Added u1 precision for binary weights (#3914)

* Added U1 precision for binary weights

* Handle switch cases with u1 type

* Fixed code style

* Added convert_to_string support for u1 type

* Use real C type  for u1 type.
Co-Authored-By: Robert Kimball <robert.kimball@intel.com>

src/contrib/mlir/core/pass/ng_dialect_builder.cpp

@@ -238,6 +238,7 @@ mlir::Type NgDialectConversionPass::getMlirType(const element::Type& type)
     {
     case ngraph::element::Type_t::undefined:
     case ngraph::element::Type_t::dynamic:
+    case ngraph::element::Type_t::u1:
     default: NGRAPH_CHECK(false, "MLIR: Unsupported NGraph types"); break;
     case ngraph::element::Type_t::bf16: return mlir::NGFloatType::getBF16(m_context);
     case ngraph::element::Type_t::f16: return mlir::NGFloatType::getF16(m_context);

src/ngraph/builder/make_constant.hpp

@@ -94,6 +94,8 @@ namespace ngraph
                 throw ngraph_error("make_constant: Unsupported element type 'dynamic'");
             case element::Type_t::boolean:
                 throw ngraph_error("make_constant: Unsupported element type 'boolean'");
+            case element::Type_t::u1:
+                throw ngraph_error("make_constant: Unsupported element type 'u1'");
             case element::Type_t::undefined:
                 throw ngraph_error("make_constant: Unsupported element type 'undefined'");
             }

src/ngraph/distributed/open_mpi.hpp

@@ -196,6 +196,7 @@ namespace ngraph
                 case element::Type_t::u64: m_type = MPI_UNSIGNED_LONG; break;
                 case element::Type_t::bf16:
                 case element::Type_t::f16:
+                case element::Type_t::u1:
                 case element::Type_t::undefined:
                 case element::Type_t::dynamic: throw std::runtime_error("unsupported type");
                 }

src/ngraph/op/binary_convolution.cpp

@@ -114,18 +114,7 @@ void op::v1::BinaryConvolution::validate_and_infer_types()
         }
     }
 
-    element::Type result_et;
     PartialShape result_shape;
-
-    NODE_VALIDATION_CHECK(
-        this,
-        element::Type::merge(result_et, data_batch_et, filters_et),
-        "Element types for data batch and filters do not match (data batch element type: ",
-        data_batch_et,
-        ", filters element type: ",
-        filters_et,
-        ").");
-
     result_shape =
         infer_convolution_forward(this,
                                   data_batch_shape,
@@ -136,7 +125,7 @@ void op::v1::BinaryConvolution::validate_and_infer_types()
                                   m_strides,
                                   m_dilations);
 
-    set_output_type(0, result_et, result_shape);
+    set_output_type(0, data_batch_et, result_shape);
 }
 
 shared_ptr<Node> op::v1::BinaryConvolution::copy_with_new_args(const NodeVector& new_args) const

src/ngraph/op/constant.cpp

@@ -74,6 +74,9 @@ string op::Constant::convert_value_to_string(size_t index) const
     case element::Type_t::i16: rc = to_string(get_vector<int16_t>()[index]); break;
     case element::Type_t::i32: rc = to_string(get_vector<int32_t>()[index]); break;
     case element::Type_t::i64: rc = to_string(get_vector<int64_t>()[index]); break;
+    case element::Type_t::u1:
+        rc = to_string((get_vector<uint8_t>()[index / 8] >> (7 - (index % 8))) & 1);
+        break;
     case element::Type_t::u8: rc = to_string(get_vector<uint8_t>()[index]); break;
     case element::Type_t::u16: rc = to_string(get_vector<uint16_t>()[index]); break;
     case element::Type_t::u32: rc = to_string(get_vector<uint32_t>()[index]); break;
@@ -176,6 +179,7 @@ vector<string> op::Constant::get_value_strings() const
             rc.push_back(to_string(value));
         }
         break;
+    case element::Type_t::u1: throw runtime_error("unsupported type");
     case element::Type_t::undefined: throw runtime_error("unsupported type");
     case element::Type_t::dynamic: throw runtime_error("unsupported type");
     }
@@ -323,6 +327,7 @@ bool op::Constant::are_all_data_elements_bitwise_identical() const
         rc = test_bitwise_identical<uint64_t>(this);
         break;
     }
+    case element::Type_t::u1:
     case element::Type_t::undefined:
     case element::Type_t::dynamic: break;
     }

src/ngraph/op/constant.hpp

@@ -338,6 +338,7 @@ namespace ngraph
                 case element::Type_t::u64:
                     write_buffer<uint64_t, T>(target, source, target_element_count);
                     break;
+                case element::Type_t::u1: throw std::runtime_error("unsupported type");
                 case element::Type_t::undefined: throw std::runtime_error("unsupported type");
                 case element::Type_t::dynamic: throw std::runtime_error("unsupported type");
                 }

src/ngraph/op/experimental/range.cpp

@@ -230,6 +230,7 @@ void op::Range::validate_and_infer_types()
     case element::Type_t::u32: result_shape = infer_output_shape<uint32_t>(this, result_et); break;
     case element::Type_t::u64: result_shape = infer_output_shape<uint64_t>(this, result_et); break;
     case element::Type_t::dynamic: result_shape = PartialShape::dynamic(1); break;
+    case element::Type_t::u1:
     case element::Type_t::undefined:
     case element::Type_t::boolean:
         NODE_VALIDATION_CHECK(

src/ngraph/op/max.cpp

@@ -75,6 +75,7 @@ shared_ptr<Node> op::v0::Max::get_default_value() const
     case element::Type_t::u64:
         return make_constant_from_string(
             to_string(numeric_limits<uint64_t>::min()), get_element_type(), get_shape());
+    case element::Type_t::u1:
     case element::Type_t::undefined:
     case element::Type_t::dynamic:
     default: throw runtime_error("Max default value not defined for type");

src/ngraph/op/min.cpp

@@ -75,6 +75,7 @@ shared_ptr<Node> op::v0::Min::get_default_value() const
     case element::Type_t::u64:
         return make_constant_from_string(
             to_string(numeric_limits<uint64_t>::max()), get_element_type(), get_shape());
+    case element::Type_t::u1:
     case element::Type_t::undefined:
     case element::Type_t::dynamic:
     default: throw runtime_error("Min default value not defined for type");

src/ngraph/pass/constant_folding_arithmetic_reduction.cpp

@@ -189,6 +189,9 @@ static shared_ptr<op::Constant>
         NGRAPH_CHECK(false,
                      "Encountered 'dynamic' element type in fold_constant_arithmetic_reduction");
         break;
+    case element::Type_t::u1:
+        NGRAPH_CHECK(false, "Encountered 'u1' element type in fold_constant_arithmetic_reduction");
+        break;
     case element::Type_t::boolean:
         return fold_constant_arithmetic_reduction_helper<char>(constant, reduction_node);
     case element::Type_t::bf16:

src/ngraph/pass/constant_folding_binary.cpp

@@ -620,6 +620,9 @@ void pass::ConstantFolding::construct_constant_binary()
                 NGRAPH_CHECK(false,
                              "Encountered 'dynamic' element type in constant_binary_callback");
                 break;
+            case element::Type_t::u1:
+                NGRAPH_CHECK(false, "Encountered 'u1' element type in constant_binary_callback");
+                break;
             case element::Type_t::boolean:
                 replacement =
                     fold_constant_binary_helper<char>(a_match, b_match, binary_match, func);

src/ngraph/pass/constant_folding_broadcast.cpp

@@ -117,6 +117,9 @@ void pass::ConstantFolding::construct_constant_broadcast()
             NGRAPH_CHECK(false,
                          "Encountered 'dynamic' element type in constant_broadcast_callback");
             break;
+        case element::Type_t::u1:
+            NGRAPH_CHECK(false, "Encountered 'u1' element type in constant_broadcast_callback");
+            break;
         case element::Type_t::boolean:
             replacement = fold_constant_broadcast<char>(constant_match, broadcast_match, func);
             break;

src/ngraph/pass/constant_folding_concat.cpp

@@ -79,6 +79,9 @@ void pass::ConstantFolding::construct_constant_concat()
         case element::Type_t::dynamic:
             NGRAPH_CHECK(false, "Encountered 'dynamic' element type in fold_constant_concat");
             break;
+        case element::Type_t::u1:
+            NGRAPH_CHECK(false, "Encountered 'u1' element type in fold_constant_concat");
+            break;
         case element::Type_t::boolean:
             replacement = fold_constant_concat_helper<char>(concat_node);
             break;

src/ngraph/pass/constant_folding_convert.cpp

@@ -57,6 +57,9 @@ shared_ptr<op::Constant> fold_constant_convert_helper0(shared_ptr<op::Constant>
     case element::Type_t::dynamic:
         NGRAPH_CHECK(false, "Encountered 'dynamic' element type in fold_constant_convert");
         break;
+    case element::Type_t::u1:
+        NGRAPH_CHECK(false, "Encountered 'dynamic' element type in fold_constant_convert");
+        break;
     case element::Type_t::boolean:
         return fold_constant_convert_helper1<TI, char>(constant, output_element_type);
     case element::Type_t::bf16:
@@ -114,6 +117,9 @@ static shared_ptr<op::Constant> fold_constant_convert(shared_ptr<op::Constant> c
     case element::Type_t::dynamic:
         NGRAPH_CHECK(false, "Encountered 'dynamic' element type in fold_constant_convert");
         break;
+    case element::Type_t::u1:
+        NGRAPH_CHECK(false, "Encountered 'u1' element type in fold_constant_convert");
+        break;
     case element::Type_t::boolean:
         return fold_constant_convert_helper0<char>(constant, output_element_type);
     case element::Type_t::bf16:

src/ngraph/pass/constant_folding_dyn_broadcast.cpp

@@ -81,6 +81,9 @@ void pass::ConstantFolding::construct_constant_dyn_broadcast()
             NGRAPH_CHECK(false,
                          "Encountered 'dynamic' element type in constant_dyn_broadcast_callback");
             break;
+        case element::Type_t::u1:
+            NGRAPH_CHECK(false, "Encountered 'u1' element type in constant_dyn_broadcast_callback");
+            break;
         case element::Type_t::boolean:
             replacement = fold_constant_dyn_broadcast<char>(
                 constant_arg_match, constant_shape_match, constant_axes_match);

src/ngraph/pass/constant_folding_dyn_reshape.cpp

@@ -79,6 +79,9 @@ void pass::ConstantFolding::construct_constant_dyn_reshape()
             NGRAPH_CHECK(false,
                          "Encountered 'dynamic' element type in constant_dyn_reshape_callback");
             break;
+        case element::Type_t::u1:
+            NGRAPH_CHECK(false, "Encountered 'u1' element type in constant_dyn_reshape_callback");
+            break;
         case element::Type_t::boolean:
             replacement = fold_constant_dyn_reshape<char>(constant_data_match, dyn_reshape_match);
             break;

src/ngraph/pass/constant_folding_dyn_slice.cpp

@@ -114,6 +114,9 @@ void pass::ConstantFolding::construct_constant_dyn_slice()
         case element::Type_t::dynamic:
             NGRAPH_CHECK(false, "Encountered 'dynamic' element type in fold_constant_dyn_slice");
             break;
+        case element::Type_t::u1:
+            NGRAPH_CHECK(false, "Encountered 'u1' element type in fold_constant_dyn_slice");
+            break;
         case element::Type_t::boolean:
             replacement =
                 fold_constant_dyn_slice<char>(data_node, lb_node, ub_node, strides_node, dyn_slice);

src/ngraph/pass/constant_folding_gather.cpp

@@ -81,6 +81,7 @@ static shared_ptr<op::Constant> fold_constant_gather(const shared_ptr<op::Consta
     case element::Type_t::f64:
     case element::Type_t::i8:
     case element::Type_t::i16:
+    case element::Type_t::u1:
     case element::Type_t::u8:
     case element::Type_t::u16:
     case element::Type_t::u32:
@@ -134,6 +135,9 @@ void pass::ConstantFolding::construct_constant_gather()
         case element::Type_t::dynamic:
             NGRAPH_CHECK(false, "Encountered 'dynamic' element type in constant_gather_callback");
             break;
+        case element::Type_t::u1:
+            NGRAPH_CHECK(false, "Encountered 'u1' element type in constant_gather_callback");
+            break;
         case element::Type_t::boolean:
             replacement = fold_constant_gather<char>(data, indices, gather);
             break;

src/ngraph/pass/constant_folding_pad.cpp

@@ -100,6 +100,9 @@ void pass::ConstantFolding::construct_constant_pad()
         case element::Type_t::dynamic:
             NGRAPH_CHECK(false, "Encountered 'dynamic' element type in constant_pad_callback");
             break;
+        case element::Type_t::u1:
+            NGRAPH_CHECK(false, "Encountered 'u1' element type in constant_pad_callback");
+            break;
         case element::Type_t::boolean:
             replacement = fold_constant_pad<char>(constant_match, pad_match, func);
             break;

src/ngraph/pass/constant_folding_range.cpp

@@ -68,6 +68,9 @@ void pass::ConstantFolding::construct_constant_range()
         case element::Type_t::dynamic:
             NGRAPH_CHECK(false, "Encountered 'dynamic' element type in constant_range_callback");
             break;
+        case element::Type_t::u1:
+            NGRAPH_CHECK(false, "Encountered 'u1' element type in constant_range_callback");
+            break;
         case element::Type_t::boolean:
             replacement = fold_constant_range<char>(start_node, step_node, range);
             break;

src/ngraph/pass/constant_folding_reshape.cpp

@@ -87,6 +87,9 @@ void pass::ConstantFolding::construct_constant_reshape()
         case element::Type_t::dynamic:
             NGRAPH_CHECK(false, "Encountered 'dynamic' element type in constant_reshape_callback");
             break;
+        case element::Type_t::u1:
+            NGRAPH_CHECK(false, "Encountered 'u1' element type in constant_reshape_callback");
+            break;
         case element::Type_t::boolean:
             replacement = fold_constant_reshape<char>(constant_match, reshape_match, func);
             break;

src/ngraph/pass/constant_folding_reverse.cpp

@@ -52,6 +52,9 @@ static shared_ptr<op::Constant> fold_constant_reverse(shared_ptr<op::Constant> c
     case element::Type_t::dynamic:
         NGRAPH_CHECK(false, "Encountered 'dynamic' element type in fold_constant_convert");
         break;
+    case element::Type_t::u1:
+        NGRAPH_CHECK(false, "Encountered 'u1' element type in fold_constant_convert");
+        break;
     case element::Type_t::boolean:
         return fold_constant_reverse_helper<char>(constant, reversed_axes);
     case element::Type_t::bf16:

src/ngraph/pass/constant_folding_select.cpp

@@ -72,6 +72,9 @@ void pass::ConstantFolding::construct_constant_select()
         case element::Type_t::dynamic:
             NGRAPH_CHECK(false, "Encountered 'dynamic' element type in constant_select_callback");
             break;
+        case element::Type_t::u1:
+            NGRAPH_CHECK(false, "Encountered 'u1' element type in constant_select_callback");
+            break;
         case element::Type_t::boolean:
             replacement = fold_constant_select<char>(selection_node, t_node, f_node, select);
             break;

src/ngraph/pass/constant_folding_slice.cpp

@@ -67,6 +67,9 @@ void pass::ConstantFolding::construct_constant_slice()
         case element::Type_t::dynamic:
             NGRAPH_CHECK(false, "Encountered 'dynamic' element type in fold_constant_slice");
             break;
+        case element::Type_t::u1:
+            NGRAPH_CHECK(false, "Encountered 'u1' element type in fold_constant_slice");
+            break;
         case element::Type_t::boolean:
             replacement = fold_constant_slice<char>(data_node, slice);
             break;

src/ngraph/pass/constant_folding_squeeze.cpp

@@ -61,6 +61,9 @@ void pass::ConstantFolding::construct_constant_squeeze()
         case element::Type_t::dynamic:
             NGRAPH_CHECK(false, "Encountered 'dynamic' element type in constant_squeeze_callback");
             break;
+        case element::Type_t::u1:
+            NGRAPH_CHECK(false, "Encountered 'u1' element type in constant_squeeze_callback");
+            break;
         case element::Type_t::boolean:
             replacement = fold_constant_squeeze<char>(constant_match, squeeze_match);
             break;

src/ngraph/pass/constant_folding_transpose.cpp

@@ -75,6 +75,9 @@ void pass::ConstantFolding::construct_constant_transpose()
             NGRAPH_CHECK(false,
                          "Encountered 'dynamic' element type in constant_transpose_callback");
             break;
+        case element::Type_t::u1:
+            NGRAPH_CHECK(false, "Encountered 'u1' element type in constant_transpose_callback");
+            break;
         case element::Type_t::boolean:
             replacement = fold_constant_transpose<char>(
                 constant_data_match, constant_perm_match, transpose_match);

src/ngraph/pass/constant_folding_unary.cpp

@@ -169,6 +169,9 @@ void pass::ConstantFolding::construct_constant_unary()
         case element::Type_t::dynamic:
             NGRAPH_CHECK(false, "Encountered 'dynamic' element type in constant_unary_callback");
             break;
+        case element::Type_t::u1:
+            NGRAPH_CHECK(false, "Encountered 'u1' element type in constant_unary_callback");
+            break;
         case element::Type_t::boolean:
             replacement = fold_constant_unary<char>(constant_match, unary_match, func);
             break;

src/ngraph/pass/constant_folding_unsqueeze.cpp

@@ -62,6 +62,9 @@ void pass::ConstantFolding::construct_constant_unsqueeze()
             NGRAPH_CHECK(false,
                          "Encountered 'dynamic' element type in constant_unsqueeze_callback");
             break;
+        case element::Type_t::u1:
+            NGRAPH_CHECK(false, "Encountered 'u1' element type in constant_unsqueeze_callback");
+            break;
         case element::Type_t::boolean:
             replacement = fold_constant_unsqueeze<char>(constant_match, unsqueeze_match);
             break;

src/ngraph/pass/dyn_elimination.cpp

@@ -428,6 +428,7 @@ void pass::DynElimination::construct_range()
         case element::Type_t::u64:
             replacement = make_range_replacement<uint64_t>(et, shape, start_arg, step_arg);
             break;
+        case element::Type_t::u1:
         case element::Type_t::undefined:
         case element::Type_t::dynamic:
         case element::Type_t::boolean:

src/ngraph/runtime/cpu/builder/random_uniform.cpp

@@ -112,6 +112,9 @@ namespace ngraph
                     NGRAPH_CHECK(false,
                                  "Encountered 'dynamic' element type in fold_constant_convert");
                     break;
+                case element::Type_t::u1:
+                    NGRAPH_CHECK(false, "Encountered 'u1' element type in fold_constant_convert");
+                    break;
                 case element::Type_t::boolean:
                     functor = prepare_functor<char>(node, args, out, external_function);
                     break;

src/ngraph/runtime/cpu/cpu_external_function.cpp

@@ -1376,6 +1376,7 @@ static void dump_one_kernel_with_type(runtime::cpu::CPU_DebugTracer& debug_trace
     case element::Type_t::f64:
     case element::Type_t::i16:
     case element::Type_t::i64:
+    case element::Type_t::u1:
     case element::Type_t::u16:
     case element::Type_t::u32:
     case element::Type_t::u64:

src/ngraph/runtime/cpu/pass/cpu_post_layout_optimizations.cpp

@@ -439,6 +439,10 @@ bool ngraph::runtime::cpu::pass::CPUConvertLayoutConstantFolding::run_on_functio
                         false,
                         "Encountered 'dynamic' element type in construct_constant_convertlayout");
                     break;
+                case element::Type_t::u1:
+                    NGRAPH_CHECK(
+                        false, "Encountered 'u1' element type in construct_constant_convertlayout");
+                    break;
                 case element::Type_t::boolean:
                     replacement = fold_constant_convertlayout_helper<char>(
                         m_input, m_convertlayout, input_md, output_md);

src/ngraph/runtime/generic_cpu/gcpu_executable.cpp

@@ -230,6 +230,7 @@ void runtime::gcpu::GCPUExecutable::generate_calls(const element::Type& type,
     case element::Type_t::u64: op_engine<uint64_t>(op, out, in); break;
     case element::Type_t::undefined:
     case element::Type_t::dynamic:
+    case element::Type_t::u1:
     case element::Type_t::bf16:
     case element::Type_t::f16:
         ss << "unsupported element type " << type << " op " << op.get_node()->get_name();

src/ngraph/runtime/generic_cpu/gcpu_executable.hpp

@@ -626,6 +626,7 @@ private:
                 break;
             case element::Type_t::undefined:
             case element::Type_t::dynamic:
+            case element::Type_t::u1:
             case element::Type_t::bf16:
             case element::Type_t::f16:
                 ss << "unsupported element type " << type << " op Convert";

src/ngraph/runtime/interpreter/int_executable.cpp

@@ -232,6 +232,7 @@ void runtime::interpreter::INTExecutable::generate_calls(const element::Type& ty
     case element::Type_t::u64: op_engine<uint64_t>(op, out, in); break;
     case element::Type_t::undefined:
     case element::Type_t::dynamic:
+    case element::Type_t::u1:
     case element::Type_t::bf16:
     case element::Type_t::f16:
         ss << "unsupported element type " << type << " op " << op.get_node()->get_name();

src/ngraph/runtime/interpreter/int_executable.hpp

@@ -672,6 +672,7 @@ private:
                 break;
             case element::Type_t::undefined:
             case element::Type_t::dynamic:
+            case element::Type_t::u1:
             case element::Type_t::bf16:
             case element::Type_t::f16:
                 ss << "unsupported element type " << type << " op Convert";

src/ngraph/type/element_type.cpp

@@ -34,6 +34,7 @@ NGRAPH_API const element::Type element::i8(element::Type_t::i8);
 NGRAPH_API const element::Type element::i16(element::Type_t::i16);
 NGRAPH_API const element::Type element::i32(element::Type_t::i32);
 NGRAPH_API const element::Type element::i64(element::Type_t::i64);
+NGRAPH_API const element::Type element::u1(element::Type_t::u1);
 NGRAPH_API const element::Type element::u8(element::Type_t::u8);
 NGRAPH_API const element::Type element::u16(element::Type_t::u16);
 NGRAPH_API const element::Type element::u32(element::Type_t::u32);
@@ -80,6 +81,7 @@ static const map<element::Type_t, const TypeInfo>& get_type_info_map()
         {element::Type_t::i16, TypeInfo(16, false, true, false, "int16_t", "i16")},
         {element::Type_t::i32, TypeInfo(32, false, true, true, "int32_t", "i32")},
         {element::Type_t::i64, TypeInfo(64, false, true, false, "int64_t", "i64")},
+        {element::Type_t::u1, TypeInfo(1, false, false, false, "uint8_t", "u1")},
         {element::Type_t::u8, TypeInfo(8, false, false, true, "uint8_t", "u8")},
         {element::Type_t::u16, TypeInfo(16, false, false, false, "uint16_t", "u16")},
         {element::Type_t::u32, TypeInfo(32, false, false, false, "uint32_t", "u32")},
@@ -100,6 +102,7 @@ std::vector<const element::Type*> element::Type::get_known_types()
                                             &element::i16,
                                             &element::i32,
                                             &element::i64,
+                                            &element::u1,
                                             &element::u8,
                                             &element::u16,
                                             &element::u32,

src/ngraph/type/element_type.hpp

@@ -49,6 +49,7 @@ namespace ngraph
             i16,
             i32,
             i64,
+            u1,
             u8,
             u16,
             u32,
@@ -139,6 +140,7 @@ namespace ngraph
         extern NGRAPH_API const Type i16;
         extern NGRAPH_API const Type i32;
         extern NGRAPH_API const Type i64;
+        extern NGRAPH_API const Type u1;
         extern NGRAPH_API const Type u8;
         extern NGRAPH_API const Type u16;
         extern NGRAPH_API const Type u32;

src/tools/nbench/benchmark_utils.cpp

@@ -100,6 +100,7 @@ void random_init(shared_ptr<runtime::Tensor> tensor)
     case element::Type_t::u64: init_int_tensor<uint64_t>(tensor, 0, 1); break;
     case element::Type_t::undefined:
     case element::Type_t::dynamic:
+    case element::Type_t::u1:
     case element::Type_t::bf16:
     case element::Type_t::f16:
     default: throw runtime_error("unsupported type");

test/CMakeLists.txt

@@ -54,6 +54,7 @@ set(SRC
     constant_folding.cpp
     concat_fusion.cpp
     control_dependencies.cpp
+    convert_u1_to_string.cpp
     coordinate.cpp
     copy.cpp
     cpio.cpp

test/convert_u1_to_string.cpp

+//*****************************************************************************
+// Copyright 2019 Intel Corporation
+//
+// 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.
+//*****************************************************************************
+
+#include "gtest/gtest.h"
+#include "ngraph/ngraph.hpp"
+#include "util/all_close_f.hpp"
+#include "util/test_tools.hpp"
+
+using namespace ngraph;
+using namespace std;
+
+TEST(convert_u1_to_string, convert_u1_to_string)
+{
+    vector<uint8_t> values{171, 16};
+    auto constant = make_shared<op::Constant>(element::u1, Shape{12}, &values[0]);
+
+    vector<string> ref{"1", "0", "1", "0", "1", "0", "1", "1", "0", "0", "0", "1"};
+    for (size_t i = 0; i < 12; ++i)
+    {
+        ASSERT_EQ(constant->convert_value_to_string(i), ref[i]);
+    }
+}
\ No newline at end of file