[Bug rtl-optimization/116645] [13/14/15 regression] Huge performance loss after 13.2.0 compiler upgrade; reload CSE regs has scalability issues

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116645

--- Comment #7 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #6)
> I'm checking if it was fixed by r15-2218-g44e065a52fa606

Nope.  The profile is still

Samples: 93K of event 'cycles:Pu', Event count (approx.): 122100166487          
Overhead       Samples  Command  Shared Object         Symbol                   
  37.71%         35113  cc1plus  cc1plus               [.]
_ZN10hash_tableI13cselib_hasherLb0E11xcallocatorE19find_slot_with_hashERKPNS0_3keyEj13insert_option
  12.84%         11958  cc1plus  cc1plus               [.]
_Z22rtx_equal_for_cselib_1P7rtx_defS0_12machine_modei
   5.75%          5359  cc1plus  cc1plus               [.]
_ZL13autoinc_splitP7rtx_defPS0_12machine_mode

what looks still dubious is the uses of new_cselib_val with 'next_uid' as
hash and how they are put into the hashtable (how we ever going to find those
again).