[Bug ipa/92535] [10/11 regression] ICF is relatively expensive and became less effective

[hubicka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92535

Jan Hubicka <hubicka at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|unassigned at gcc dot gnu.org      |hubicka at gcc dot gnu.org

--- Comment #7 from Jan Hubicka <hubicka at gcc dot gnu.org> ---
With today trunk (after icf memory handling patches) I get 
     VM SIZE                          FILE SIZE
 ++++++++++++++ GROWING            ++++++++++++++
  +1.3% +1.21Mi .text              +1.21Mi  +1.3%
  +5.2%  +440Ki .eh_frame           +440Ki  +5.2%
  +7.1%  +126Ki .eh_frame_hdr       +126Ki  +7.1%
  +0.4% +74.8Ki .rodata            +74.8Ki  +0.4%
  +0.6% +61.0Ki .rela.dyn          +61.0Ki  +0.6%
  +0.4% +15.4Ki .data.rel.ro.local +15.4Ki  +0.4%
  +1.1% +11.1Ki .data.rel.ro       +11.1Ki  +1.1%
  [ = ]       0 .symtab            +2.55Ki  +0.0%
  +0.0%     +64 .data                  +64  +0.0%
  +0.0%     +24 .rela.plt              +24  +0.0%
  +0.0%     +16 .plt                   +16  +0.0%
  +0.2%     +12 .gcc_except_table      +12  +0.2%
  +0.0%      +8 .got.plt                +8  +0.0%

 -------------- SHRINKING          --------------
  [ = ]       0 .strtab            -29.6Ki  -0.1%
  -0.0%     -32 .bss                     0  [ = ]
  -0.0%      -8 .got                    -8  -0.0%

 -+-+-+-+-+-+-+ MIXED              +-+-+-+-+-+-+-
   +17%     +44 [Unmapped]         -3.74Ki -90.8%

  +1.3% +1.92Mi TOTAL              +1.89Mi  +0.9%

time report of WPA with ICF:
 ipa lto gimple in                  :   6.45 (  4%)   2.65 ( 16%)   9.04 (  5%)
  810M ( 12%)
 ipa lto gimple out                 :   1.87 (  1%)   0.80 (  5%)   2.72 (  1%)
    0  (  0%)
 ipa lto decl in                    :  18.63 ( 11%)   1.26 (  7%)  20.02 ( 10%)
 2682M ( 41%)
 ipa lto decl out                   :   4.64 (  3%)   0.20 (  1%)   4.84 (  3%)
    0  (  0%)
 ipa icf                            :  17.58 ( 10%)   0.59 (  4%)  18.22 (  9%)
   24M (  0%)
 TOTAL                              : 176.22         16.82        193.31       
 6617M

compared to:
 ipa lto gimple in                  :   0.48 (  0%)   0.11 (  1%)   0.77 (  1%)
 2905k (  0%)
 ipa lto gimple out                 :   1.01 (  1%)   0.84 (  8%)   1.84 (  1%)
    0  (  0%)
 ipa lto decl in                    :  18.74 ( 14%)   1.31 ( 12%)  19.90 ( 13%)
 2682M ( 47%)
 ipa lto decl out                   :   4.34 (  3%)   0.47 (  4%)   4.79 (  3%)
    0  (  0%)
 TOTAL                              : 138.62         10.61        149.39       
 5715M

So still pretty bad.