Move reference to host/reference

include/ck_tile/host/reference/reference_sinkhorn.hpp

@@ -0,0 +1,81 @@
+// Copyright (c) Advanced Micro Devices, Inc., or its affiliates.
+// SPDX-License-Identifier: MIT
+
+#pragma once
+
+#include "ck_tile/core.hpp"
+#include "ck_tile/host/host_tensor.hpp"
+#include <thread>
+
+namespace ck_tile {
+
+template <typename ComputeDataType>
+void sinkhorn_knopp_ref_single_iter(HostTensor<ComputeDataType>& c_n_n,
+                                    HostTensor<ComputeDataType>& acc_n)
+{
+    const index_t input_n = acc_n.get_length(0);
+
+    // Sum and scale rowwise
+    for(index_t i = 0; i < input_n; ++i)
+    {
+        acc_n(i) = 0;
+        for(index_t j = 0; j < input_n; ++j)
+        {
+            acc_n(i) += c_n_n(i, j);
+        }
+        for(index_t j = 0; j < input_n; ++j)
+        {
+            c_n_n(i, j) /= acc_n(i);
+        }
+    }
+
+    // Repeat columnwise
+    for(index_t i = 0; i < input_n; ++i)
+    {
+        acc_n(i) = 0;
+        for(index_t j = 0; j < input_n; ++j)
+        {
+            acc_n(i) += c_n_n(j, i);
+        }
+        for(index_t j = 0; j < input_n; ++j)
+        {
+            c_n_n(j, i) /= acc_n(i);
+        }
+    }
+}
+
+template <typename XDataType, typename ComputeDataType, typename YDataType>
+void sinkhorn_knopp_ref(const HostTensor<XDataType>& x_n_n,
+                        HostTensor<YDataType>& y_n_n,
+                        const int n_iter)
+{
+    const index_t input_n = x_n_n.get_length(0);
+    HostTensor<ComputeDataType> c_n_n({input_n, input_n}, {1, input_n});
+    HostTensor<ComputeDataType> acc_n({input_n}, {1});
+
+    // First apply exp to make input nonnegative
+    for(index_t i = 0; i < input_n; ++i)
+    {
+        for(index_t j = 0; j < input_n; ++j)
+        {
+            c_n_n(i, j) = exp(type_convert<ComputeDataType>(x_n_n(i, j)));
+        }
+    }
+
+    // Iterate normalization on rows and columns
+    for(auto it = 0; it < n_iter; ++it)
+    {
+        sinkhorn_knopp_ref_single_iter(c_n_n, c_n_n);
+    }
+
+    // Copy and cast to output type
+    for(index_t i = 0; i < input_n; ++i)
+    {
+        for(index_t j = 0; j < input_n; ++j)
+        {
+            y_n_n(i, j) = type_convert<YDataType>(c_n_n(i, j));
+        }
+    }
+}
+
+} // namespace ck_tile