86 lines
2.5 KiB
C++
86 lines
2.5 KiB
C++
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// Copyright 2019 The Chromium Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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#include <algorithm>
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#include <array>
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#include <cassert>
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#include <cstring>
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#include "third_party/pffft/src/pffft.h"
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namespace {
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#if defined(TRANSFORM_REAL)
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// Real FFT.
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constexpr pffft_transform_t kTransform = PFFFT_REAL;
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constexpr size_t kSizeOfOneSample = sizeof(float);
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#elif defined(TRANSFORM_COMPLEX)
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// Complex FFT.
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constexpr pffft_transform_t kTransform = PFFFT_COMPLEX;
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constexpr size_t kSizeOfOneSample = 2 * sizeof(float); // Real plus imaginary.
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#else
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#error FFT transform type not defined.
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#endif
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bool IsValidSize(size_t n) {
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if (n == 0) {
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return false;
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}
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// PFFFT only supports transforms for inputs of length N of the form
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// N = (2^a)*(3^b)*(5^c) where a >= 5, b >=0, c >= 0.
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constexpr std::array<int, 3> kFactors = {2, 3, 5};
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std::array<int, kFactors.size()> factorization{};
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for (size_t i = 0; i < kFactors.size(); ++i) {
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const int factor = kFactors[i];
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while (n % factor == 0) {
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n /= factor;
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factorization[i]++;
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}
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}
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return factorization[0] >= 5 && n == 1;
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}
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float* AllocatePffftBuffer(size_t number_of_bytes) {
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return static_cast<float*>(pffft_aligned_malloc(number_of_bytes));
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}
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} // namespace
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// Entry point for LibFuzzer.
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extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
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// Set the number of FFT points to use |data| as input vector.
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// The latter is truncated if the number of bytes is not an integer
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// multiple of the size of one sample (which is either a real or a complex
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// floating point number).
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const size_t fft_size = size / kSizeOfOneSample;
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if (!IsValidSize(fft_size)) {
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return 0;
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}
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const size_t number_of_bytes = fft_size * kSizeOfOneSample;
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assert(number_of_bytes <= size);
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// Allocate input and output buffers.
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float* in = AllocatePffftBuffer(number_of_bytes);
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float* out = AllocatePffftBuffer(number_of_bytes);
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// Copy input data.
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std::memcpy(in, reinterpret_cast<const float*>(data), number_of_bytes);
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// Setup FFT.
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PFFFT_Setup* pffft_setup = pffft_new_setup(fft_size, kTransform);
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// Call different PFFFT functions to maximize the coverage.
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pffft_transform(pffft_setup, in, out, nullptr, PFFFT_FORWARD);
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pffft_zconvolve_accumulate(pffft_setup, out, out, out, 1.f);
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pffft_transform_ordered(pffft_setup, in, out, nullptr, PFFFT_BACKWARD);
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// Release memory.
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pffft_aligned_free(in);
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pffft_aligned_free(out);
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pffft_destroy_setup(pffft_setup);
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return 0;
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}
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