text: /* ----------------------------------------------------------------------
   * Project:      CMSIS DSP Library
   * Title:        arm_cfft_init_f32.c
   * Description:  Split Radix Decimation in Frequency CFFT Floating point processing function
   *
   * $Date:        18. March 2019
   * $Revision:    V1.6.0
   *
   * Target Processor: Cortex-M cores
   * -------------------------------------------------------------------- */
  /*
   * Copyright (C) 2010-2019 ARM Limited or its affiliates. All rights reserved.
   *
   * SPDX-License-Identifier: Apache-2.0
   *
   * Licensed under the Apache License, Version 2.0 (the License); you may
   * not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   * www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an AS IS BASIS, WITHOUT
   * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  #include "arm_math.h"
  #include "arm_common_tables.h"
  
  /**
    @ingroup groupTransforms
   */
  
  /**
    @addtogroup RealFFT
    @{
   */
  
  
  /**
    @brief         Initialization function for the 32pt floating-point real FFT.
    @param[in,out] S  points to an arm_rfft_fast_instance_f32 structure
    @return        execution status
                     - \ref ARM_MATH_SUCCESS        : Operation successful
                     - \ref ARM_MATH_ARGUMENT_ERROR : an error is detected
   */
  
  arm_status arm_rfft_32_fast_init_f32( arm_rfft_fast_instance_f32 * S ) {
  
    arm_cfft_instance_f32 * Sint;
  
    if( !S ) return ARM_MATH_ARGUMENT_ERROR;
  
    Sint = &(S->Sint);
    Sint->fftLen = 16U;
    S->fftLenRFFT = 32U;
  
    Sint->bitRevLength = ARMBITREVINDEXTABLE_16_TABLE_LENGTH;
    Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable16;
    Sint->pTwiddle     = (float32_t *) twiddleCoef_16;
    S->pTwiddleRFFT    = (float32_t *) twiddleCoef_rfft_32;
  
    return ARM_MATH_SUCCESS;
  }
  
  /**
    @brief         Initialization function for the 64pt floating-point real FFT.
    @param[in,out] S  points to an arm_rfft_fast_instance_f32 structure
    @return        execution status
                     - \ref ARM_MATH_SUCCESS        : Operation successful
                     - \ref ARM_MATH_ARGUMENT_ERROR : an error is detected
   */
  
  arm_status arm_rfft_64_fast_init_f32( arm_rfft_fast_instance_f32 * S ) {
  
    arm_cfft_instance_f32 * Sint;
  
    if( !S ) return ARM_MATH_ARGUMENT_ERROR;
  
    Sint = &(S->Sint);
    Sint->fftLen = 32U;
    S->fftLenRFFT = 64U;
  
    Sint->bitRevLength = ARMBITREVINDEXTABLE_32_TABLE_LENGTH;
    Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable32;
    Sint->pTwiddle     = (float32_t *) twiddleCoef_32;
    S->pTwiddleRFFT    = (float32_t *) twiddleCoef_rfft_64;
  
    return ARM_MATH_SUCCESS;
  }
  
  /**
    @brief         Initialization function for the 128pt floating-point real FFT.
    @param[in,out] S  points to an arm_rfft_fast_instance_f32 structure
    @return        execution status
                     - \ref ARM_MATH_SUCCESS        : Operation successful
                     - \ref ARM_MATH_ARGUMENT_ERROR : an error is detected
   */
  
  arm_status arm_rfft_128_fast_init_f32( arm_rfft_fast_instance_f32 * S ) {
  
    arm_cfft_instance_f32 * Sint;
  
    if( !S ) return ARM_MATH_ARGUMENT_ERROR;
  
    Sint = &(S->Sint);
    Sint->fftLen = 64U;
    S->fftLenRFFT = 128U;
  
    Sint->bitRevLength = ARMBITREVINDEXTABLE_64_TABLE_LENGTH;
    Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable64;
    Sint->pTwiddle     = (float32_t *) twiddleCoef_64;
    S->pTwiddleRFFT    = (float32_t *) twiddleCoef_rfft_128;
  
    return ARM_MATH_SUCCESS;
  }
  
  /**
    @brief         Initialization function for the 256pt floating-point real FFT.
    @param[in,out] S  points to an arm_rfft_fast_instance_f32 structure
    @return        execution status
                     - \ref ARM_MATH_SUCCESS        : Operation successful
                     - \ref ARM_MATH_ARGUMENT_ERROR : an error is detected
  */
  
  arm_status arm_rfft_256_fast_init_f32( arm_rfft_fast_instance_f32 * S ) {
  
    arm_cfft_instance_f32 * Sint;
  
    if( !S ) return ARM_MATH_ARGUMENT_ERROR;
  
    Sint = &(S->Sint);
    Sint->fftLen = 128U;
    S->fftLenRFFT = 256U;
  
    Sint->bitRevLength = ARMBITREVINDEXTABLE_128_TABLE_LENGTH;
    Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable128;
    Sint->pTwiddle     = (float32_t *) twiddleCoef_128;
    S->pTwiddleRFFT    = (float32_t *) twiddleCoef_rfft_256;
  
    return ARM_MATH_SUCCESS;
  }
  
  /**
    @brief         Initialization function for the 512pt floating-point real FFT.
    @param[in,out] S  points to an arm_rfft_fast_instance_f32 structure
    @return        execution status
                     - \ref ARM_MATH_SUCCESS        : Operation successful
                     - \ref ARM_MATH_ARGUMENT_ERROR : an error is detected
   */
  
  arm_status arm_rfft_512_fast_init_f32( arm_rfft_fast_instance_f32 * S ) {
  
    arm_cfft_instance_f32 * Sint;
  
    if( !S ) return ARM_MATH_ARGUMENT_ERROR;
  
    Sint = &(S->Sint);
    Sint->fftLen = 256U;
    S->fftLenRFFT = 512U;
  
    Sint->bitRevLength = ARMBITREVINDEXTABLE_256_TABLE_LENGTH;
    Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable256;
    Sint->pTwiddle     = (float32_t *) twiddleCoef_256;
    S->pTwiddleRFFT    = (float32_t *) twiddleCoef_rfft_512;
  
    return ARM_MATH_SUCCESS;
  }
  
  /**
    @brief         Initialization function for the 1024pt floating-point real FFT.
    @param[in,out] S  points to an arm_rfft_fast_instance_f32 structure
    @return        execution status
                     - \ref ARM_MATH_SUCCESS        : Operation successful
                     - \ref ARM_MATH_ARGUMENT_ERROR : an error is detected
   */
  
  arm_status arm_rfft_1024_fast_init_f32( arm_rfft_fast_instance_f32 * S ) {
  
    arm_cfft_instance_f32 * Sint;
  
    if( !S ) return ARM_MATH_ARGUMENT_ERROR;
  
    Sint = &(S->Sint);
    Sint->fftLen = 512U;
    S->fftLenRFFT = 1024U;
  
    Sint->bitRevLength = ARMBITREVINDEXTABLE_512_TABLE_LENGTH;
    Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable512;
    Sint->pTwiddle     = (float32_t *) twiddleCoef_512;
    S->pTwiddleRFFT    = (float32_t *) twiddleCoef_rfft_1024;
  
    return ARM_MATH_SUCCESS;
  }
  
  /**
    @brief         Initialization function for the 2048pt floating-point real FFT.
    @param[in,out] S  points to an arm_rfft_fast_instance_f32 structure
    @return        execution status
                     - \ref ARM_MATH_SUCCESS        : Operation successful
                     - \ref ARM_MATH_ARGUMENT_ERROR : an error is detected
   */
  arm_status arm_rfft_2048_fast_init_f32( arm_rfft_fast_instance_f32 * S ) {
  
    arm_cfft_instance_f32 * Sint;
  
    if( !S ) return ARM_MATH_ARGUMENT_ERROR;
  
    Sint = &(S->Sint);
    Sint->fftLen = 1024U;
    S->fftLenRFFT = 2048U;
  
    Sint->bitRevLength = ARMBITREVINDEXTABLE_1024_TABLE_LENGTH;
    Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable1024;
    Sint->pTwiddle     = (float32_t *) twiddleCoef_1024;
    S->pTwiddleRFFT    = (float32_t *) twiddleCoef_rfft_2048;
  
    return ARM_MATH_SUCCESS;
  }
  
  /**
  * @brief         Initialization function for the 4096pt floating-point real FFT.
  * @param[in,out] S  points to an arm_rfft_fast_instance_f32 structure
    @return        execution status
                     - \ref ARM_MATH_SUCCESS        : Operation successful
                     - \ref ARM_MATH_ARGUMENT_ERROR : an error is detected
   */
  
  arm_status arm_rfft_4096_fast_init_f32( arm_rfft_fast_instance_f32 * S ) {
  
    arm_cfft_instance_f32 * Sint;
  
    if( !S ) return ARM_MATH_ARGUMENT_ERROR;
  
    Sint = &(S->Sint);
    Sint->fftLen = 2048U;
    S->fftLenRFFT = 4096U;
  
    Sint->bitRevLength = ARMBITREVINDEXTABLE_2048_TABLE_LENGTH;
    Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable2048;
    Sint->pTwiddle     = (float32_t *) twiddleCoef_2048;
    S->pTwiddleRFFT    = (float32_t *) twiddleCoef_rfft_4096;
  
    return ARM_MATH_SUCCESS;
  }
  #include <assert.h>
  /**
    @brief         Initialization function for the floating-point real FFT.
    @param[in,out] S       points to an arm_rfft_fast_instance_f32 structure
    @param[in]     fftLen  length of the Real Sequence
    @return        execution status
                     - \ref ARM_MATH_SUCCESS        : Operation successful
                     - \ref ARM_MATH_ARGUMENT_ERROR : <code>fftLen</code> is not a supported length
  
    @par           Description
                     The parameter <code>fftLen</code> specifies the length of RFFT/CIFFT process.
                     Supported FFT Lengths are 32, 64, 128, 256, 512, 1024, 2048, 4096.
    @par
                     This Function also initializes Twiddle factor table pointer and Bit reversal table pointer.
   */
  
  arm_status arm_rfft_fast_init_f32(
    arm_rfft_fast_instance_f32 * S,
    uint16_t fftLen)
  {
    typedef arm_status(*fft_init_ptr)( arm_rfft_fast_instance_f32 *);
    fft_init_ptr fptr = 0x0;
  
    switch (fftLen)
    {
  #if 1
    case 4096U:
      //fptr = arm_rfft_4096_fast_init_f32;
      assert(0);
      break;
    case 2048U:
  //    fptr = arm_rfft_2048_fast_init_f32;
        assert(0);
    break;
    case 1024U:
  //    fptr = arm_rfft_1024_fast_init_f32;
        assert(0);
    break;
    case 512U:
  //    fptr = arm_rfft_512_fast_init_f32;
      assert(0);
      break;
    case 256U:
  //    fptr = arm_rfft_256_fast_init_f32;
      assert(0);
      break;
    case 128U:
      fptr = arm_rfft_128_fast_init_f32;
      break;
  #endif
    case 64U:
      fptr = arm_rfft_64_fast_init_f32;
      break;
    case 32U:
      fptr = arm_rfft_32_fast_init_f32;
      break;
    default:
      return ARM_MATH_ARGUMENT_ERROR;
    }
  
    if( ! fptr ) return ARM_MATH_ARGUMENT_ERROR;
    return fptr( S );
  
  }
  
  /**
    @} end of RealFFT group
   */
  