[Bug rtl-optimization/68173] gcc takes a long time and a lot of memory with -O0 on source file with very large expression

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68173

--- Comment #10 from Richard Biener <rguenth at gcc dot gnu.org> ---
Created attachment 36779
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=36779&action=edit
cut-down testcase

Cut-down testcase.  With GCC 5 needs 7.5s (-O0) vs. 2.1s (-O1)