5.14.3.4 The #pragma Intrinsic Directive

The #pragma intrinsic directive is used to indicate to the compiler that a function will be inlined intrinsically by the compiler. This directive should never be used with user-defined code.

You should not attempt to redefine an existing library function that uses the intrinsic pragma. If you need to develop your own version of such a routine, it must not use the same name as the intrinsic function. For example, if you need to develop your own version of memcpy(), give this a unique name, such as sp_memcpy(). Check the standard header files to determine which library functions use this pragma.