Actually not, on "recent"/"not too old" x86_64 architecture, "rep movsX" instructions are now hardware accelerated for short and big memory blocks. Memcpy and o

Actually not, on "recent"/"not too old" x86_64 architecture, "rep movsX" instructions are now hardware accelerated for short and big memory blocks. Memcpy and other basic memory operations are getting their code generated directly by the compiler which shortcuts the OS runtime.