COMPMID-344 Updated doxygen

Change-Id: I32f7b84daa560e460b77216add529c8fa8b327ae

1 files changed, 252 insertions, 0 deletions

diff --git a/src/core/NEON/kernels/NEHistogramKernel.cpp b/src/core/NEON/kernels/NEHistogramKernel.cpp
new file mode 100644
index 0000000000..9e967ec4f5
--- /dev/null
+++ b/src/core/NEON/kernels/NEHistogramKernel.cpp
@@ -0,0 +1,252 @@
+/*
+ * Copyright (c) 2016, 2017 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/core/NEON/kernels/NEHistogramKernel.h"
+
+#include "arm_compute/core/Error.h"
+#include "arm_compute/core/Helpers.h"
+#include "arm_compute/core/IDistribution1D.h"
+#include "arm_compute/core/ITensor.h"
+#include "arm_compute/core/TensorInfo.h"
+#include "arm_compute/core/Types.h"
+#include "arm_compute/core/Window.h"
+
+#include <algorithm>
+#include <arm_neon.h>
+#include <array>
+
+using namespace arm_compute;
+
+namespace arm_compute
+{
+class Coordinates;
+} // namespace arm_compute
+
+inline void NEHistogramKernel::merge_histogram(uint32_t *global_hist, const uint32_t *local_hist, size_t bins)
+{
+    std::lock_guard<std::mutex> lock(_hist_mtx);
+
+    const unsigned int v_end = (bins / 4) * 4;
+
+    for(unsigned int b = 0; b < v_end; b += 4)
+    {
+        const uint32x4_t tmp_global = vld1q_u32(global_hist + b);
+        const uint32x4_t tmp_local  = vld1q_u32(local_hist + b);
+        vst1q_u32(global_hist + b, vaddq_u32(tmp_global, tmp_local));
+    }
+
+    for(unsigned int b = v_end; b < bins; ++b)
+    {
+        global_hist[b] += local_hist[b];
+    }
+}
+
+NEHistogramKernel::NEHistogramKernel()
+    : _func(nullptr), _input(nullptr), _output(nullptr), _local_hist(nullptr), _window_lut(nullptr), _hist_mtx()
+{
+}
+
+void NEHistogramKernel::histogram_U8(Window win)
+{
+    ARM_COMPUTE_ERROR_ON(_output->buffer() == nullptr);
+
+    const size_t          bins       = _output->num_bins();
+    const int32_t         offset     = _output->offset();
+    const uint32_t        offrange   = offset + _output->range();
+    const uint32_t *const w_lut      = _window_lut;
+    uint32_t *const       local_hist = _local_hist + win.thread_id() * bins;
+
+    // Clear local_histogram
+    std::fill_n(local_hist, bins, 0);
+
+    auto update_local_hist = [&](uint8_t p)
+    {
+        if(offset <= p && p < offrange)
+        {
+            ++local_hist[w_lut[p]];
+        }
+    };
+
+    const unsigned int x_start = win.x().start();
+    const unsigned int x_end   = win.x().end();
+
+    // Handle X dimension manually to split into two loops
+    // First one will use vector operations, second one processes the left over
+    // pixels
+    win.set(Window::DimX, Window::Dimension(0, 1, 1));
+
+    Iterator input(_input, win);
+
+    // Calculate local histogram
+    execute_window_loop(win, [&](const Coordinates &)
+    {
+        unsigned int x = x_start;
+
+        // Vector loop
+        for(; x <= x_end - 8; x += 8)
+        {
+            const uint8x8_t pixels = vld1_u8(input.ptr() + x);
+
+            update_local_hist(vget_lane_u8(pixels, 0));
+            update_local_hist(vget_lane_u8(pixels, 1));
+            update_local_hist(vget_lane_u8(pixels, 2));
+            update_local_hist(vget_lane_u8(pixels, 3));
+            update_local_hist(vget_lane_u8(pixels, 4));
+            update_local_hist(vget_lane_u8(pixels, 5));
+            update_local_hist(vget_lane_u8(pixels, 6));
+            update_local_hist(vget_lane_u8(pixels, 7));
+        }
+
+        // Process leftover pixels
+        for(; x < x_end; ++x)
+        {
+            update_local_hist(input.ptr()[x]);
+        }
+    },
+    input);
+
+    // Merge histograms
+    merge_histogram(_output->buffer(), local_hist, bins);
+}
+
+void NEHistogramKernel::histogram_fixed_U8(Window win)
+{
+    ARM_COMPUTE_ERROR_ON(_output->buffer() == nullptr);
+
+    std::array<uint32_t, _max_range_size> local_hist{ { 0 } };
+
+    const unsigned int x_start = win.x().start();
+    const unsigned int x_end   = win.x().end();
+
+    // Handle X dimension manually to split into two loops
+    // First one will use vector operations, second one processes the left over
+    // pixels
+    win.set(Window::DimX, Window::Dimension(0, 1, 1));
+
+    Iterator input(_input, win);
+
+    // Calculate local histogram
+    execute_window_loop(win, [&](const Coordinates &)
+    {
+        unsigned int x = x_start;
+
+        // Vector loop
+        for(; x <= x_end - 8; x += 8)
+        {
+            const uint8x8_t pixels = vld1_u8(input.ptr() + x);
+
+            ++local_hist[vget_lane_u8(pixels, 0)];
+            ++local_hist[vget_lane_u8(pixels, 1)];
+            ++local_hist[vget_lane_u8(pixels, 2)];
+            ++local_hist[vget_lane_u8(pixels, 3)];
+            ++local_hist[vget_lane_u8(pixels, 4)];
+            ++local_hist[vget_lane_u8(pixels, 5)];
+            ++local_hist[vget_lane_u8(pixels, 6)];
+            ++local_hist[vget_lane_u8(pixels, 7)];
+        }
+
+        // Process leftover pixels
+        for(; x < x_end; ++x)
+        {
+            ++local_hist[input.ptr()[x]];
+        }
+    },
+    input);
+
+    // Merge histograms
+    merge_histogram(_output->buffer(), local_hist.data(), _max_range_size);
+}
+
+void NEHistogramKernel::calculate_window_lut() const
+{
+    const int32_t  offset = _output->offset();
+    const size_t   bins   = _output->num_bins();
+    const uint32_t range  = _output->range();
+
+    std::fill_n(_window_lut, offset, 0);
+
+    for(unsigned int p = offset; p < _max_range_size; ++p)
+    {
+        _window_lut[p] = ((p - offset) * bins) / range;
+    }
+}
+
+void NEHistogramKernel::configure(const IImage *input, IDistribution1D *output, uint32_t *local_hist, uint32_t *window_lut)
+{
+    ARM_COMPUTE_ERROR_ON_TENSOR_NOT_2D(input);
+    ARM_COMPUTE_ERROR_ON_DATA_TYPE_CHANNEL_NOT_IN(input, 1, DataType::U8);
+    ARM_COMPUTE_ERROR_ON(nullptr == output);
+    ARM_COMPUTE_ERROR_ON(nullptr == local_hist);
+    ARM_COMPUTE_ERROR_ON(nullptr == window_lut);
+
+    _input      = input;
+    _output     = output;
+    _local_hist = local_hist;
+    _window_lut = window_lut;
+
+    //Check offset
+    ARM_COMPUTE_ERROR_ON_MSG(0 > _output->offset() || _output->offset() > static_cast<int32_t>(_max_range_size), "Offset is larger than the image value range.");
+
+    //Check range
+    ARM_COMPUTE_ERROR_ON_MSG(static_cast<int32_t>(_output->range()) > static_cast<int32_t>(_max_range_size) /* max range */, "Range larger than the image value range.");
+
+    // Calculate LUT
+    calculate_window_lut();
+
+    // Set appropriate function
+    _func = &NEHistogramKernel::histogram_U8;
+
+    constexpr unsigned int num_elems_processed_per_iteration = 1;
+
+    Window win = calculate_max_window(*input->info(), Steps(num_elems_processed_per_iteration));
+
+    INEKernel::configure(win);
+}
+
+void NEHistogramKernel::configure(const IImage *input, IDistribution1D *output)
+{
+    ARM_COMPUTE_ERROR_ON_TENSOR_NOT_2D(input);
+    ARM_COMPUTE_ERROR_ON_DATA_TYPE_CHANNEL_NOT_IN(input, 1, DataType::U8);
+    ARM_COMPUTE_ERROR_ON(nullptr == output);
+
+    _input  = input;
+    _output = output;
+
+    // Set appropriate function
+    _func = &NEHistogramKernel::histogram_fixed_U8;
+
+    constexpr unsigned int num_elems_processed_per_iteration = 1;
+
+    Window win = calculate_max_window(*input->info(), Steps(num_elems_processed_per_iteration));
+
+    INEKernel::configure(win);
+}
+
+void NEHistogramKernel::run(const Window &window)
+{
+    ARM_COMPUTE_ERROR_ON_UNCONFIGURED_KERNEL(this);
+    ARM_COMPUTE_ERROR_ON_INVALID_SUBWINDOW(INEKernel::window(), window);
+    ARM_COMPUTE_ERROR_ON(_func == nullptr);
+
+    (this->*_func)(window);
+}