[Bug rtl-optimization/117922] [15 Regression] 1000% compilation time slow down on the testcase from pr26854

[rsandifo at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117922

--- Comment #23 from Richard Sandiford <rsandifo at gcc dot gnu.org> ---
FWIW, running locally on x86 with fold_mem_offsets disabled (admittedly with
rtl checking), I see:

 combiner                           :   0.91 (  0%)    21M (  0%)
 late combiner                      :   1.31 (  0%)  1329k (  0%)

and:

 forward prop                       :   1.41 (  0%)  1028k (  0%)

This includes two late-combine runs (one before and one after RA) and two
fwprop runs.

So the time and memory overhead seem reasonable for this particular testcase. 
That obviously doesn't mean that it's free of scaling problems elsewhere, of
course.