COMPMID-1958: Implements 1D FFT in OpenCL.

Forward complex FFT implementation.

Change-Id: Ia0ba8740072e5adb06f8ead462a47abc8b5dd125
Signed-off-by: Georgios Pinitas <georgios.pinitas@arm.com>
Reviewed-on: https://review.mlplatform.org/c/904
Reviewed-by: Gian Marco Iodice <gianmarco.iodice@arm.com>
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>

1 files changed, 119 insertions, 0 deletions

diff --git a/src/runtime/CL/functions/CLFFT1D.cpp b/src/runtime/CL/functions/CLFFT1D.cpp
new file mode 100644
index 0000000000..6b6735ae58
--- /dev/null
+++ b/src/runtime/CL/functions/CLFFT1D.cpp
@@ -0,0 +1,119 @@
+/*
+ * 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/CL/functions/CLFFT1D.h"
+
+#include "arm_compute/core/CL/ICLTensor.h"
+#include "arm_compute/core/Validate.h"
+#include "arm_compute/core/utils/helpers/fft.h"
+#include "arm_compute/runtime/CL/CLScheduler.h"
+
+namespace arm_compute
+{
+CLFFT1D::CLFFT1D(std::shared_ptr<IMemoryManager> memory_manager)
+    : _memory_group(std::move(memory_manager)), _digit_reversed_input(), _digit_reverse_indices(), _digit_reverse_kernel(), _fft_kernels(), _num_ffts(0)
+{
+}
+
+void CLFFT1D::configure(const ICLTensor *input, ICLTensor *output, const FFT1DInfo &config)
+{
+    ARM_COMPUTE_ERROR_ON_NULLPTR(input, output);
+    ARM_COMPUTE_ERROR_THROW_ON(CLFFT1D::validate(input->info(), output->info(), config));
+
+    // Decompose size to radix factors
+    const auto         supported_radix   = CLFFTRadixStageKernel::supported_radix();
+    const unsigned int N                 = input->info()->tensor_shape()[config.axis];
+    const auto         decomposed_vector = arm_compute::helpers::fft::decompose_stages(N, supported_radix);
+    ARM_COMPUTE_ERROR_ON(decomposed_vector.empty());
+
+    // Configure digit reverse
+    TensorInfo digit_reverse_indices_info(TensorShape(input->info()->tensor_shape()[config.axis]), 1, DataType::U32);
+    _digit_reverse_indices.allocator()->init(digit_reverse_indices_info);
+    _memory_group.manage(&_digit_reversed_input);
+    _digit_reverse_kernel.configure(input, &_digit_reversed_input, &_digit_reverse_indices, config.axis);
+
+    // Create and configure FFT kernels
+    unsigned int Nx = 1;
+    _num_ffts       = decomposed_vector.size();
+    _fft_kernels    = arm_compute::support::cpp14::make_unique<CLFFTRadixStageKernel[]>(_num_ffts);
+    for(unsigned int i = 0; i < _num_ffts; ++i)
+    {
+        const unsigned int radix_for_stage = decomposed_vector.at(i);
+
+        FFTRadixStageKernelDescriptor fft_kernel_desc;
+        fft_kernel_desc.axis           = config.axis;
+        fft_kernel_desc.radix          = radix_for_stage;
+        fft_kernel_desc.Nx             = Nx;
+        fft_kernel_desc.is_first_stage = (i == 0);
+        _fft_kernels[i].configure(&_digit_reversed_input, i == (_num_ffts - 1) ? output : nullptr, fft_kernel_desc);
+
+        Nx *= radix_for_stage;
+    }
+
+    // Allocate tensors
+    _digit_reversed_input.allocator()->allocate();
+    _digit_reverse_indices.allocator()->allocate();
+
+    // Init digit reverse indices
+    const auto digit_reverse_cpu = arm_compute::helpers::fft::digit_reverse_indices(N, decomposed_vector);
+    _digit_reverse_indices.map(CLScheduler::get().queue(), true);
+    std::copy_n(digit_reverse_cpu.data(), N, reinterpret_cast<unsigned int *>(_digit_reverse_indices.buffer()));
+    _digit_reverse_indices.unmap(CLScheduler::get().queue());
+}
+
+Status CLFFT1D::validate(const ITensorInfo *input, const ITensorInfo *output, const FFT1DInfo &config)
+{
+    ARM_COMPUTE_RETURN_ERROR_ON_NULLPTR(input, output);
+    ARM_COMPUTE_RETURN_ERROR_ON_DATA_TYPE_CHANNEL_NOT_IN(input, 2, DataType::F32);
+    ARM_COMPUTE_RETURN_ERROR_ON(config.axis != 0);
+
+    // Check if FFT is decomposable
+    const auto         supported_radix   = CLFFTRadixStageKernel::supported_radix();
+    const unsigned int N                 = input->tensor_shape()[config.axis];
+    const auto         decomposed_vector = arm_compute::helpers::fft::decompose_stages(N, supported_radix);
+    ARM_COMPUTE_RETURN_ERROR_ON(decomposed_vector.empty());
+
+    // Checks performed when output is configured
+    if((output != nullptr) && (output->total_size() != 0))
+    {
+        ARM_COMPUTE_RETURN_ERROR_ON_MISMATCHING_SHAPES(input, output);
+        ARM_COMPUTE_RETURN_ERROR_ON_MISMATCHING_DATA_TYPES(input, output);
+    }
+
+    return Status{};
+}
+
+void CLFFT1D::run()
+{
+    _memory_group.acquire();
+
+    CLScheduler::get().enqueue(_digit_reverse_kernel, false);
+
+    for(unsigned int i = 0; i < _num_ffts; ++i)
+    {
+        CLScheduler::get().enqueue(_fft_kernels[i], i == (_num_ffts - 1));
+    }
+
+    _memory_group.release();
+}
+} // namespace arm_compute