message: [XLA] Remove unused parameters when simplifying graph in memory space assignment
diff: @@ -37,7 +37,6 @@ float MemorySpaceAssignmentCostAnalysis::GetInstructionElapsedDueToMemory(
  absl::optional<int64> operand_in_alternate_mem,
  bool output_in_alternate_mem) const {
  float bytes_accessed = cost_analysis_.bytes_accessed(instruction);
  - VLOG(4) << " bytes_accessed = " << bytes_accessed;
  float elapsed_due_to_bytes =
  bytes_accessed /
  cost_analysis_.per_second_rate(HloCostAnalysis::kBytesAccessedKey);
  @@ -124,8 +123,6 @@ void CostAnalysisPrefetchIntervalPicker::SetInstructionSchedule(
  instructions_elapsed_time.resize(logical_time + 1, 0.0);
  }
  instructions_elapsed_time[logical_time] = elapsed_time;
  - VLOG(4) << "Elapsed time in seconds [" << logical_time
  - << "] = " << elapsed_time;
  }
  // As an optimization, create a cumulative sum vector of elapsed time.
  float cumsum = 0.0;
  @@ -1083,6 +1080,9 @@ void PresetAssignments::RemoveAssignmentForInstruction(
  Status MemorySpaceAssignment::SimplifyGraph() {
  for (HloComputation* computation : module_->MakeNonfusionComputations()) {
  + // FixSchedule can miss unused parameters. Just remove unused parameters
  + // here so that FixSchedule doesn't have to deal with them.
  + TF_RETURN_IF_ERROR(computation->RemoveUnusedParametersFromAnyComputation());
  // We perform limited DCE and forward the tuple operand in patterns like
  // GetTupleElement(Tuple(a, b), 0). This is mostly because memory space
  // assignment is ran late in compilation (after DCE and arithmetic
  