/* ----------------------------------------------------------------------
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* Copyright (C) 2010-2014 ARM Limited. All rights reserved.
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*
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* $Date: 19. March 2015
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* $Revision: V.1.4.5
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*
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* Project: CMSIS DSP Library
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* Title: arm_cfft_radix4_init_f32.c
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*
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* Description: Radix-4 Decimation in Frequency Floating-point CFFT & CIFFT Initialization function
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*
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* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* - Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* - Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* - Neither the name of ARM LIMITED nor the names of its contributors
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* may be used to endorse or promote products derived from this
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* software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
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* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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* -------------------------------------------------------------------- */
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#include "arm_math.h"
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#include "arm_common_tables.h"
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/**
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* @ingroup groupTransforms
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*/
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/**
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* @addtogroup ComplexFFT
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* @{
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*/
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/**
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* @brief Initialization function for the floating-point CFFT/CIFFT.
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* @deprecated Do not use this function. It has been superseded by \ref arm_cfft_f32 and will be removed
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* in the future.
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* @param[in,out] *S points to an instance of the floating-point CFFT/CIFFT structure.
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* @param[in] fftLen length of the FFT.
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* @param[in] ifftFlag flag that selects forward (ifftFlag=0) or inverse (ifftFlag=1) transform.
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* @param[in] bitReverseFlag flag that enables (bitReverseFlag=1) or disables (bitReverseFlag=0) bit reversal of output.
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* @return The function returns ARM_MATH_SUCCESS if initialization is successful or ARM_MATH_ARGUMENT_ERROR if <code>fftLen</code> is not a supported value.
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*
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* \par Description:
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* \par
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* The parameter <code>ifftFlag</code> controls whether a forward or inverse transform is computed.
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* Set(=1) ifftFlag for calculation of CIFFT otherwise CFFT is calculated
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* \par
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* The parameter <code>bitReverseFlag</code> controls whether output is in normal order or bit reversed order.
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* Set(=1) bitReverseFlag for output to be in normal order otherwise output is in bit reversed order.
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* \par
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* The parameter <code>fftLen</code> Specifies length of CFFT/CIFFT process. Supported FFT Lengths are 16, 64, 256, 1024.
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* \par
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* This Function also initializes Twiddle factor table pointer and Bit reversal table pointer.
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*/
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arm_status arm_cfft_radix2_init_f32(
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arm_cfft_radix2_instance_f32 * S,
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uint16_t fftLen,
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uint8_t ifftFlag,
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uint8_t bitReverseFlag)
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{
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/* Initialise the default arm status */
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arm_status status = ARM_MATH_SUCCESS;
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/* Initialise the FFT length */
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S->fftLen = fftLen;
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/* Initialise the Twiddle coefficient pointer */
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S->pTwiddle = (float32_t *) twiddleCoef;
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/* Initialise the Flag for selection of CFFT or CIFFT */
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S->ifftFlag = ifftFlag;
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/* Initialise the Flag for calculation Bit reversal or not */
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S->bitReverseFlag = bitReverseFlag;
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/* Initializations of structure parameters depending on the FFT length */
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switch (S->fftLen)
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{
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case 4096u:
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/* Initializations of structure parameters for 4096 point FFT */
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/* Initialise the twiddle coef modifier value */
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S->twidCoefModifier = 1u;
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/* Initialise the bit reversal table modifier */
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S->bitRevFactor = 1u;
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/* Initialise the bit reversal table pointer */
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S->pBitRevTable = (uint16_t *) armBitRevTable;
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/* Initialise the 1/fftLen Value */
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S->onebyfftLen = 0.000244140625;
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break;
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case 2048u:
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/* Initializations of structure parameters for 2048 point FFT */
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/* Initialise the twiddle coef modifier value */
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S->twidCoefModifier = 2u;
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/* Initialise the bit reversal table modifier */
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S->bitRevFactor = 2u;
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/* Initialise the bit reversal table pointer */
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S->pBitRevTable = (uint16_t *) & armBitRevTable[1];
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/* Initialise the 1/fftLen Value */
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S->onebyfftLen = 0.00048828125;
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break;
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case 1024u:
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/* Initializations of structure parameters for 1024 point FFT */
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/* Initialise the twiddle coef modifier value */
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S->twidCoefModifier = 4u;
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/* Initialise the bit reversal table modifier */
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S->bitRevFactor = 4u;
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/* Initialise the bit reversal table pointer */
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S->pBitRevTable = (uint16_t *) & armBitRevTable[3];
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/* Initialise the 1/fftLen Value */
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S->onebyfftLen = 0.0009765625f;
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break;
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case 512u:
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/* Initializations of structure parameters for 512 point FFT */
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/* Initialise the twiddle coef modifier value */
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S->twidCoefModifier = 8u;
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/* Initialise the bit reversal table modifier */
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S->bitRevFactor = 8u;
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/* Initialise the bit reversal table pointer */
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S->pBitRevTable = (uint16_t *) & armBitRevTable[7];
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/* Initialise the 1/fftLen Value */
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S->onebyfftLen = 0.001953125;
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break;
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case 256u:
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/* Initializations of structure parameters for 256 point FFT */
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S->twidCoefModifier = 16u;
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S->bitRevFactor = 16u;
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S->pBitRevTable = (uint16_t *) & armBitRevTable[15];
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S->onebyfftLen = 0.00390625f;
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break;
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case 128u:
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/* Initializations of structure parameters for 128 point FFT */
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S->twidCoefModifier = 32u;
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S->bitRevFactor = 32u;
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S->pBitRevTable = (uint16_t *) & armBitRevTable[31];
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S->onebyfftLen = 0.0078125;
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break;
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case 64u:
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/* Initializations of structure parameters for 64 point FFT */
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S->twidCoefModifier = 64u;
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S->bitRevFactor = 64u;
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S->pBitRevTable = (uint16_t *) & armBitRevTable[63];
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S->onebyfftLen = 0.015625f;
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break;
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case 32u:
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/* Initializations of structure parameters for 64 point FFT */
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S->twidCoefModifier = 128u;
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S->bitRevFactor = 128u;
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S->pBitRevTable = (uint16_t *) & armBitRevTable[127];
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S->onebyfftLen = 0.03125;
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break;
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case 16u:
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/* Initializations of structure parameters for 16 point FFT */
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S->twidCoefModifier = 256u;
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S->bitRevFactor = 256u;
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S->pBitRevTable = (uint16_t *) & armBitRevTable[255];
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S->onebyfftLen = 0.0625f;
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break;
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default:
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/* Reporting argument error if fftSize is not valid value */
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status = ARM_MATH_ARGUMENT_ERROR;
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break;
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}
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return (status);
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}
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/**
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* @} end of ComplexFFT group
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*/
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