Export ROCm/rocm-libraries@2d4a3223cb

include/ck_tile/host/reference/reference_softmax.hpp

@@ -0,0 +1,89 @@
+// 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 InputType, typename ComputeType, typename OutputType = ComputeType>
+CK_TILE_HOST void
+reference_softmax(const HostTensor<InputType>& x, HostTensor<OutputType>& y, index_t dim = -1)
+{
+    index_t rank = x.get_num_of_dimension();
+    assert(static_cast<std::size_t>(rank) == y.get_num_of_dimension());
+    assert(dim == -1 || dim < rank);
+
+    index_t target_dim  = dim == -1 ? (rank - 1) : dim;
+    index_t softmax_len = x.get_length(target_dim);
+    index_t n_parallel  = x.get_element_size() / softmax_len;
+    auto x_len          = x.get_lengths();
+
+    auto f = [&](auto i_element) {
+        std::vector<size_t> coord = [&]() {
+            std::vector<size_t> t_(rank, 0);
+            size_t r = i_element;
+            for(index_t i = rank - 1; i >= 0; i--)
+            {
+                if(i == target_dim)
+                    continue;
+                t_[i] = r % x_len[i];
+                r     = r / x_len[i];
+            }
+            return t_;
+        }();
+
+        ComputeType v_max = -ck_tile::numeric<ComputeType>::infinity();
+
+        // compute max
+        for(auto idx = 0; idx < softmax_len; idx++)
+        {
+            auto c_               = coord;
+            c_[target_dim]        = idx;
+            const ComputeType v_x = ck_tile::type_convert<ComputeType>(x(c_));
+            v_max                 = v_max < v_x ? v_x : v_max;
+        }
+
+        ComputeType v_exp_sum = static_cast<ComputeType>(0);
+
+        // sum
+        for(auto idx = 0; idx < softmax_len; idx++)
+        {
+            auto c_        = coord;
+            c_[target_dim] = idx;
+
+            const ComputeType v_x = ck_tile::type_convert<ComputeType>(x(c_));
+
+            v_exp_sum += ck_tile::exp(v_x - v_max);
+        }
+
+        // elementwise
+        for(auto idx = 0; idx < softmax_len; idx++)
+        {
+            auto c_        = coord;
+            c_[target_dim] = idx;
+
+            const ComputeType v_x = ck_tile::type_convert<ComputeType>(x(c_));
+
+            auto out = ck_tile::exp(v_x - v_max) / v_exp_sum;
+
+            y(c_) = ck_tile::type_convert<OutputType>(out);
+        }
+    };
+
+    make_ParallelTensorFunctor(f, n_parallel)(std::thread::hardware_concurrency());
+}
+
+template <typename InputType, typename ComputeType, typename OutputType = ComputeType>
+CK_TILE_HOST auto reference_softmax(const HostTensor<InputType>& x, index_t dim = -1)
+{
+    HostTensor<OutputType> y(x.get_lengths(), x.get_strides());
+
+    reference_softmax<InputType, ComputeType, OutputType>(x, y, dim);
+
+    return y;
+}
+} // namespace ck_tile