[Bug middle-end/64928] [7/8/9 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 #27 from Richard Biener <rguenth at gcc dot gnu.org> ---
Btw, on trunk for the small testcase the main peak memory user is

Bitmaps                                                 Leak            Peak   
        Times  N searches Search iter      Type
--------------------------------------------------------------------------------------------------------------------------------------------
...
tree-ssa-live.c:931 (new_tree_live_info)         4089900520: 42.6%4089900600
102257849: 11.3%       35539       42909      heap
tree-ssa-live.c:932 (new_tree_live_info)         4099840160: 42.7%4099840200
103153730: 11.4%      326917       98706      heap
--------------------------------------------------------------------------------------------------------------------------------------------
Total                                            9592285400                 
906070505

that's livein/liveout.  SSA conflicts are probably similar but harder
to decipher from the stats:

tree-ssa-coalesce.c:586 (ssa_conflicts_add_one)       43056:  0.0%    198672   
398160:  0.0%       19205       39415      heap

next top is

df-problems.c:4400 (df_md_alloc)                  218129480:  2.3% 218146320  
5654706:  0.6%       71264      127594      heap
df-problems.c:4401 (df_md_alloc)                  218142960:  2.3% 218159920  
5640467:  0.6%       71675      127395      heap