tfhe_transpiler.h

// Copyright 2021 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

// Helper functions for FHE IR Transpiler.

#ifndef FULLY_HOMOMORPHIC_ENCRYPTION_TRANSPILER_TFHE_TRANSPILER_H_
#define FULLY_HOMOMORPHIC_ENCRYPTION_TRANSPILER_TFHE_TRANSPILER_H_

#include <string>

#include "absl/status/statusor.h"
#include "absl/strings/string_view.h"
#include "transpiler/abstract_xls_transpiler.h"
#include "xls/public/ir.h"

namespace fully_homomorphic_encryption {
namespace transpiler {

// Converts booleanified XLS functions into TFHE-based C++, using the gate ops
// from the TFHE library.
class TfheTranspiler : public AbstractXLSTranspiler<TfheTranspiler> {
 public:
  static absl::StatusOr<std::string> TranslateHeader(
      const xls::Function* function,
      const xlscc_metadata::MetadataOutput& metadata,
      absl::string_view header_path,
      const absl::string_view
          encryption_specific_transpiled_structs_header_path,
      bool skip_scheme_data_deps, const std::vector<std::string>& unwrap);

  static absl::StatusOr<std::string> FunctionSignature(
      const xls::Function* function,
      const xlscc_metadata::MetadataOutput& metadata);

  static std::string CopyNodeToOutput(absl::string_view output_arg, int offset,
                                      const xls::Node* node);
  static std::string CopyParamToNode(const xls::Node* node,
                                     const xls::Node* param, int offset);
  static std::string InitializeNode(const xls::Node* node);

  static absl::StatusOr<std::string> Execute(const xls::Node* node);

  static absl::StatusOr<std::string> Prelude(
      const xls::Function* function,
      const xlscc_metadata::MetadataOutput& metadata);

  static absl::StatusOr<std::string> Conclusion();
};

}  // namespace transpiler
}  // namespace fully_homomorphic_encryption

#endif  // FULLY_HOMOMORPHIC_ENCRYPTION_TRANSPILER_TFHE_TRANSPILER_H_