Commit 38b09dc3 authored by Nguyen, Thien Minh's avatar Nguyen, Thien Minh
Browse files

Fixed https://github.com/ORNL-QCI/qcor/issues/223 



This is half of the fix: front-end to disconnect the use-def chain before and after the modified gate application.

Todo: extract merging pass also need to respect these gate modifiers
Signed-off-by: default avatarThien Nguyen <nguyentm@ornl.gov>
parent 27525e59

mlir/parsers/qasm3/utils/qasm3_utils.cpp

+29 −0
Original line number Diff line number Diff line
@@ -102,6 +102,35 @@ mlir::Value get_or_extract_qubit(const std::string &qreg_name, 
  }

}



mlir::Value get_or_extract_qubit(const std::string &qubit_name,

                                 mlir::Location location,

                                 ScopedSymbolTable &symbol_table,

                                 mlir::OpBuilder &builder) {

  const std::string qreg_name =

      "__qcor__mlir__single_qubit_register_" + qubit_name;

  if (symbol_table.has_symbol(qubit_name)) {

    mlir::Value qubit_value = symbol_table.get_symbol(qubit_name);

    if (!symbol_table.verify_qubit_ssa_dominance_property(

            qubit_value, builder.getInsertionBlock())) {

      // The cache SSA value is not valid:

      symbol_table.erase_symbol(qubit_name);

      symbol_table.invalidate_qubit_extracts(qreg_name);

      mlir::Value reextracted_qubit =

          get_or_extract_qubit(qreg_name, 0, location, symbol_table, builder);

      symbol_table.add_symbol(qubit_name, reextracted_qubit);

      return reextracted_qubit;

    } else {

      return qubit_value;

    }

  } else {

    symbol_table.invalidate_qubit_extracts(qreg_name);

    mlir::Value reextracted_qubit =

        get_or_extract_qubit(qreg_name, 0, location, symbol_table, builder);

    symbol_table.add_symbol(qubit_name, reextracted_qubit);

    return reextracted_qubit;

  }

}



mlir::Value get_or_create_constant_integer_value(

    const std::size_t idx, mlir::Location location, mlir::Type type,

    ScopedSymbolTable &symbol_table, mlir::OpBuilder &builder) {

mlir/parsers/qasm3/utils/qasm3_utils.hpp

+6 −0
Original line number Diff line number Diff line
@@ -50,6 +50,12 @@ mlir::Value get_or_extract_qubit(const std::string &qreg_name, 
                                 const std::size_t idx, mlir::Location location,

                                 ScopedSymbolTable &symbol_table,

                                 mlir::OpBuilder &builder);

// Get the qubit (possibly re-extract from the internally tracked size-1

// register)

mlir::Value get_or_extract_qubit(const std::string &qubit_name,

                                 mlir::Location location,

                                 ScopedSymbolTable &symbol_table,

                                 mlir::OpBuilder &builder);



mlir::Value get_or_create_constant_integer_value(

    const std::size_t idx, mlir::Location location, mlir::Type int_like_type,

mlir/parsers/qasm3/visitor_handlers/quantum_instruction_handler.cpp

+21 −1
Original line number Diff line number Diff line
@@ -300,6 +300,11 @@ antlrcpp::Any qasm3_visitor::visitQuantumGateCall( 
      auto idx_str = idx_identifier->expressionList()->expression(0)->getText();

      const auto qubit_symbol_name =

          symbol_table.array_qubit_symbol_name(qbit_var_name, idx_str);

      if (!modifiers.empty()) {

        // This is a *modified* instruction, i.e., wrapped gate op

        // must invalidate the qubit SSA use-def chain -> required re-extract:

        symbol_table.erase_symbol(qubit_symbol_name);

      }

      mlir::Value value;

      try {

        // try catch is on this std::stoi(), if idx_str is not an integer,
@@ -361,7 +366,11 @@ antlrcpp::Any qasm3_visitor::visitQuantumGateCall( 


    } else {

      // this is a qubit

      auto qbit = symbol_table.get_symbol(qbit_var_name);

      if (!modifiers.empty()) {

        symbol_table.erase_symbol(qbit_var_name);

      }

      auto qbit =

          get_or_extract_qubit(qbit_var_name, location, symbol_table, builder);

      qbit_values.push_back(qbit);

      qubit_symbol_table_keys.push_back(qbit_var_name);

    }
@@ -402,6 +411,10 @@ antlrcpp::Any qasm3_visitor::visitQuantumGateCall( 
    }

  }



  // Cache these symbol keys before erasing.

  // All qubits involved in modified gate ops (target and controls) need to be

  // re-extracted afterwards.

  const auto cached_qubit_symbol_table_keys = qubit_symbol_table_keys;

  // Potentially get the ctrl qubit

  mlir::Value ctrl_bit;

  if (has_ctrl) {
@@ -512,6 +525,13 @@ antlrcpp::Any qasm3_visitor::visitQuantumGateCall( 
    action_and_extrainfo.pop();

  }



  // Simularly, disconnect the SSA use-def afterward if this is a modified

  // block.

  if (!modifiers.empty()) {

    for (const auto &key : cached_qubit_symbol_table_keys) {

      symbol_table.erase_symbol(key);

    }

  }

  return 0;

}