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			243 lines
		
	
	
		
			8.1 KiB
		
	
	
	
		
			C
		
	
	
		
			Executable File
		
	
	
	
	
			
		
		
	
	
			243 lines
		
	
	
		
			8.1 KiB
		
	
	
	
		
			C
		
	
	
		
			Executable File
		
	
	
	
	
| /* ----------------------------------------------------------------------    
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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_bitreversal.c    
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| *    
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| * Description:	This file has common tables like Bitreverse, reciprocal etc which are used across different functions    
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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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| 
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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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| /*    
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| * @brief  In-place bit reversal function.   
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| * @param[in, out] *pSrc        points to the in-place buffer of floating-point data type.   
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| * @param[in]      fftSize      length of the FFT.   
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| * @param[in]      bitRevFactor bit reversal modifier that supports different size FFTs with the same bit reversal table.   
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| * @param[in]      *pBitRevTab  points to the bit reversal table.   
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| * @return none.   
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| */
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| 
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| void arm_bitreversal_f32(
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| float32_t * pSrc,
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| uint16_t fftSize,
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| uint16_t bitRevFactor,
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| uint16_t * pBitRevTab)
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| {
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|    uint16_t fftLenBy2, fftLenBy2p1;
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|    uint16_t i, j;
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|    float32_t in;
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| 
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|    /*  Initializations */
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|    j = 0u;
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|    fftLenBy2 = fftSize >> 1u;
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|    fftLenBy2p1 = (fftSize >> 1u) + 1u;
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| 
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|    /* Bit Reversal Implementation */
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|    for (i = 0u; i <= (fftLenBy2 - 2u); i += 2u)
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|    {
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|       if(i < j)
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|       {
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|          /*  pSrc[i] <-> pSrc[j]; */
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|          in = pSrc[2u * i];
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|          pSrc[2u * i] = pSrc[2u * j];
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|          pSrc[2u * j] = in;
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| 
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|          /*  pSrc[i+1u] <-> pSrc[j+1u] */
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|          in = pSrc[(2u * i) + 1u];
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|          pSrc[(2u * i) + 1u] = pSrc[(2u * j) + 1u];
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|          pSrc[(2u * j) + 1u] = in;
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| 
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|          /*  pSrc[i+fftLenBy2p1] <-> pSrc[j+fftLenBy2p1] */
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|          in = pSrc[2u * (i + fftLenBy2p1)];
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|          pSrc[2u * (i + fftLenBy2p1)] = pSrc[2u * (j + fftLenBy2p1)];
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|          pSrc[2u * (j + fftLenBy2p1)] = in;
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| 
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|          /*  pSrc[i+fftLenBy2p1+1u] <-> pSrc[j+fftLenBy2p1+1u] */
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|          in = pSrc[(2u * (i + fftLenBy2p1)) + 1u];
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|          pSrc[(2u * (i + fftLenBy2p1)) + 1u] =
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|          pSrc[(2u * (j + fftLenBy2p1)) + 1u];
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|          pSrc[(2u * (j + fftLenBy2p1)) + 1u] = in;
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| 
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|       }
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| 
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|       /*  pSrc[i+1u] <-> pSrc[j+1u] */
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|       in = pSrc[2u * (i + 1u)];
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|       pSrc[2u * (i + 1u)] = pSrc[2u * (j + fftLenBy2)];
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|       pSrc[2u * (j + fftLenBy2)] = in;
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| 
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|       /*  pSrc[i+2u] <-> pSrc[j+2u] */
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|       in = pSrc[(2u * (i + 1u)) + 1u];
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|       pSrc[(2u * (i + 1u)) + 1u] = pSrc[(2u * (j + fftLenBy2)) + 1u];
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|       pSrc[(2u * (j + fftLenBy2)) + 1u] = in;
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| 
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|       /*  Reading the index for the bit reversal */
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|       j = *pBitRevTab;
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| 
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|       /*  Updating the bit reversal index depending on the fft length  */
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|       pBitRevTab += bitRevFactor;
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|    }
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| }
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| 
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| 
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| 
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| /*    
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| * @brief  In-place bit reversal function.   
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| * @param[in, out] *pSrc        points to the in-place buffer of Q31 data type.   
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| * @param[in]      fftLen       length of the FFT.   
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| * @param[in]      bitRevFactor bit reversal modifier that supports different size FFTs with the same bit reversal table   
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| * @param[in]      *pBitRevTab  points to bit reversal table.   
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| * @return none.   
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| */
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| 
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| void arm_bitreversal_q31(
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| q31_t * pSrc,
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| uint32_t fftLen,
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| uint16_t bitRevFactor,
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| uint16_t * pBitRevTable)
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| {
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|    uint32_t fftLenBy2, fftLenBy2p1, i, j;
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|    q31_t in;
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| 
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|    /*  Initializations      */
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|    j = 0u;
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|    fftLenBy2 = fftLen / 2u;
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|    fftLenBy2p1 = (fftLen / 2u) + 1u;
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| 
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|    /* Bit Reversal Implementation */
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|    for (i = 0u; i <= (fftLenBy2 - 2u); i += 2u)
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|    {
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|       if(i < j)
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|       {
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|          /*  pSrc[i] <-> pSrc[j]; */
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|          in = pSrc[2u * i];
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|          pSrc[2u * i] = pSrc[2u * j];
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|          pSrc[2u * j] = in;
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| 
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|          /*  pSrc[i+1u] <-> pSrc[j+1u] */
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|          in = pSrc[(2u * i) + 1u];
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|          pSrc[(2u * i) + 1u] = pSrc[(2u * j) + 1u];
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|          pSrc[(2u * j) + 1u] = in;
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| 
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|          /*  pSrc[i+fftLenBy2p1] <-> pSrc[j+fftLenBy2p1] */
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|          in = pSrc[2u * (i + fftLenBy2p1)];
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|          pSrc[2u * (i + fftLenBy2p1)] = pSrc[2u * (j + fftLenBy2p1)];
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|          pSrc[2u * (j + fftLenBy2p1)] = in;
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| 
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|          /*  pSrc[i+fftLenBy2p1+1u] <-> pSrc[j+fftLenBy2p1+1u] */
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|          in = pSrc[(2u * (i + fftLenBy2p1)) + 1u];
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|          pSrc[(2u * (i + fftLenBy2p1)) + 1u] =
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|          pSrc[(2u * (j + fftLenBy2p1)) + 1u];
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|          pSrc[(2u * (j + fftLenBy2p1)) + 1u] = in;
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| 
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|       }
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| 
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|       /*  pSrc[i+1u] <-> pSrc[j+1u] */
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|       in = pSrc[2u * (i + 1u)];
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|       pSrc[2u * (i + 1u)] = pSrc[2u * (j + fftLenBy2)];
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|       pSrc[2u * (j + fftLenBy2)] = in;
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| 
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|       /*  pSrc[i+2u] <-> pSrc[j+2u] */
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|       in = pSrc[(2u * (i + 1u)) + 1u];
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|       pSrc[(2u * (i + 1u)) + 1u] = pSrc[(2u * (j + fftLenBy2)) + 1u];
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|       pSrc[(2u * (j + fftLenBy2)) + 1u] = in;
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| 
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|       /*  Reading the index for the bit reversal */
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|       j = *pBitRevTable;
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| 
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|       /*  Updating the bit reversal index depending on the fft length */
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|       pBitRevTable += bitRevFactor;
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|    }
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| }
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| 
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| 
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| 
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| /*    
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|    * @brief  In-place bit reversal function.   
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|    * @param[in, out] *pSrc        points to the in-place buffer of Q15 data type.   
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|    * @param[in]      fftLen       length of the FFT.   
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|    * @param[in]      bitRevFactor bit reversal modifier that supports different size FFTs with the same bit reversal table   
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|    * @param[in]      *pBitRevTab  points to bit reversal table.   
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|    * @return none.   
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| */
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| 
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| void arm_bitreversal_q15(
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| q15_t * pSrc16,
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| uint32_t fftLen,
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| uint16_t bitRevFactor,
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| uint16_t * pBitRevTab)
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| {
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|    q31_t *pSrc = (q31_t *) pSrc16;
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|    q31_t in;
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|    uint32_t fftLenBy2, fftLenBy2p1;
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|    uint32_t i, j;
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| 
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|    /*  Initializations */
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|    j = 0u;
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|    fftLenBy2 = fftLen / 2u;
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|    fftLenBy2p1 = (fftLen / 2u) + 1u;
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| 
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|    /* Bit Reversal Implementation */
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|    for (i = 0u; i <= (fftLenBy2 - 2u); i += 2u)
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|    {
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|       if(i < j)
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|       {
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|          /*  pSrc[i] <-> pSrc[j]; */
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|          /*  pSrc[i+1u] <-> pSrc[j+1u] */
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|          in = pSrc[i];
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|          pSrc[i] = pSrc[j];
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|          pSrc[j] = in;
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| 
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|          /*  pSrc[i + fftLenBy2p1] <-> pSrc[j + fftLenBy2p1];  */
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|          /*  pSrc[i + fftLenBy2p1+1u] <-> pSrc[j + fftLenBy2p1+1u] */
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|          in = pSrc[i + fftLenBy2p1];
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|          pSrc[i + fftLenBy2p1] = pSrc[j + fftLenBy2p1];
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|          pSrc[j + fftLenBy2p1] = in;
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|       }
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| 
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|       /*  pSrc[i+1u] <-> pSrc[j+fftLenBy2];         */
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|       /*  pSrc[i+2] <-> pSrc[j+fftLenBy2+1u]  */
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|       in = pSrc[i + 1u];
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|       pSrc[i + 1u] = pSrc[j + fftLenBy2];
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|       pSrc[j + fftLenBy2] = in;
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| 
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|       /*  Reading the index for the bit reversal */
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|       j = *pBitRevTab;
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| 
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|       /*  Updating the bit reversal index depending on the fft length  */
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|       pBitRevTab += bitRevFactor;
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|    }
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| }
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