[Bug middle-end/71874] [4.9 Regression] memmove works wrong

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71874

--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Created attachment 38928
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=38928&action=edit
gcc49-pr71874-1.patch

One possible untested patch.