[Bug ipa/77472] build of intel_drv.so (xf86-video-intel) takes over 13GB+ memory during lto1

[trippels at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77472

Markus Trippelsdorf <trippels at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |compile-time-hog, lto,
                   |                            |memory-hog
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2016-09-04
                 CC|                            |trippels at gcc dot gnu.org
          Component|lto                         |ipa
     Ever confirmed|0                           |1

--- Comment #1 from Markus Trippelsdorf <trippels at gcc dot gnu.org> ---
Confirmed.

gcc spends ages in ipa inline analysis at WPA time (~4GB used):

Overhead  Shared Object  Symbol
  41.71%  lto1           [.] estimate_calls_size_and_time
  22.29%  lto1           [.] update_callee_keys

then at LTRANS time:

Overhead  Shared Object                  Symbol                                 
  72.35%  lto1                           [.] get_abnormal_succ_dispatcher       
   2.11%  lto1                           [.] htab_find_slot_with_hash  

more and more memory gets used.

(Clang -flto manages with under 400KB)

Will try to come up with a testcase tomorrow.