[Bug tree-optimization/54146] Very slow compile with attribute((flatten))

[steven at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54146

--- Comment #30 from Steven Bosscher <steven at gcc dot gnu.org> 2012-08-07 22:36:30 UTC ---
> Created attachment 27957 [details]

With the attachment, time spent in rewrite_into_loop_closed_ssa is almost 0
(and that includes the time in the verifier). Compile time for the test case
(still with only "check<CGAL::Gmpfi>();") is now 924s wall time. Top spenders:

integrated RA                   : 224.26 (24%)
tree SSA incremental            :  75.07 ( 8%)
df live&initialized regs        :  69.58 ( 8%)
df live regs                    :  66.19 ( 7%)
remove unused locals            :  53.43 ( 6%)
out of ssa                      :  51.93 ( 6%)