quantize tie half to even

src/include/migraphx/op/quantizelinear.hpp

@@ -63,6 +63,7 @@ struct quantizelinear
 
     argument compute(const shape& output_shape, std::vector<argument> args) const
     {
+        auto round_even = [](auto v) { return v - remainder(v, 1.0); };
         auto x          = args.at(0);
         auto y_scale    = args.at(1);
         std::vector<int8_t> zeros(output_shape.bytes(), 0);
@@ -79,7 +80,7 @@ struct quantizelinear
                 auto min_value   = std::numeric_limits<quant_type>::min();
                 auto max_value   = std::numeric_limits<quant_type>::max();
                 par_for(output_shape.elements(), [&](auto i) {
-                    int64_t quantized = static_cast<int64_t>(std::round(input[i] / scales[i])) +
+                    int64_t quantized = static_cast<int64_t>(round_even(input[i] / scales[i])) +
                                         static_cast<int64_t>(zero_pts[i]);
                     output[i] = std::max(static_cast<int64_t>(min_value),
                                          std::min(static_cast<int64_t>(max_value), quantized));

src/include/migraphx/op/round.hpp

@@ -35,7 +35,7 @@ struct round : unary<round>
 {
     auto apply() const
     {
-        return [](auto x) { return std::round(x); };
+        return [](auto v) { return v - remainder(v, 1.0); };
     }
 };
 

test/onnx/gen_onnx.py

@@ -5495,6 +5495,24 @@ def prelu_brcst_test():
     return ([node], [arg0, arg1], [arg_out])
 
 
+@onnx_test()
+def qlinear_test():
+    x = helper.make_tensor_value_info('X', TensorProto.FLOAT, [6])
+
+    sc_y = helper.make_tensor('y_scale', TensorProto.FLOAT, [], [2])
+    zero_pt_y = helper.make_tensor('y_zero_point', TensorProto.UINT8, [],
+                                   [128])
+
+    y = helper.make_tensor_value_info('Y', TensorProto.UINT8, [6])
+
+    node = onnx.helper.make_node(
+        'QuantizeLinear',
+        inputs=['X'],
+        outputs=['Y'],
+    )
+    return ([node], [x], [y], [sc_y, zero_pt_y])
+
+
 @onnx_test()
 def qlinearadd_test():
     a = helper.make_tensor_value_info('A', TensorProto.UINT8, [64])

test/onnx/verify_onnx.cpp

@@ -1344,6 +1344,27 @@ TEST_CASE(nonzero_test)
     EXPECT(migraphx::verify::verify_rms_range(result_vector, gold));
 }
 
+TEST_CASE(qlinear_test)
+{
+    // https://xadupre.github.io/draft/onnx/onnx_doc_folder/onnx__QuantizeLinear.html
+    migraphx::program p = migraphx::parse_onnx("qlinear_test.onnx");
+    p.compile(migraphx::make_target("ref"));
+
+    migraphx::shape x{migraphx::shape::float_type, {6}};
+    std::vector<float> data_x = {0, 2, 3, 1000, -254, -1000};
+
+    migraphx::parameter_map pp;
+    pp["X"]     = migraphx::argument(x, data_x.data());
+    auto result = p.eval(pp).back();
+
+    std::vector<uint8_t> result_vector;
+    result.visit([&](auto output) { result_vector.assign(output.begin(), output.end()); });
+
+    std::vector<uint8_t> gold = {128, 129, 130, 255, 1, 0};
+
+    EXPECT(migraphx::verify::verify_rms_range(result_vector, gold));
+}
+
 TEST_CASE(qlinearadd_test)
 {
     // github.com/microsoft/onnxruntime/blob/main/docs/ContribOperators.md#com.microsoft.QLinearAdd