[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

[rguenth at gcc dot gnu.org]

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

--- Comment #18 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #17)
> Created attachment 34975 [details]
> do not compute live/conflict for abnormal coalesces
> 
> This is the other idea of simply not computing live/conflict for abnormal
> coalesces we know to always succeed.  This shrinks the following
> live/conflict
> problem for the regular coalesces by unifying some partitions.
> 
> Doesn't help this particular testcase much.

But it fixes PR63155 ...