text: /* ----------------------------------------------------------------------    
  * Copyright (C) 2010-2014 ARM Limited. All rights reserved.    
  *    
  * $Date:        19. March 2015 
  * $Revision: 	V.1.4.5  
  *    
  * Project: 	    CMSIS DSP Library    
  * Title:	    arm_cfft_radix4_init_f32.c    
  *    
  * Description:	Radix-4 Decimation in Frequency Floating-point CFFT & CIFFT Initialization function    
  *    
  * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
  *  
  * Redistribution and use in source and binary forms, with or without 
  * modification, are permitted provided that the following conditions
  * are met:
  *   - Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  *   - Redistributions in binary form must reproduce the above copyright
  *     notice, this list of conditions and the following disclaimer in
  *     the documentation and/or other materials provided with the 
  *     distribution.
  *   - Neither the name of ARM LIMITED nor the names of its contributors
  *     may be used to endorse or promote products derived from this
  *     software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 
  * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGE.    
  
   Modifications 2017  Mostafa Saleh       (Ported to RISC-V PULPino)
  * -------------------------------------------------------------------- */
  
  
  #include "riscv_math.h"
  #include "riscv_common_tables.h"
  
  /**    
   * @ingroup groupTransforms    
   */
  
  /**    
   * @addtogroup ComplexFFT    
   * @{    
   */
  
  /**    
  * @brief  Initialization function for the floating-point CFFT/CIFFT.   
  * @deprecated Do not use this function.  It has been superceded by \ref riscv_cfft_f32 and will be removed
  * in the future.
  * @param[in,out] *S             points to an instance of the floating-point CFFT/CIFFT structure.   
  * @param[in]     fftLen         length of the FFT.   
  * @param[in]     ifftFlag       flag that selects forward (ifftFlag=0) or inverse (ifftFlag=1) transform.   
  * @param[in]     bitReverseFlag flag that enables (bitReverseFlag=1) or disables (bitReverseFlag=0) bit reversal of output.   
  * @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.   
  *    
  * \par Description:   
  * \par    
  * The parameter <code>ifftFlag</code> controls whether a forward or inverse transform is computed.    
  * Set(=1) ifftFlag for calculation of CIFFT otherwise  CFFT is calculated   
  * \par    
  * The parameter <code>bitReverseFlag</code> controls whether output is in normal order or bit reversed order.    
  * Set(=1) bitReverseFlag for output to be in normal order otherwise output is in bit reversed order.    
  * \par    
  * The parameter <code>fftLen</code>	Specifies length of CFFT/CIFFT process. Supported FFT Lengths are 16, 64, 256, 1024.    
  * \par    
  * This Function also initializes Twiddle factor table pointer and Bit reversal table pointer.    
  */
  
  riscv_status riscv_cfft_radix4_init_f32(
    riscv_cfft_radix4_instance_f32 * S,
    uint16_t fftLen,
    uint8_t ifftFlag,
    uint8_t bitReverseFlag)
  {
    /*  Initialise the default riscv status */
    riscv_status status = RISCV_MATH_SUCCESS;
  
    /*  Initialise the FFT length */
    S->fftLen = fftLen;
  
    /*  Initialise the Twiddle coefficient pointer */
    S->pTwiddle = (float32_t *) twiddleCoef;
  
    /*  Initialise the Flag for selection of CFFT or CIFFT */
    S->ifftFlag = ifftFlag;
  
    /*  Initialise the Flag for calculation Bit reversal or not */
    S->bitReverseFlag = bitReverseFlag;
  
    /*  Initializations of structure parameters depending on the FFT length */
    switch (S->fftLen)
    {
  
    case 4096u:
      /*  Initializations of structure parameters for 4096 point FFT */
  
      /*  Initialise the twiddle coef modifier value */
      S->twidCoefModifier = 1u;
      /*  Initialise the bit reversal table modifier */
      S->bitRevFactor = 1u;
      /*  Initialise the bit reversal table pointer */
      S->pBitRevTable = (uint16_t *) riscvBitRevTable;
      /*  Initialise the 1/fftLen Value */
      S->onebyfftLen = 0.000244140625;
      break;
  
    case 1024u:
      /*  Initializations of structure parameters for 1024 point FFT */
  
      /*  Initialise the twiddle coef modifier value */
      S->twidCoefModifier = 4u;
      /*  Initialise the bit reversal table modifier */
      S->bitRevFactor = 4u;
      /*  Initialise the bit reversal table pointer */
      S->pBitRevTable = (uint16_t *) & riscvBitRevTable[3];
      /*  Initialise the 1/fftLen Value */
      S->onebyfftLen = 0.0009765625f;
      break;
  
  
    case 256u:
      /*  Initializations of structure parameters for 256 point FFT */
      S->twidCoefModifier = 16u;
      S->bitRevFactor = 16u;
      S->pBitRevTable = (uint16_t *) & riscvBitRevTable[15];
      S->onebyfftLen = 0.00390625f;
      break;
  
    case 64u:
      /*  Initializations of structure parameters for 64 point FFT */
      S->twidCoefModifier = 64u;
      S->bitRevFactor = 64u;
      S->pBitRevTable = (uint16_t *) & riscvBitRevTable[63];
      S->onebyfftLen = 0.015625f;
      break;
  
    case 16u:
      /*  Initializations of structure parameters for 16 point FFT */
      S->twidCoefModifier = 256u;
      S->bitRevFactor = 256u;
      S->pBitRevTable = (uint16_t *) & riscvBitRevTable[255];
      S->onebyfftLen = 0.0625f;
      break;
  
  
    default:
      /*  Reporting argument error if fftSize is not valid value */
      status = RISCV_MATH_ARGUMENT_ERROR;
      break;
    }
  
    return (status);
  }
  
  /**    
   * @} end of ComplexFFT group    
   */
  