [
+  AC_CACHE_CHECK([if non-aligned 16 bit word accesses fail], [have_aligned_only_int16],
+    [AC_RUN_IFELSE([AC_LANG_PROGRAM([[$ac_includes_default]], [[
+        #ifndef HAVE_UINT16_T
+          #define uint16_t u_int16_t;
+        #endif
+        uint16_t scratch[2];
+        memset(scratch, 0, sizeof(scratch));
+        return *(uint16_t*)((char*)scratch+1);
+      ]])],
+      [have_aligned_only_int16=no], [have_aligned_only_int16=yes]
+    )])
+  if test "x$have_aligned_only_int16" = "xyes"; then
+    AC_DEFINE([HAVE_ALIGNED_ONLY_INT16], 1, [Define to 1 if non-aligned int16 access will fail])
+  fi
+  AC_CACHE_CHECK([if non-aligned 32 bit word accesses fail], [have_aligned_only_int32],
+    [AC_RUN_IFELSE([AC_LANG_PROGRAM([[$ac_includes_default]], [[
+        #ifndef HAVE_UINT32_T
+          #define uint32_t u_int32_t;
+        #endif
+        uint32_t scratch[2];
+        memset(scratch, 0, sizeof(scratch));
+        return *(uint32_t*)((char*)scratch+1);
+      ]])],
+      [have_aligned_only_int32=no], [have_aligned_only_int32=yes]
+    )])
+  if test "x$have_aligned_only_int32" = "xyes"; then
+    AC_DEFINE([HAVE_ALIGNED_ONLY_INT32], 1, [Define to 1 if non-aligned int32 access will fail])
+  fi
+  AC_CACHE_CHECK([if non-aligned 64 bit word accesses fail], [have_aligned_only_int64],
+    [AC_RUN_IFELSE([AC_LANG_PROGRAM([[$ac_includes_default]], [[
+        #ifndef HAVE_UINT64_T
+          #define uint64_t u_int64_t;
+        #endif
+        uint64_t scratch[2];
+        memset(scratch, 0, sizeof(scratch));
+        return *(uint64_t*)((char*)scratch+1);
+      ]])],
+      [have_aligned_only_int64=no], [have_aligned_only_int64=yes]
+    )])
+  if test "x$have_aligned_only_int64" = "xyes"; then
+    AC_DEFINE([HAVE_ALIGNED_ONLY_INT64], 1, [Define to 1 if non-aligned int64 access will fail])
+  fi
+  ])dnl