Further speedup to CSR back-substitution using dof_simplenum.

PiperOrigin-RevId: 711440268
Change-Id: I81cd9a6a8b8ec78d08cfbc34f60a9216ea753833

test/benchmark/CMakeLists.txt

@@ -44,7 +44,7 @@ mujoco_test(
 )
 
 mujoco_test(
-  engine_core_smooth_benchmark_test
+  solveLD_benchmark_test
   MAIN_TARGET benchmark::benchmark_main
   ADDITIONAL_LINK_LIBRARIES benchmark::benchmark absl::core_headers
 )

test/benchmark/solveLD_benchmark_test.cc

@@ -64,7 +64,8 @@ static void BM_solveLD(benchmark::State& state, bool featherstone, bool coil) {
       } else {
         mju_copy(res, vec, m->nv);
         mj_solveLDs(res, LDs, d->qLDiagInv, m->nv,
-                    d->C_rownnz, d->C_rowadr, d->C_diag, d->C_colind);
+                    d->C_rownnz, d->C_rowadr, d->C_diag, m->dof_simplenum,
+                    d->C_colind);
       }
     }
   }