[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 #6 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Created attachment 38929
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=38929&action=edit
gcc49-pr71874-2.patch

Another patch, using get_addr_base_and_unit_offset.  This one optimizes
__builtin_memmove (str + 20, str + 15, 4);
into memcpy while the other patch doesn't.