Commit c1fa33e6 authored by Nguyen, Thien Minh's avatar Nguyen, Thien Minh
Browse files

Added gate merging to the list of passes 



Tested by: printing out runtime optimization data.

Signed-off-by: default avatarThien Nguyen <nguyentm@ornl.gov>
parent af67d2ed

runtime/qrt/pass_manager.cpp

+19 −9
Original line number Diff line number Diff line
@@ -45,21 +45,31 @@ PassManager::PassManager(int level) : m_level(level) {} 


std::vector<PassStat> PassManager::optimize(

    std::shared_ptr<xacc::CompositeInstruction> program) const {



  // We only support level 1 atm.

  if (m_level != 1) {

    return {};

  std::vector<PassStat> passData;

  // Selects the list of passes based on the optimization level.

  const auto passesToRun = [&]() {

    if (m_level == 1) {

      return std::vector<std::string>(std::begin(LEVEL1_PASSES),

                                      std::end(LEVEL1_PASSES));

    } else if (m_level == 2) {

      return std::vector<std::string>(std::begin(LEVEL2_PASSES),

                                      std::end(LEVEL2_PASSES));

    }

    return std::vector<std::string>();

  }();



  std::vector<PassStat> passData;

  for (const auto &passName : LEVEL1_PASSES) {

  for (const auto &passName : passesToRun) {

    PassStat stat;

    stat.passName = passName;

    // Counts gate before:

    stat.gateCountBefore = PassStat::countGates(program);

    xacc::ScopeTimer timer(passName, false);

    auto xaccOptTransform = xacc::getService<xacc::IRTransformation>(passName);

    auto xaccOptTransform =

        xacc::getService<xacc::IRTransformation>(passName, false);

    // Graciously ignores passes which cannot be located.

    if (xaccOptTransform) {

      xaccOptTransform->apply(program, nullptr);

    }

    // Stores the elapsed time.

    stat.wallTimeMs = timer.getDurationMs();

    // Counts gate after:

runtime/qrt/pass_manager.hpp

+22 −4
Original line number Diff line number Diff line
@@ -34,10 +34,28 @@ public: 
  // List of passes for level 1:

  // Ordered list of passes to be executed.

  // Can have duplicated entries (run multiple times).

  static const constexpr char *const LEVEL1_PASSES[] = {"rotation-folding",

                                                        "circuit-optimizer"};

  // TODO: define other levels if neccesary:

  // e.g. could be looping those passes multiple times.

  static const constexpr char *const LEVEL1_PASSES[] = {

    "rotation-folding",

    // Merge single-qubit gates before running the circuit-optimizer

    // so that there are potentially more patterns emerged.

    "single-qubit-gate-merging",

    "circuit-optimizer",

  };



  // Level 2 is experimental, brute-force optimization

  // which could result in long runtime.

  static const constexpr char *const LEVEL2_PASSES[] = {

    "rotation-folding",

    "single-qubit-gate-merging",

    "circuit-optimizer",

    // Try to look for any two-qubit blocks

    // which can be simplified.

    "two-qubit-block-merging",

    // Re-run those simpler optimizers to 

    // make sure all simplification paterns are captured.

    "single-qubit-gate-merging",

    "circuit-optimizer",

  };

private:

  int m_level;

};