[Bug tree-optimization/78821] GCC7: Copying whole 32 bits structure field by field not optimised into copying whole 32 bits at once

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78821

--- Comment #21 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Created attachment 42660
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=42660&action=edit
gcc8-pr78821-i386.patch

Untested patch for the -mmovbe movbew loads/stores.  Note, is there any
particular reason why we don't use for AT&T syntax w/l/q suffixes for movbe?
At least looking at binutils testsuite, it covers both movbe without suffix and
movbe[wlq].  On the other side, for bswap insn there are no suffixes.