tree ae750541f8da2aad99c696cea62c2d2235f8511f
parent 00b33b6523346fc06fac96a94e61bf50ccfdcde8
author Sameer Agarwal <sameeragarwal@google.com> 1726441186 -0700
committer Sameer Agarwal <sameeragarwal@google.com> 1726523514 +0000

Use absl hash containers for graph algorithms

This reduces pre-processor time when finding an
ordering automatically substantially.

Before:

ComputeStableSchurOrdering
                                        Delta   Cumulative
              CreateHessianGraph :    0.50324      0.50324
                     Preordering :    0.00692      0.51017
            StableIndependentSet :    0.26341      0.77358
         ConstantParameterBlocks :    0.00095      0.77453
                           Total :    0.23978      1.01431

After:

ComputeStableSchurOrdering
                                        Delta   Cumulative
              CreateHessianGraph :    0.17183      0.17183
                     Preordering :    0.00226      0.17409
            StableIndependentSet :    0.12510      0.29919
         ConstantParameterBlocks :    0.00073      0.29991
                           Total :    0.01638      0.31629

Change-Id: I50bbac69f8b3f19240a61a218913cebf34da0db5