[Bug tree-optimization/84737] [8 Regression] 20% degradation in CPU2000 172.mgrid starting with r256888

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84737

Martin Liška <marxin at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|WAITING                     |NEW
                 CC|                            |jamborm at gcc dot gnu.org

--- Comment #6 from Martin Liška <marxin at gcc dot gnu.org> ---
I see, the change is only in resid_.constprop.1 that is created after the
patch:

before:

Evaluating opportunities for resid/1.
 - considering value &x.u for param #0 u (caller_count: 3)
     good_cloning_opportunity_p (time: 1, size: 169, freq_sum: 38778) ->
evaluation: 229, threshold: 500
     good_cloning_opportunity_p (time: 1, size: 169, freq_sum: 38778) ->
evaluation: 229, threshold: 500
 - considering value &x.v for param #1 v (caller_count: 3)
     good_cloning_opportunity_p (time: 1, size: 169, freq_sum: 38778) ->
evaluation: 229, threshold: 500
     good_cloning_opportunity_p (time: 1, size: 169, freq_sum: 38778) ->
evaluation: 229, threshold: 500
 - considering value &x.r for param #2 r (caller_count: 3)
     good_cloning_opportunity_p (time: 1, size: 169, freq_sum: 38778) ->
evaluation: 229, threshold: 500
     good_cloning_opportunity_p (time: 2, size: 246, freq_sum: 38778) ->
evaluation: 315, threshold: 500
 - considering value &x.a for param #4 a (caller_count: 4)
     good_cloning_opportunity_p (time: 1, size: 169, freq_sum: 42518) ->
evaluation: 251, threshold: 500
     good_cloning_opportunity_p (time: 1, size: 169, freq_sum: 42518) ->
evaluation: 251, threshold: 500

after:

Evaluating opportunities for resid/1.
 - considering value &x.u for param #0 u (caller_count: 3)
     good_cloning_opportunity_p (time: 1, size: 169, freq_sum: 74554) ->
evaluation: 441, threshold: 500
     good_cloning_opportunity_p (time: 1, size: 169, freq_sum: 74554) ->
evaluation: 441, threshold: 500
 - considering value &x.v for param #1 v (caller_count: 3)
     good_cloning_opportunity_p (time: 1, size: 169, freq_sum: 74554) ->
evaluation: 441, threshold: 500
     good_cloning_opportunity_p (time: 1, size: 169, freq_sum: 74554) ->
evaluation: 441, threshold: 500
 - considering value &x.r for param #2 r (caller_count: 3)
     good_cloning_opportunity_p (time: 1, size: 169, freq_sum: 74554) ->
evaluation: 441, threshold: 500
     good_cloning_opportunity_p (time: 2, size: 246, freq_sum: 74554) ->
evaluation: 606, threshold: 500
  Creating a specialized node of resid/1.

Martin can you please take a look and evaluate how profitable is that
transformation? Maybe it can help you
with tuning of the param as in PR84149.

Thanks