V4.0.1 of the ARM CMSIS DSP libraries. Note that arm_bitreversal2.s, arm_cfft_f32.c and arm_rfft_fast_f32.c had to be removed. arm_bitreversal2.s will not assemble with the online tools. So, the fast f32 FFT functions are not yet available. All the other FFT functions are available.
Dependents: MPU9150_Example fir_f32 fir_f32 MPU9150_nucleo_noni2cdev ... more
TransformFunctions/arm_cfft_radix2_f32.c@0:3d9c67d97d6f, 2014-07-28 (annotated)
- Committer:
- emh203
- Date:
- Mon Jul 28 15:03:15 2014 +0000
- Revision:
- 0:3d9c67d97d6f
1st working commit. Had to remove arm_bitreversal2.s arm_cfft_f32.c and arm_rfft_fast_f32.c. The .s will not assemble. For now I removed these functions so we could at least have a library for the other functions.
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
emh203 | 0:3d9c67d97d6f | 1 | /* ---------------------------------------------------------------------- |
emh203 | 0:3d9c67d97d6f | 2 | * Copyright (C) 2010-2014 ARM Limited. All rights reserved. |
emh203 | 0:3d9c67d97d6f | 3 | * |
emh203 | 0:3d9c67d97d6f | 4 | * $Date: 12. March 2014 |
emh203 | 0:3d9c67d97d6f | 5 | * $Revision: V1.4.3 |
emh203 | 0:3d9c67d97d6f | 6 | * |
emh203 | 0:3d9c67d97d6f | 7 | * Project: CMSIS DSP Library |
emh203 | 0:3d9c67d97d6f | 8 | * Title: arm_cfft_radix2_f32.c |
emh203 | 0:3d9c67d97d6f | 9 | * |
emh203 | 0:3d9c67d97d6f | 10 | * Description: Radix-2 Decimation in Frequency CFFT & CIFFT Floating point processing function |
emh203 | 0:3d9c67d97d6f | 11 | * |
emh203 | 0:3d9c67d97d6f | 12 | * |
emh203 | 0:3d9c67d97d6f | 13 | * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0 |
emh203 | 0:3d9c67d97d6f | 14 | * |
emh203 | 0:3d9c67d97d6f | 15 | * Redistribution and use in source and binary forms, with or without |
emh203 | 0:3d9c67d97d6f | 16 | * modification, are permitted provided that the following conditions |
emh203 | 0:3d9c67d97d6f | 17 | * are met: |
emh203 | 0:3d9c67d97d6f | 18 | * - Redistributions of source code must retain the above copyright |
emh203 | 0:3d9c67d97d6f | 19 | * notice, this list of conditions and the following disclaimer. |
emh203 | 0:3d9c67d97d6f | 20 | * - Redistributions in binary form must reproduce the above copyright |
emh203 | 0:3d9c67d97d6f | 21 | * notice, this list of conditions and the following disclaimer in |
emh203 | 0:3d9c67d97d6f | 22 | * the documentation and/or other materials provided with the |
emh203 | 0:3d9c67d97d6f | 23 | * distribution. |
emh203 | 0:3d9c67d97d6f | 24 | * - Neither the name of ARM LIMITED nor the names of its contributors |
emh203 | 0:3d9c67d97d6f | 25 | * may be used to endorse or promote products derived from this |
emh203 | 0:3d9c67d97d6f | 26 | * software without specific prior written permission. |
emh203 | 0:3d9c67d97d6f | 27 | * |
emh203 | 0:3d9c67d97d6f | 28 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
emh203 | 0:3d9c67d97d6f | 29 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
emh203 | 0:3d9c67d97d6f | 30 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
emh203 | 0:3d9c67d97d6f | 31 | * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
emh203 | 0:3d9c67d97d6f | 32 | * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
emh203 | 0:3d9c67d97d6f | 33 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
emh203 | 0:3d9c67d97d6f | 34 | * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
emh203 | 0:3d9c67d97d6f | 35 | * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER |
emh203 | 0:3d9c67d97d6f | 36 | * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
emh203 | 0:3d9c67d97d6f | 37 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN |
emh203 | 0:3d9c67d97d6f | 38 | * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
emh203 | 0:3d9c67d97d6f | 39 | * POSSIBILITY OF SUCH DAMAGE. |
emh203 | 0:3d9c67d97d6f | 40 | * -------------------------------------------------------------------- */ |
emh203 | 0:3d9c67d97d6f | 41 | |
emh203 | 0:3d9c67d97d6f | 42 | #include "arm_math.h" |
emh203 | 0:3d9c67d97d6f | 43 | |
emh203 | 0:3d9c67d97d6f | 44 | void arm_radix2_butterfly_f32( |
emh203 | 0:3d9c67d97d6f | 45 | float32_t * pSrc, |
emh203 | 0:3d9c67d97d6f | 46 | uint32_t fftLen, |
emh203 | 0:3d9c67d97d6f | 47 | float32_t * pCoef, |
emh203 | 0:3d9c67d97d6f | 48 | uint16_t twidCoefModifier); |
emh203 | 0:3d9c67d97d6f | 49 | |
emh203 | 0:3d9c67d97d6f | 50 | void arm_radix2_butterfly_inverse_f32( |
emh203 | 0:3d9c67d97d6f | 51 | float32_t * pSrc, |
emh203 | 0:3d9c67d97d6f | 52 | uint32_t fftLen, |
emh203 | 0:3d9c67d97d6f | 53 | float32_t * pCoef, |
emh203 | 0:3d9c67d97d6f | 54 | uint16_t twidCoefModifier, |
emh203 | 0:3d9c67d97d6f | 55 | float32_t onebyfftLen); |
emh203 | 0:3d9c67d97d6f | 56 | |
emh203 | 0:3d9c67d97d6f | 57 | extern void arm_bitreversal_f32( |
emh203 | 0:3d9c67d97d6f | 58 | float32_t * pSrc, |
emh203 | 0:3d9c67d97d6f | 59 | uint16_t fftSize, |
emh203 | 0:3d9c67d97d6f | 60 | uint16_t bitRevFactor, |
emh203 | 0:3d9c67d97d6f | 61 | uint16_t * pBitRevTab); |
emh203 | 0:3d9c67d97d6f | 62 | |
emh203 | 0:3d9c67d97d6f | 63 | /** |
emh203 | 0:3d9c67d97d6f | 64 | * @ingroup groupTransforms |
emh203 | 0:3d9c67d97d6f | 65 | */ |
emh203 | 0:3d9c67d97d6f | 66 | |
emh203 | 0:3d9c67d97d6f | 67 | /** |
emh203 | 0:3d9c67d97d6f | 68 | * @addtogroup ComplexFFT |
emh203 | 0:3d9c67d97d6f | 69 | * @{ |
emh203 | 0:3d9c67d97d6f | 70 | */ |
emh203 | 0:3d9c67d97d6f | 71 | |
emh203 | 0:3d9c67d97d6f | 72 | /** |
emh203 | 0:3d9c67d97d6f | 73 | * @details |
emh203 | 0:3d9c67d97d6f | 74 | * @brief Radix-2 CFFT/CIFFT. |
emh203 | 0:3d9c67d97d6f | 75 | * @deprecated Do not use this function. It has been superceded by \ref arm_cfft_f32 and will be removed |
emh203 | 0:3d9c67d97d6f | 76 | * in the future. |
emh203 | 0:3d9c67d97d6f | 77 | * @param[in] *S points to an instance of the floating-point Radix-2 CFFT/CIFFT structure. |
emh203 | 0:3d9c67d97d6f | 78 | * @param[in, out] *pSrc points to the complex data buffer of size <code>2*fftLen</code>. Processing occurs in-place. |
emh203 | 0:3d9c67d97d6f | 79 | * @return none. |
emh203 | 0:3d9c67d97d6f | 80 | */ |
emh203 | 0:3d9c67d97d6f | 81 | |
emh203 | 0:3d9c67d97d6f | 82 | void arm_cfft_radix2_f32( |
emh203 | 0:3d9c67d97d6f | 83 | const arm_cfft_radix2_instance_f32 * S, |
emh203 | 0:3d9c67d97d6f | 84 | float32_t * pSrc) |
emh203 | 0:3d9c67d97d6f | 85 | { |
emh203 | 0:3d9c67d97d6f | 86 | |
emh203 | 0:3d9c67d97d6f | 87 | if(S->ifftFlag == 1u) |
emh203 | 0:3d9c67d97d6f | 88 | { |
emh203 | 0:3d9c67d97d6f | 89 | /* Complex IFFT radix-2 */ |
emh203 | 0:3d9c67d97d6f | 90 | arm_radix2_butterfly_inverse_f32(pSrc, S->fftLen, S->pTwiddle, |
emh203 | 0:3d9c67d97d6f | 91 | S->twidCoefModifier, S->onebyfftLen); |
emh203 | 0:3d9c67d97d6f | 92 | } |
emh203 | 0:3d9c67d97d6f | 93 | else |
emh203 | 0:3d9c67d97d6f | 94 | { |
emh203 | 0:3d9c67d97d6f | 95 | /* Complex FFT radix-2 */ |
emh203 | 0:3d9c67d97d6f | 96 | arm_radix2_butterfly_f32(pSrc, S->fftLen, S->pTwiddle, |
emh203 | 0:3d9c67d97d6f | 97 | S->twidCoefModifier); |
emh203 | 0:3d9c67d97d6f | 98 | } |
emh203 | 0:3d9c67d97d6f | 99 | |
emh203 | 0:3d9c67d97d6f | 100 | if(S->bitReverseFlag == 1u) |
emh203 | 0:3d9c67d97d6f | 101 | { |
emh203 | 0:3d9c67d97d6f | 102 | /* Bit Reversal */ |
emh203 | 0:3d9c67d97d6f | 103 | arm_bitreversal_f32(pSrc, S->fftLen, S->bitRevFactor, S->pBitRevTable); |
emh203 | 0:3d9c67d97d6f | 104 | } |
emh203 | 0:3d9c67d97d6f | 105 | |
emh203 | 0:3d9c67d97d6f | 106 | } |
emh203 | 0:3d9c67d97d6f | 107 | |
emh203 | 0:3d9c67d97d6f | 108 | |
emh203 | 0:3d9c67d97d6f | 109 | /** |
emh203 | 0:3d9c67d97d6f | 110 | * @} end of ComplexFFT group |
emh203 | 0:3d9c67d97d6f | 111 | */ |
emh203 | 0:3d9c67d97d6f | 112 | |
emh203 | 0:3d9c67d97d6f | 113 | |
emh203 | 0:3d9c67d97d6f | 114 | |
emh203 | 0:3d9c67d97d6f | 115 | /* ---------------------------------------------------------------------- |
emh203 | 0:3d9c67d97d6f | 116 | ** Internal helper function used by the FFTs |
emh203 | 0:3d9c67d97d6f | 117 | ** ------------------------------------------------------------------- */ |
emh203 | 0:3d9c67d97d6f | 118 | |
emh203 | 0:3d9c67d97d6f | 119 | /* |
emh203 | 0:3d9c67d97d6f | 120 | * @brief Core function for the floating-point CFFT butterfly process. |
emh203 | 0:3d9c67d97d6f | 121 | * @param[in, out] *pSrc points to the in-place buffer of floating-point data type. |
emh203 | 0:3d9c67d97d6f | 122 | * @param[in] fftLen length of the FFT. |
emh203 | 0:3d9c67d97d6f | 123 | * @param[in] *pCoef points to the twiddle coefficient buffer. |
emh203 | 0:3d9c67d97d6f | 124 | * @param[in] twidCoefModifier twiddle coefficient modifier that supports different size FFTs with the same twiddle factor table. |
emh203 | 0:3d9c67d97d6f | 125 | * @return none. |
emh203 | 0:3d9c67d97d6f | 126 | */ |
emh203 | 0:3d9c67d97d6f | 127 | |
emh203 | 0:3d9c67d97d6f | 128 | void arm_radix2_butterfly_f32( |
emh203 | 0:3d9c67d97d6f | 129 | float32_t * pSrc, |
emh203 | 0:3d9c67d97d6f | 130 | uint32_t fftLen, |
emh203 | 0:3d9c67d97d6f | 131 | float32_t * pCoef, |
emh203 | 0:3d9c67d97d6f | 132 | uint16_t twidCoefModifier) |
emh203 | 0:3d9c67d97d6f | 133 | { |
emh203 | 0:3d9c67d97d6f | 134 | |
emh203 | 0:3d9c67d97d6f | 135 | uint32_t i, j, k, l; |
emh203 | 0:3d9c67d97d6f | 136 | uint32_t n1, n2, ia; |
emh203 | 0:3d9c67d97d6f | 137 | float32_t xt, yt, cosVal, sinVal; |
emh203 | 0:3d9c67d97d6f | 138 | float32_t p0, p1, p2, p3; |
emh203 | 0:3d9c67d97d6f | 139 | float32_t a0, a1; |
emh203 | 0:3d9c67d97d6f | 140 | |
emh203 | 0:3d9c67d97d6f | 141 | #ifndef ARM_MATH_CM0_FAMILY |
emh203 | 0:3d9c67d97d6f | 142 | |
emh203 | 0:3d9c67d97d6f | 143 | /* Initializations for the first stage */ |
emh203 | 0:3d9c67d97d6f | 144 | n2 = fftLen >> 1; |
emh203 | 0:3d9c67d97d6f | 145 | ia = 0; |
emh203 | 0:3d9c67d97d6f | 146 | i = 0; |
emh203 | 0:3d9c67d97d6f | 147 | |
emh203 | 0:3d9c67d97d6f | 148 | // loop for groups |
emh203 | 0:3d9c67d97d6f | 149 | for (k = n2; k > 0; k--) |
emh203 | 0:3d9c67d97d6f | 150 | { |
emh203 | 0:3d9c67d97d6f | 151 | cosVal = pCoef[ia * 2]; |
emh203 | 0:3d9c67d97d6f | 152 | sinVal = pCoef[(ia * 2) + 1]; |
emh203 | 0:3d9c67d97d6f | 153 | |
emh203 | 0:3d9c67d97d6f | 154 | /* Twiddle coefficients index modifier */ |
emh203 | 0:3d9c67d97d6f | 155 | ia += twidCoefModifier; |
emh203 | 0:3d9c67d97d6f | 156 | |
emh203 | 0:3d9c67d97d6f | 157 | /* index calculation for the input as, */ |
emh203 | 0:3d9c67d97d6f | 158 | /* pSrc[i + 0], pSrc[i + fftLen/1] */ |
emh203 | 0:3d9c67d97d6f | 159 | l = i + n2; |
emh203 | 0:3d9c67d97d6f | 160 | |
emh203 | 0:3d9c67d97d6f | 161 | /* Butterfly implementation */ |
emh203 | 0:3d9c67d97d6f | 162 | a0 = pSrc[2 * i] + pSrc[2 * l]; |
emh203 | 0:3d9c67d97d6f | 163 | xt = pSrc[2 * i] - pSrc[2 * l]; |
emh203 | 0:3d9c67d97d6f | 164 | |
emh203 | 0:3d9c67d97d6f | 165 | yt = pSrc[2 * i + 1] - pSrc[2 * l + 1]; |
emh203 | 0:3d9c67d97d6f | 166 | a1 = pSrc[2 * l + 1] + pSrc[2 * i + 1]; |
emh203 | 0:3d9c67d97d6f | 167 | |
emh203 | 0:3d9c67d97d6f | 168 | p0 = xt * cosVal; |
emh203 | 0:3d9c67d97d6f | 169 | p1 = yt * sinVal; |
emh203 | 0:3d9c67d97d6f | 170 | p2 = yt * cosVal; |
emh203 | 0:3d9c67d97d6f | 171 | p3 = xt * sinVal; |
emh203 | 0:3d9c67d97d6f | 172 | |
emh203 | 0:3d9c67d97d6f | 173 | pSrc[2 * i] = a0; |
emh203 | 0:3d9c67d97d6f | 174 | pSrc[2 * i + 1] = a1; |
emh203 | 0:3d9c67d97d6f | 175 | |
emh203 | 0:3d9c67d97d6f | 176 | pSrc[2 * l] = p0 + p1; |
emh203 | 0:3d9c67d97d6f | 177 | pSrc[2 * l + 1] = p2 - p3; |
emh203 | 0:3d9c67d97d6f | 178 | |
emh203 | 0:3d9c67d97d6f | 179 | i++; |
emh203 | 0:3d9c67d97d6f | 180 | } // groups loop end |
emh203 | 0:3d9c67d97d6f | 181 | |
emh203 | 0:3d9c67d97d6f | 182 | twidCoefModifier <<= 1u; |
emh203 | 0:3d9c67d97d6f | 183 | |
emh203 | 0:3d9c67d97d6f | 184 | // loop for stage |
emh203 | 0:3d9c67d97d6f | 185 | for (k = n2; k > 2; k = k >> 1) |
emh203 | 0:3d9c67d97d6f | 186 | { |
emh203 | 0:3d9c67d97d6f | 187 | n1 = n2; |
emh203 | 0:3d9c67d97d6f | 188 | n2 = n2 >> 1; |
emh203 | 0:3d9c67d97d6f | 189 | ia = 0; |
emh203 | 0:3d9c67d97d6f | 190 | |
emh203 | 0:3d9c67d97d6f | 191 | // loop for groups |
emh203 | 0:3d9c67d97d6f | 192 | j = 0; |
emh203 | 0:3d9c67d97d6f | 193 | do |
emh203 | 0:3d9c67d97d6f | 194 | { |
emh203 | 0:3d9c67d97d6f | 195 | cosVal = pCoef[ia * 2]; |
emh203 | 0:3d9c67d97d6f | 196 | sinVal = pCoef[(ia * 2) + 1]; |
emh203 | 0:3d9c67d97d6f | 197 | ia += twidCoefModifier; |
emh203 | 0:3d9c67d97d6f | 198 | |
emh203 | 0:3d9c67d97d6f | 199 | // loop for butterfly |
emh203 | 0:3d9c67d97d6f | 200 | i = j; |
emh203 | 0:3d9c67d97d6f | 201 | do |
emh203 | 0:3d9c67d97d6f | 202 | { |
emh203 | 0:3d9c67d97d6f | 203 | l = i + n2; |
emh203 | 0:3d9c67d97d6f | 204 | a0 = pSrc[2 * i] + pSrc[2 * l]; |
emh203 | 0:3d9c67d97d6f | 205 | xt = pSrc[2 * i] - pSrc[2 * l]; |
emh203 | 0:3d9c67d97d6f | 206 | |
emh203 | 0:3d9c67d97d6f | 207 | yt = pSrc[2 * i + 1] - pSrc[2 * l + 1]; |
emh203 | 0:3d9c67d97d6f | 208 | a1 = pSrc[2 * l + 1] + pSrc[2 * i + 1]; |
emh203 | 0:3d9c67d97d6f | 209 | |
emh203 | 0:3d9c67d97d6f | 210 | p0 = xt * cosVal; |
emh203 | 0:3d9c67d97d6f | 211 | p1 = yt * sinVal; |
emh203 | 0:3d9c67d97d6f | 212 | p2 = yt * cosVal; |
emh203 | 0:3d9c67d97d6f | 213 | p3 = xt * sinVal; |
emh203 | 0:3d9c67d97d6f | 214 | |
emh203 | 0:3d9c67d97d6f | 215 | pSrc[2 * i] = a0; |
emh203 | 0:3d9c67d97d6f | 216 | pSrc[2 * i + 1] = a1; |
emh203 | 0:3d9c67d97d6f | 217 | |
emh203 | 0:3d9c67d97d6f | 218 | pSrc[2 * l] = p0 + p1; |
emh203 | 0:3d9c67d97d6f | 219 | pSrc[2 * l + 1] = p2 - p3; |
emh203 | 0:3d9c67d97d6f | 220 | |
emh203 | 0:3d9c67d97d6f | 221 | i += n1; |
emh203 | 0:3d9c67d97d6f | 222 | } while( i < fftLen ); // butterfly loop end |
emh203 | 0:3d9c67d97d6f | 223 | j++; |
emh203 | 0:3d9c67d97d6f | 224 | } while( j < n2); // groups loop end |
emh203 | 0:3d9c67d97d6f | 225 | twidCoefModifier <<= 1u; |
emh203 | 0:3d9c67d97d6f | 226 | } // stages loop end |
emh203 | 0:3d9c67d97d6f | 227 | |
emh203 | 0:3d9c67d97d6f | 228 | // loop for butterfly |
emh203 | 0:3d9c67d97d6f | 229 | for (i = 0; i < fftLen; i += 2) |
emh203 | 0:3d9c67d97d6f | 230 | { |
emh203 | 0:3d9c67d97d6f | 231 | a0 = pSrc[2 * i] + pSrc[2 * i + 2]; |
emh203 | 0:3d9c67d97d6f | 232 | xt = pSrc[2 * i] - pSrc[2 * i + 2]; |
emh203 | 0:3d9c67d97d6f | 233 | |
emh203 | 0:3d9c67d97d6f | 234 | yt = pSrc[2 * i + 1] - pSrc[2 * i + 3]; |
emh203 | 0:3d9c67d97d6f | 235 | a1 = pSrc[2 * i + 3] + pSrc[2 * i + 1]; |
emh203 | 0:3d9c67d97d6f | 236 | |
emh203 | 0:3d9c67d97d6f | 237 | pSrc[2 * i] = a0; |
emh203 | 0:3d9c67d97d6f | 238 | pSrc[2 * i + 1] = a1; |
emh203 | 0:3d9c67d97d6f | 239 | pSrc[2 * i + 2] = xt; |
emh203 | 0:3d9c67d97d6f | 240 | pSrc[2 * i + 3] = yt; |
emh203 | 0:3d9c67d97d6f | 241 | } // groups loop end |
emh203 | 0:3d9c67d97d6f | 242 | |
emh203 | 0:3d9c67d97d6f | 243 | #else |
emh203 | 0:3d9c67d97d6f | 244 | |
emh203 | 0:3d9c67d97d6f | 245 | n2 = fftLen; |
emh203 | 0:3d9c67d97d6f | 246 | |
emh203 | 0:3d9c67d97d6f | 247 | // loop for stage |
emh203 | 0:3d9c67d97d6f | 248 | for (k = fftLen; k > 1; k = k >> 1) |
emh203 | 0:3d9c67d97d6f | 249 | { |
emh203 | 0:3d9c67d97d6f | 250 | n1 = n2; |
emh203 | 0:3d9c67d97d6f | 251 | n2 = n2 >> 1; |
emh203 | 0:3d9c67d97d6f | 252 | ia = 0; |
emh203 | 0:3d9c67d97d6f | 253 | |
emh203 | 0:3d9c67d97d6f | 254 | // loop for groups |
emh203 | 0:3d9c67d97d6f | 255 | j = 0; |
emh203 | 0:3d9c67d97d6f | 256 | do |
emh203 | 0:3d9c67d97d6f | 257 | { |
emh203 | 0:3d9c67d97d6f | 258 | cosVal = pCoef[ia * 2]; |
emh203 | 0:3d9c67d97d6f | 259 | sinVal = pCoef[(ia * 2) + 1]; |
emh203 | 0:3d9c67d97d6f | 260 | ia += twidCoefModifier; |
emh203 | 0:3d9c67d97d6f | 261 | |
emh203 | 0:3d9c67d97d6f | 262 | // loop for butterfly |
emh203 | 0:3d9c67d97d6f | 263 | i = j; |
emh203 | 0:3d9c67d97d6f | 264 | do |
emh203 | 0:3d9c67d97d6f | 265 | { |
emh203 | 0:3d9c67d97d6f | 266 | l = i + n2; |
emh203 | 0:3d9c67d97d6f | 267 | a0 = pSrc[2 * i] + pSrc[2 * l]; |
emh203 | 0:3d9c67d97d6f | 268 | xt = pSrc[2 * i] - pSrc[2 * l]; |
emh203 | 0:3d9c67d97d6f | 269 | |
emh203 | 0:3d9c67d97d6f | 270 | yt = pSrc[2 * i + 1] - pSrc[2 * l + 1]; |
emh203 | 0:3d9c67d97d6f | 271 | a1 = pSrc[2 * l + 1] + pSrc[2 * i + 1]; |
emh203 | 0:3d9c67d97d6f | 272 | |
emh203 | 0:3d9c67d97d6f | 273 | p0 = xt * cosVal; |
emh203 | 0:3d9c67d97d6f | 274 | p1 = yt * sinVal; |
emh203 | 0:3d9c67d97d6f | 275 | p2 = yt * cosVal; |
emh203 | 0:3d9c67d97d6f | 276 | p3 = xt * sinVal; |
emh203 | 0:3d9c67d97d6f | 277 | |
emh203 | 0:3d9c67d97d6f | 278 | pSrc[2 * i] = a0; |
emh203 | 0:3d9c67d97d6f | 279 | pSrc[2 * i + 1] = a1; |
emh203 | 0:3d9c67d97d6f | 280 | |
emh203 | 0:3d9c67d97d6f | 281 | pSrc[2 * l] = p0 + p1; |
emh203 | 0:3d9c67d97d6f | 282 | pSrc[2 * l + 1] = p2 - p3; |
emh203 | 0:3d9c67d97d6f | 283 | |
emh203 | 0:3d9c67d97d6f | 284 | i += n1; |
emh203 | 0:3d9c67d97d6f | 285 | } while(i < fftLen); |
emh203 | 0:3d9c67d97d6f | 286 | j++; |
emh203 | 0:3d9c67d97d6f | 287 | } while(j < n2); |
emh203 | 0:3d9c67d97d6f | 288 | twidCoefModifier <<= 1u; |
emh203 | 0:3d9c67d97d6f | 289 | } |
emh203 | 0:3d9c67d97d6f | 290 | |
emh203 | 0:3d9c67d97d6f | 291 | #endif // #ifndef ARM_MATH_CM0_FAMILY |
emh203 | 0:3d9c67d97d6f | 292 | |
emh203 | 0:3d9c67d97d6f | 293 | } |
emh203 | 0:3d9c67d97d6f | 294 | |
emh203 | 0:3d9c67d97d6f | 295 | |
emh203 | 0:3d9c67d97d6f | 296 | void arm_radix2_butterfly_inverse_f32( |
emh203 | 0:3d9c67d97d6f | 297 | float32_t * pSrc, |
emh203 | 0:3d9c67d97d6f | 298 | uint32_t fftLen, |
emh203 | 0:3d9c67d97d6f | 299 | float32_t * pCoef, |
emh203 | 0:3d9c67d97d6f | 300 | uint16_t twidCoefModifier, |
emh203 | 0:3d9c67d97d6f | 301 | float32_t onebyfftLen) |
emh203 | 0:3d9c67d97d6f | 302 | { |
emh203 | 0:3d9c67d97d6f | 303 | |
emh203 | 0:3d9c67d97d6f | 304 | uint32_t i, j, k, l; |
emh203 | 0:3d9c67d97d6f | 305 | uint32_t n1, n2, ia; |
emh203 | 0:3d9c67d97d6f | 306 | float32_t xt, yt, cosVal, sinVal; |
emh203 | 0:3d9c67d97d6f | 307 | float32_t p0, p1, p2, p3; |
emh203 | 0:3d9c67d97d6f | 308 | float32_t a0, a1; |
emh203 | 0:3d9c67d97d6f | 309 | |
emh203 | 0:3d9c67d97d6f | 310 | #ifndef ARM_MATH_CM0_FAMILY |
emh203 | 0:3d9c67d97d6f | 311 | |
emh203 | 0:3d9c67d97d6f | 312 | n2 = fftLen >> 1; |
emh203 | 0:3d9c67d97d6f | 313 | ia = 0; |
emh203 | 0:3d9c67d97d6f | 314 | |
emh203 | 0:3d9c67d97d6f | 315 | // loop for groups |
emh203 | 0:3d9c67d97d6f | 316 | for (i = 0; i < n2; i++) |
emh203 | 0:3d9c67d97d6f | 317 | { |
emh203 | 0:3d9c67d97d6f | 318 | cosVal = pCoef[ia * 2]; |
emh203 | 0:3d9c67d97d6f | 319 | sinVal = pCoef[(ia * 2) + 1]; |
emh203 | 0:3d9c67d97d6f | 320 | ia += twidCoefModifier; |
emh203 | 0:3d9c67d97d6f | 321 | |
emh203 | 0:3d9c67d97d6f | 322 | l = i + n2; |
emh203 | 0:3d9c67d97d6f | 323 | a0 = pSrc[2 * i] + pSrc[2 * l]; |
emh203 | 0:3d9c67d97d6f | 324 | xt = pSrc[2 * i] - pSrc[2 * l]; |
emh203 | 0:3d9c67d97d6f | 325 | |
emh203 | 0:3d9c67d97d6f | 326 | yt = pSrc[2 * i + 1] - pSrc[2 * l + 1]; |
emh203 | 0:3d9c67d97d6f | 327 | a1 = pSrc[2 * l + 1] + pSrc[2 * i + 1]; |
emh203 | 0:3d9c67d97d6f | 328 | |
emh203 | 0:3d9c67d97d6f | 329 | p0 = xt * cosVal; |
emh203 | 0:3d9c67d97d6f | 330 | p1 = yt * sinVal; |
emh203 | 0:3d9c67d97d6f | 331 | p2 = yt * cosVal; |
emh203 | 0:3d9c67d97d6f | 332 | p3 = xt * sinVal; |
emh203 | 0:3d9c67d97d6f | 333 | |
emh203 | 0:3d9c67d97d6f | 334 | pSrc[2 * i] = a0; |
emh203 | 0:3d9c67d97d6f | 335 | pSrc[2 * i + 1] = a1; |
emh203 | 0:3d9c67d97d6f | 336 | |
emh203 | 0:3d9c67d97d6f | 337 | pSrc[2 * l] = p0 - p1; |
emh203 | 0:3d9c67d97d6f | 338 | pSrc[2 * l + 1] = p2 + p3; |
emh203 | 0:3d9c67d97d6f | 339 | } // groups loop end |
emh203 | 0:3d9c67d97d6f | 340 | |
emh203 | 0:3d9c67d97d6f | 341 | twidCoefModifier <<= 1u; |
emh203 | 0:3d9c67d97d6f | 342 | |
emh203 | 0:3d9c67d97d6f | 343 | // loop for stage |
emh203 | 0:3d9c67d97d6f | 344 | for (k = fftLen / 2; k > 2; k = k >> 1) |
emh203 | 0:3d9c67d97d6f | 345 | { |
emh203 | 0:3d9c67d97d6f | 346 | n1 = n2; |
emh203 | 0:3d9c67d97d6f | 347 | n2 = n2 >> 1; |
emh203 | 0:3d9c67d97d6f | 348 | ia = 0; |
emh203 | 0:3d9c67d97d6f | 349 | |
emh203 | 0:3d9c67d97d6f | 350 | // loop for groups |
emh203 | 0:3d9c67d97d6f | 351 | j = 0; |
emh203 | 0:3d9c67d97d6f | 352 | do |
emh203 | 0:3d9c67d97d6f | 353 | { |
emh203 | 0:3d9c67d97d6f | 354 | cosVal = pCoef[ia * 2]; |
emh203 | 0:3d9c67d97d6f | 355 | sinVal = pCoef[(ia * 2) + 1]; |
emh203 | 0:3d9c67d97d6f | 356 | ia += twidCoefModifier; |
emh203 | 0:3d9c67d97d6f | 357 | |
emh203 | 0:3d9c67d97d6f | 358 | // loop for butterfly |
emh203 | 0:3d9c67d97d6f | 359 | i = j; |
emh203 | 0:3d9c67d97d6f | 360 | do |
emh203 | 0:3d9c67d97d6f | 361 | { |
emh203 | 0:3d9c67d97d6f | 362 | l = i + n2; |
emh203 | 0:3d9c67d97d6f | 363 | a0 = pSrc[2 * i] + pSrc[2 * l]; |
emh203 | 0:3d9c67d97d6f | 364 | xt = pSrc[2 * i] - pSrc[2 * l]; |
emh203 | 0:3d9c67d97d6f | 365 | |
emh203 | 0:3d9c67d97d6f | 366 | yt = pSrc[2 * i + 1] - pSrc[2 * l + 1]; |
emh203 | 0:3d9c67d97d6f | 367 | a1 = pSrc[2 * l + 1] + pSrc[2 * i + 1]; |
emh203 | 0:3d9c67d97d6f | 368 | |
emh203 | 0:3d9c67d97d6f | 369 | p0 = xt * cosVal; |
emh203 | 0:3d9c67d97d6f | 370 | p1 = yt * sinVal; |
emh203 | 0:3d9c67d97d6f | 371 | p2 = yt * cosVal; |
emh203 | 0:3d9c67d97d6f | 372 | p3 = xt * sinVal; |
emh203 | 0:3d9c67d97d6f | 373 | |
emh203 | 0:3d9c67d97d6f | 374 | pSrc[2 * i] = a0; |
emh203 | 0:3d9c67d97d6f | 375 | pSrc[2 * i + 1] = a1; |
emh203 | 0:3d9c67d97d6f | 376 | |
emh203 | 0:3d9c67d97d6f | 377 | pSrc[2 * l] = p0 - p1; |
emh203 | 0:3d9c67d97d6f | 378 | pSrc[2 * l + 1] = p2 + p3; |
emh203 | 0:3d9c67d97d6f | 379 | |
emh203 | 0:3d9c67d97d6f | 380 | i += n1; |
emh203 | 0:3d9c67d97d6f | 381 | } while( i < fftLen ); // butterfly loop end |
emh203 | 0:3d9c67d97d6f | 382 | j++; |
emh203 | 0:3d9c67d97d6f | 383 | } while(j < n2); // groups loop end |
emh203 | 0:3d9c67d97d6f | 384 | |
emh203 | 0:3d9c67d97d6f | 385 | twidCoefModifier <<= 1u; |
emh203 | 0:3d9c67d97d6f | 386 | } // stages loop end |
emh203 | 0:3d9c67d97d6f | 387 | |
emh203 | 0:3d9c67d97d6f | 388 | // loop for butterfly |
emh203 | 0:3d9c67d97d6f | 389 | for (i = 0; i < fftLen; i += 2) |
emh203 | 0:3d9c67d97d6f | 390 | { |
emh203 | 0:3d9c67d97d6f | 391 | a0 = pSrc[2 * i] + pSrc[2 * i + 2]; |
emh203 | 0:3d9c67d97d6f | 392 | xt = pSrc[2 * i] - pSrc[2 * i + 2]; |
emh203 | 0:3d9c67d97d6f | 393 | |
emh203 | 0:3d9c67d97d6f | 394 | a1 = pSrc[2 * i + 3] + pSrc[2 * i + 1]; |
emh203 | 0:3d9c67d97d6f | 395 | yt = pSrc[2 * i + 1] - pSrc[2 * i + 3]; |
emh203 | 0:3d9c67d97d6f | 396 | |
emh203 | 0:3d9c67d97d6f | 397 | p0 = a0 * onebyfftLen; |
emh203 | 0:3d9c67d97d6f | 398 | p2 = xt * onebyfftLen; |
emh203 | 0:3d9c67d97d6f | 399 | p1 = a1 * onebyfftLen; |
emh203 | 0:3d9c67d97d6f | 400 | p3 = yt * onebyfftLen; |
emh203 | 0:3d9c67d97d6f | 401 | |
emh203 | 0:3d9c67d97d6f | 402 | pSrc[2 * i] = p0; |
emh203 | 0:3d9c67d97d6f | 403 | pSrc[2 * i + 1] = p1; |
emh203 | 0:3d9c67d97d6f | 404 | pSrc[2 * i + 2] = p2; |
emh203 | 0:3d9c67d97d6f | 405 | pSrc[2 * i + 3] = p3; |
emh203 | 0:3d9c67d97d6f | 406 | } // butterfly loop end |
emh203 | 0:3d9c67d97d6f | 407 | |
emh203 | 0:3d9c67d97d6f | 408 | #else |
emh203 | 0:3d9c67d97d6f | 409 | |
emh203 | 0:3d9c67d97d6f | 410 | n2 = fftLen; |
emh203 | 0:3d9c67d97d6f | 411 | |
emh203 | 0:3d9c67d97d6f | 412 | // loop for stage |
emh203 | 0:3d9c67d97d6f | 413 | for (k = fftLen; k > 2; k = k >> 1) |
emh203 | 0:3d9c67d97d6f | 414 | { |
emh203 | 0:3d9c67d97d6f | 415 | n1 = n2; |
emh203 | 0:3d9c67d97d6f | 416 | n2 = n2 >> 1; |
emh203 | 0:3d9c67d97d6f | 417 | ia = 0; |
emh203 | 0:3d9c67d97d6f | 418 | |
emh203 | 0:3d9c67d97d6f | 419 | // loop for groups |
emh203 | 0:3d9c67d97d6f | 420 | j = 0; |
emh203 | 0:3d9c67d97d6f | 421 | do |
emh203 | 0:3d9c67d97d6f | 422 | { |
emh203 | 0:3d9c67d97d6f | 423 | cosVal = pCoef[ia * 2]; |
emh203 | 0:3d9c67d97d6f | 424 | sinVal = pCoef[(ia * 2) + 1]; |
emh203 | 0:3d9c67d97d6f | 425 | ia = ia + twidCoefModifier; |
emh203 | 0:3d9c67d97d6f | 426 | |
emh203 | 0:3d9c67d97d6f | 427 | // loop for butterfly |
emh203 | 0:3d9c67d97d6f | 428 | i = j; |
emh203 | 0:3d9c67d97d6f | 429 | do |
emh203 | 0:3d9c67d97d6f | 430 | { |
emh203 | 0:3d9c67d97d6f | 431 | l = i + n2; |
emh203 | 0:3d9c67d97d6f | 432 | a0 = pSrc[2 * i] + pSrc[2 * l]; |
emh203 | 0:3d9c67d97d6f | 433 | xt = pSrc[2 * i] - pSrc[2 * l]; |
emh203 | 0:3d9c67d97d6f | 434 | |
emh203 | 0:3d9c67d97d6f | 435 | yt = pSrc[2 * i + 1] - pSrc[2 * l + 1]; |
emh203 | 0:3d9c67d97d6f | 436 | a1 = pSrc[2 * l + 1] + pSrc[2 * i + 1]; |
emh203 | 0:3d9c67d97d6f | 437 | |
emh203 | 0:3d9c67d97d6f | 438 | p0 = xt * cosVal; |
emh203 | 0:3d9c67d97d6f | 439 | p1 = yt * sinVal; |
emh203 | 0:3d9c67d97d6f | 440 | p2 = yt * cosVal; |
emh203 | 0:3d9c67d97d6f | 441 | p3 = xt * sinVal; |
emh203 | 0:3d9c67d97d6f | 442 | |
emh203 | 0:3d9c67d97d6f | 443 | pSrc[2 * i] = a0; |
emh203 | 0:3d9c67d97d6f | 444 | pSrc[2 * i + 1] = a1; |
emh203 | 0:3d9c67d97d6f | 445 | |
emh203 | 0:3d9c67d97d6f | 446 | pSrc[2 * l] = p0 - p1; |
emh203 | 0:3d9c67d97d6f | 447 | pSrc[2 * l + 1] = p2 + p3; |
emh203 | 0:3d9c67d97d6f | 448 | |
emh203 | 0:3d9c67d97d6f | 449 | i += n1; |
emh203 | 0:3d9c67d97d6f | 450 | } while( i < fftLen ); // butterfly loop end |
emh203 | 0:3d9c67d97d6f | 451 | j++; |
emh203 | 0:3d9c67d97d6f | 452 | } while( j < n2 ); // groups loop end |
emh203 | 0:3d9c67d97d6f | 453 | |
emh203 | 0:3d9c67d97d6f | 454 | twidCoefModifier = twidCoefModifier << 1u; |
emh203 | 0:3d9c67d97d6f | 455 | } // stages loop end |
emh203 | 0:3d9c67d97d6f | 456 | |
emh203 | 0:3d9c67d97d6f | 457 | n1 = n2; |
emh203 | 0:3d9c67d97d6f | 458 | n2 = n2 >> 1; |
emh203 | 0:3d9c67d97d6f | 459 | |
emh203 | 0:3d9c67d97d6f | 460 | // loop for butterfly |
emh203 | 0:3d9c67d97d6f | 461 | for (i = 0; i < fftLen; i += n1) |
emh203 | 0:3d9c67d97d6f | 462 | { |
emh203 | 0:3d9c67d97d6f | 463 | l = i + n2; |
emh203 | 0:3d9c67d97d6f | 464 | |
emh203 | 0:3d9c67d97d6f | 465 | a0 = pSrc[2 * i] + pSrc[2 * l]; |
emh203 | 0:3d9c67d97d6f | 466 | xt = pSrc[2 * i] - pSrc[2 * l]; |
emh203 | 0:3d9c67d97d6f | 467 | |
emh203 | 0:3d9c67d97d6f | 468 | a1 = pSrc[2 * l + 1] + pSrc[2 * i + 1]; |
emh203 | 0:3d9c67d97d6f | 469 | yt = pSrc[2 * i + 1] - pSrc[2 * l + 1]; |
emh203 | 0:3d9c67d97d6f | 470 | |
emh203 | 0:3d9c67d97d6f | 471 | p0 = a0 * onebyfftLen; |
emh203 | 0:3d9c67d97d6f | 472 | p2 = xt * onebyfftLen; |
emh203 | 0:3d9c67d97d6f | 473 | p1 = a1 * onebyfftLen; |
emh203 | 0:3d9c67d97d6f | 474 | p3 = yt * onebyfftLen; |
emh203 | 0:3d9c67d97d6f | 475 | |
emh203 | 0:3d9c67d97d6f | 476 | pSrc[2 * i] = p0; |
emh203 | 0:3d9c67d97d6f | 477 | pSrc[2u * l] = p2; |
emh203 | 0:3d9c67d97d6f | 478 | |
emh203 | 0:3d9c67d97d6f | 479 | pSrc[2 * i + 1] = p1; |
emh203 | 0:3d9c67d97d6f | 480 | pSrc[2u * l + 1u] = p3; |
emh203 | 0:3d9c67d97d6f | 481 | } // butterfly loop end |
emh203 | 0:3d9c67d97d6f | 482 | |
emh203 | 0:3d9c67d97d6f | 483 | #endif // #ifndef ARM_MATH_CM0_FAMILY |
emh203 | 0:3d9c67d97d6f | 484 | |
emh203 | 0:3d9c67d97d6f | 485 | } |