COMPMID-439: Implement NEON Dequantization Layer.

Change-Id: I2f4f9d0d3437e9d8142f0f82b330233d31ffd552
Reviewed-on: http://mpd-gerrit.cambridge.arm.com/80086
Tested-by: Kaizen <jeremy.johnson+kaizengerrit@arm.com>
Reviewed-by: Anthony Barbier <anthony.barbier@arm.com>

1 files changed, 103 insertions, 0 deletions

diff --git a/src/core/NEON/kernels/NEDequantizationLayerKernel.cpp b/src/core/NEON/kernels/NEDequantizationLayerKernel.cpp
new file mode 100644
index 0000000000..70685c92c5
--- /dev/null
+++ b/src/core/NEON/kernels/NEDequantizationLayerKernel.cpp
@@ -0,0 +1,103 @@
+/*
+ * Copyright (c) 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/NEDequantizationLayerKernel.h"
+
+#include "arm_compute/core/Error.h"
+#include "arm_compute/core/Helpers.h"
+#include "arm_compute/core/TensorInfo.h"
+#include "arm_compute/core/Utils.h"
+#include "arm_compute/core/Validate.h"
+#include "arm_compute/core/Window.h"
+
+#include <arm_neon.h>
+
+using namespace arm_compute;
+
+NEDequantizationLayerKernel::NEDequantizationLayerKernel()
+    : _input(nullptr), _output(nullptr), _min(nullptr), _max(nullptr)
+{
+}
+
+void NEDequantizationLayerKernel::configure(const ITensor *input, ITensor *output, const float *min, const float *max)
+{
+    ARM_COMPUTE_ERROR_ON_DATA_TYPE_CHANNEL_NOT_IN(input, 1, DataType::U8);
+    ARM_COMPUTE_ERROR_ON_NULLPTR(output);
+    ARM_COMPUTE_ERROR_ON_NULLPTR(min);
+    ARM_COMPUTE_ERROR_ON_NULLPTR(max);
+
+    // Output tensor auto initialization if not yet initialized
+    auto_init_if_empty(*output->info(), input->info()->tensor_shape(), 1, DataType::F32, 0);
+
+    ARM_COMPUTE_ERROR_ON_DATA_TYPE_CHANNEL_NOT_IN(output, 1, DataType::F32);
+    ARM_COMPUTE_ERROR_ON_MISMATCHING_SHAPES(input, output);
+
+    _input  = input;
+    _output = output;
+    _min    = min;
+    _max    = max;
+
+    constexpr unsigned int num_elems_processed_per_iteration = 8;
+
+    // Configure window
+    Window                 win = calculate_max_window(*input->info(), Steps(num_elems_processed_per_iteration));
+    AccessWindowHorizontal output_access(output->info(), 0, num_elems_processed_per_iteration);
+    update_window_and_padding(win, AccessWindowHorizontal(input->info(), 0, num_elems_processed_per_iteration), output_access);
+    output_access.set_valid_region(win, input->info()->valid_region());
+
+    INEKernel::configure(win);
+}
+
+void NEDequantizationLayerKernel::run(const Window &window)
+{
+    ARM_COMPUTE_ERROR_ON_UNCONFIGURED_KERNEL(this);
+    ARM_COMPUTE_ERROR_ON_INVALID_SUBWINDOW(INEKernel::window(), window);
+
+    Iterator input(_input, window);
+    Iterator output(_output, window);
+
+    const float32x4_t vmin    = vdupq_n_f32(*_min);
+    const float       range   = *_max - *_min;
+    const float32x4_t scaling = vdupq_n_f32(range / 255.0f);
+
+    // Uniformly map values to range 8bit integers, i.e. [min, max] -> [0, 255]
+    execute_window_loop(window, [&](const Coordinates & id)
+    {
+        const uint8x8_t  val_u8       = vld1_u8(reinterpret_cast<uint8_t *>(input.ptr()));
+        const uint16x8_t val_u16      = vmovl_u8(val_u8);
+        const uint32x4_t val_u32_low  = vmovl_u16(vget_low_u16(val_u16));
+        const uint32x4_t val_u32_high = vmovl_u16(vget_high_u16(val_u16));
+        float32x4_t      val_low      = vcvtq_f32_u32(val_u32_low);
+        float32x4_t      val_high     = vcvtq_f32_u32(val_u32_high);
+
+        // Dequantize -> (q / 255.0 * range) + min
+        val_low  = vmulq_f32(val_low, scaling);
+        val_high = vmulq_f32(val_high, scaling);
+        val_low  = vaddq_f32(val_low, vmin);
+        val_high = vaddq_f32(val_high, vmin);
+
+        const float32x4x2_t dequantized = vuzpq_f32(val_low, val_high);
+        vst2q_f32(reinterpret_cast<float *>(output.ptr()), dequantized);
+    },
+    input, output);
+}