COMPMID-2193: Improve permute documentation.

Change-Id: I64553718572296e4acfa5de3f1f8dceaca81116f
Signed-off-by: Pablo Tello <pablo.tello@arm.com>
Reviewed-on: https://review.mlplatform.org/c/1474
Reviewed-by: Michele Di Giorgio <michele.digiorgio@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Georgios Pinitas <georgios.pinitas@arm.com>
Tested-by: Arm Jenkins <bsgcomp@arm.com>

1 files changed, 127 insertions, 0 deletions

diff --git a/examples/neon_permute.cpp b/examples/neon_permute.cpp
new file mode 100644
index 0000000000..e2030b7ddc
--- /dev/null
+++ b/examples/neon_permute.cpp
@@ -0,0 +1,127 @@
+/*
+ * Copyright (c) 2019 ARM Limited.
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#include "arm_compute/runtime/NEON/NEFunctions.h"
+
+#include "arm_compute/core/Types.h"
+#include "utils/Utils.h"
+
+using namespace arm_compute;
+using namespace utils;
+
+class NeonPermuteExample : public Example
+{
+public:
+    NeonPermuteExample() = default;
+
+    bool do_setup(int, char **) override
+    {
+        // Initialise shapes
+        init_tensor(TensorShape(8U, 4U, 2U), tensor_nchw, DataType::U8, DataLayout::NCHW);
+        init_tensor(TensorShape(2U, 8U, 4U), tensor_nhwc, DataType::U8, DataLayout::NHWC);
+        init_tensor(TensorShape(8U, 4U, 2U), tensor_nchw_result, DataType::U8, DataLayout::NCHW);
+
+        // Create the permutation vector to turn a NCHW tensor to NHWC.
+        // The input tensor is NCHW, which means that the fastest changing coordinate is W=8U.
+        // For permutation vectors the fastest changing coordinate is the one on the left too.
+        // Each element in the permutation vector specifies a mapping from the source tensor to the destination one, thus if we
+        // use 2U in the permutation vector's first element we are telling the function to move the channels to the fastest
+        // changing coordinate in the destination tensor.
+
+        const PermutationVector vector_nchw_to_nhwc(2U, 0U, 1U);
+        permute_nhwc.configure(&tensor_nchw, &tensor_nhwc, vector_nchw_to_nhwc);
+
+        // Allocate and fill tensors
+        tensor_nhwc.allocator()->allocate();
+        tensor_nchw.allocator()->allocate();
+        fill_tensor(tensor_nchw);
+
+        // Demostrate autoconfigure for the output tensor
+        const PermutationVector vector_nhwc_to_nchw(1U, 2U, 0U);
+        permute_nchw.configure(&tensor_nhwc, &tensor_nchw_result, vector_nhwc_to_nchw);
+        tensor_nchw_result.allocator()->allocate();
+
+        return true;
+    }
+    void do_run() override
+    {
+        permute_nhwc.run();
+        permute_nchw.run();
+    }
+    void do_teardown() override
+    {
+#if ARM_COMPUTE_DEBUG_ENABLED
+        std::cout << "Tensor NCHW" << std::endl;
+        tensor_nchw.print(std::cout);
+        std::cout << "Tensor NHWC" << std::endl;
+        tensor_nhwc.print(std::cout);
+#endif
+    }
+
+private:
+    void validate_result(const Tensor &reference, const Tensor &result)
+    {
+        Window window;
+        window.use_tensor_dimensions(reference.info()->tensor_shape());
+        Iterator ref_it(&reference, window);
+        Iterator res_it(&result, window);
+        execute_window_loop(window, [&](const Coordinates &)
+        {
+            assert(*reinterpret_cast<unsigned char *>(ref_it.ptr()) == *reinterpret_cast<unsigned char *>(res_it.ptr()));
+        },
+        ref_it, res_it);
+    }
+
+    void fill_tensor(Tensor &tensor)
+    {
+        Window window;
+        window.use_tensor_dimensions(tensor.info()->tensor_shape());
+        Iterator      tensor_it(&tensor, window);
+        unsigned char val(0);
+        execute_window_loop(window, [&](const Coordinates &)
+        {
+            *reinterpret_cast<unsigned char *>(tensor_it.ptr()) = val++;
+        },
+        tensor_it);
+    }
+    void init_tensor(const TensorShape shape, Tensor &tensor, DataType type, DataLayout layout)
+    {
+        tensor.allocator()->init(TensorInfo(shape, 1, type).set_data_layout(layout));
+    }
+
+    Tensor    tensor_nchw{};
+    Tensor    tensor_nhwc{};
+    Tensor    tensor_nchw_result{};
+    NEPermute permute_nhwc{};
+    NEPermute permute_nchw{};
+};
+
+/** Main program that instantiates a permute function example.
+ *
+ * @param[in] argc Number of arguments
+ * @param[in] argv Arguments
+ */
+int main(int argc, char **argv)
+{
+    return utils::run_example<NeonPermuteExample>(argc, argv);
+}