[Bug middle-end/52835] [4.7/4.8 Regression] -O3 wrongly optimizes loop __builtin_memcpy away

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52835

--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-04-02 19:38:31 UTC ---
Created attachment 27069
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=27069
gcc48-pr52835.patch

Untested fix.  Ignoring failures from compute_*loop can't be right.