[Bug middle-end/64928] [4.8/4.9/5 Regression] Inordinate cpu time and memory usage in "phase opt and generate" with -ftest-coverage -fprofile-arcs

[law at redhat dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64928

--- Comment #13 from Jeffrey A. Law <law at redhat dot com> ---
I think we've done similar things for Brad's large testcases in the past.  You
want to look at both the edge/bb density as well as the overall size.  ie, a
high density doesn't really hurt if the total cfg is small.

See "is_too_expensive" in gcse.c for the current heuristics to avoid trying
global opts on these kinds of testcases.