Method RunPasses

source/reduce/reducer.cpp:160–246

}

Reducer::ReductionResultStatus Reducer::RunPasses(
    std::vector<std::unique_ptr<ReductionPass>>* passes,
    spv_const_reducer_options options, spv_validator_options validator_options,
    const SpirvTools& tools, std::vector<uint32_t>* current_binary,
    uint32_t* const reductions_applied) {
  // Determines whether, on completing one round of reduction passes, it is
  // worthwhile trying a further round.
  bool another_round_worthwhile = true;

  // Apply round after round of reduction passes until we hit the reduction
  // step limit, or deem that another round is not going to be worthwhile.
  while (!ReachedStepLimit(*reductions_applied, options) &&
         another_round_worthwhile) {
    // At the start of a round of reduction passes, assume another round will
    // not be worthwhile unless we find evidence to the contrary.
    another_round_worthwhile = false;

    // Iterate through the available passes.
    for (auto& pass : *passes) {
      // If this pass hasn't reached its minimum granularity then it's
      // worth eventually doing another round of reductions, in order to
      // try this pass at a finer granularity.
      another_round_worthwhile |= !pass->ReachedMinimumGranularity();

      // Keep applying this pass at its current granularity until it stops
      // working or we hit the reduction step limit.
      consumer_(SPV_MSG_INFO, nullptr, {},
                ("Trying pass " + pass->GetName() + ".").c_str());
      do {
        auto maybe_result =
            pass->TryApplyReduction(*current_binary, options->target_function);
        if (maybe_result.empty()) {
          // For this round, the pass has no more opportunities (chunks) to
          // apply, so move on to the next pass.
          consumer_(
              SPV_MSG_INFO, nullptr, {},
              ("Pass " + pass->GetName() + " did not make a reduction step.")
                  .c_str());
          break;
        }
        bool interesting = false;
        std::stringstream stringstream;
        (*reductions_applied)++;
        stringstream << "Pass " << pass->GetName() << " made reduction step "
                     << *reductions_applied << ".";
        consumer_(SPV_MSG_INFO, nullptr, {}, (stringstream.str().c_str()));
        if (!tools.Validate(&maybe_result[0], maybe_result.size(),
                            validator_options)) {
          // The reduction step went wrong and an invalid binary was produced.
          // By design, this shouldn't happen; this is a safeguard to stop an
          // invalid binary from being regarded as interesting.
          consumer_(SPV_MSG_INFO, nullptr, {},
                    "Reduction step produced an invalid binary.");
          if (options->fail_on_validation_error) {
            // In this mode, we fail, so we update the current binary so it is
            // output for debugging.
            *current_binary = std::move(maybe_result);
            return Reducer::ReductionResultStatus::kStateInvalid;