Eli Hughes / CMSIS_DSP_401

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_q31.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?

UserRevisionLine numberNew 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_q31.c
emh203 0:3d9c67d97d6f 9 *
emh203 0:3d9c67d97d6f 10 * Description: Radix-2 Decimation in Frequency CFFT & CIFFT Fixed 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_q31(
emh203 0:3d9c67d97d6f 45 q31_t * pSrc,
emh203 0:3d9c67d97d6f 46 uint32_t fftLen,
emh203 0:3d9c67d97d6f 47 q31_t * pCoef,
emh203 0:3d9c67d97d6f 48 uint16_t twidCoefModifier);
emh203 0:3d9c67d97d6f 49
emh203 0:3d9c67d97d6f 50 void arm_radix2_butterfly_inverse_q31(
emh203 0:3d9c67d97d6f 51 q31_t * pSrc,
emh203 0:3d9c67d97d6f 52 uint32_t fftLen,
emh203 0:3d9c67d97d6f 53 q31_t * pCoef,
emh203 0:3d9c67d97d6f 54 uint16_t twidCoefModifier);
emh203 0:3d9c67d97d6f 55
emh203 0:3d9c67d97d6f 56 void arm_bitreversal_q31(
emh203 0:3d9c67d97d6f 57 q31_t * pSrc,
emh203 0:3d9c67d97d6f 58 uint32_t fftLen,
emh203 0:3d9c67d97d6f 59 uint16_t bitRevFactor,
emh203 0:3d9c67d97d6f 60 uint16_t * pBitRevTab);
emh203 0:3d9c67d97d6f 61
emh203 0:3d9c67d97d6f 62 /**
emh203 0:3d9c67d97d6f 63 * @ingroup groupTransforms
emh203 0:3d9c67d97d6f 64 */
emh203 0:3d9c67d97d6f 65
emh203 0:3d9c67d97d6f 66 /**
emh203 0:3d9c67d97d6f 67 * @addtogroup ComplexFFT
emh203 0:3d9c67d97d6f 68 * @{
emh203 0:3d9c67d97d6f 69 */
emh203 0:3d9c67d97d6f 70
emh203 0:3d9c67d97d6f 71 /**
emh203 0:3d9c67d97d6f 72 * @details
emh203 0:3d9c67d97d6f 73 * @brief Processing function for the fixed-point CFFT/CIFFT.
emh203 0:3d9c67d97d6f 74 * @param[in] *S points to an instance of the fixed-point CFFT/CIFFT structure.
emh203 0:3d9c67d97d6f 75 * @param[in, out] *pSrc points to the complex data buffer of size <code>2*fftLen</code>. Processing occurs in-place.
emh203 0:3d9c67d97d6f 76 * @return none.
emh203 0:3d9c67d97d6f 77 */
emh203 0:3d9c67d97d6f 78
emh203 0:3d9c67d97d6f 79 void arm_cfft_radix2_q31(
emh203 0:3d9c67d97d6f 80 const arm_cfft_radix2_instance_q31 * S,
emh203 0:3d9c67d97d6f 81 q31_t * pSrc)
emh203 0:3d9c67d97d6f 82 {
emh203 0:3d9c67d97d6f 83
emh203 0:3d9c67d97d6f 84 if(S->ifftFlag == 1u)
emh203 0:3d9c67d97d6f 85 {
emh203 0:3d9c67d97d6f 86 arm_radix2_butterfly_inverse_q31(pSrc, S->fftLen,
emh203 0:3d9c67d97d6f 87 S->pTwiddle, S->twidCoefModifier);
emh203 0:3d9c67d97d6f 88 }
emh203 0:3d9c67d97d6f 89 else
emh203 0:3d9c67d97d6f 90 {
emh203 0:3d9c67d97d6f 91 arm_radix2_butterfly_q31(pSrc, S->fftLen,
emh203 0:3d9c67d97d6f 92 S->pTwiddle, S->twidCoefModifier);
emh203 0:3d9c67d97d6f 93 }
emh203 0:3d9c67d97d6f 94
emh203 0:3d9c67d97d6f 95 arm_bitreversal_q31(pSrc, S->fftLen, S->bitRevFactor, S->pBitRevTable);
emh203 0:3d9c67d97d6f 96 }
emh203 0:3d9c67d97d6f 97
emh203 0:3d9c67d97d6f 98 /**
emh203 0:3d9c67d97d6f 99 * @} end of ComplexFFT group
emh203 0:3d9c67d97d6f 100 */
emh203 0:3d9c67d97d6f 101
emh203 0:3d9c67d97d6f 102 void arm_radix2_butterfly_q31(
emh203 0:3d9c67d97d6f 103 q31_t * pSrc,
emh203 0:3d9c67d97d6f 104 uint32_t fftLen,
emh203 0:3d9c67d97d6f 105 q31_t * pCoef,
emh203 0:3d9c67d97d6f 106 uint16_t twidCoefModifier)
emh203 0:3d9c67d97d6f 107 {
emh203 0:3d9c67d97d6f 108
emh203 0:3d9c67d97d6f 109 unsigned i, j, k, l, m;
emh203 0:3d9c67d97d6f 110 unsigned n1, n2, ia;
emh203 0:3d9c67d97d6f 111 q31_t xt, yt, cosVal, sinVal;
emh203 0:3d9c67d97d6f 112 q31_t p0, p1;
emh203 0:3d9c67d97d6f 113
emh203 0:3d9c67d97d6f 114 //N = fftLen;
emh203 0:3d9c67d97d6f 115 n2 = fftLen;
emh203 0:3d9c67d97d6f 116
emh203 0:3d9c67d97d6f 117 n1 = n2;
emh203 0:3d9c67d97d6f 118 n2 = n2 >> 1;
emh203 0:3d9c67d97d6f 119 ia = 0;
emh203 0:3d9c67d97d6f 120
emh203 0:3d9c67d97d6f 121 // loop for groups
emh203 0:3d9c67d97d6f 122 for (i = 0; i < n2; i++)
emh203 0:3d9c67d97d6f 123 {
emh203 0:3d9c67d97d6f 124 cosVal = pCoef[ia * 2];
emh203 0:3d9c67d97d6f 125 sinVal = pCoef[(ia * 2) + 1];
emh203 0:3d9c67d97d6f 126 ia = ia + twidCoefModifier;
emh203 0:3d9c67d97d6f 127
emh203 0:3d9c67d97d6f 128 l = i + n2;
emh203 0:3d9c67d97d6f 129 xt = (pSrc[2 * i] >> 1u) - (pSrc[2 * l] >> 1u);
emh203 0:3d9c67d97d6f 130 pSrc[2 * i] = ((pSrc[2 * i] >> 1u) + (pSrc[2 * l] >> 1u)) >> 1u;
emh203 0:3d9c67d97d6f 131
emh203 0:3d9c67d97d6f 132 yt = (pSrc[2 * i + 1] >> 1u) - (pSrc[2 * l + 1] >> 1u);
emh203 0:3d9c67d97d6f 133 pSrc[2 * i + 1] =
emh203 0:3d9c67d97d6f 134 ((pSrc[2 * l + 1] >> 1u) + (pSrc[2 * i + 1] >> 1u)) >> 1u;
emh203 0:3d9c67d97d6f 135
emh203 0:3d9c67d97d6f 136 mult_32x32_keep32_R(p0, xt, cosVal);
emh203 0:3d9c67d97d6f 137 mult_32x32_keep32_R(p1, yt, cosVal);
emh203 0:3d9c67d97d6f 138 multAcc_32x32_keep32_R(p0, yt, sinVal);
emh203 0:3d9c67d97d6f 139 multSub_32x32_keep32_R(p1, xt, sinVal);
emh203 0:3d9c67d97d6f 140
emh203 0:3d9c67d97d6f 141 pSrc[2u * l] = p0;
emh203 0:3d9c67d97d6f 142 pSrc[2u * l + 1u] = p1;
emh203 0:3d9c67d97d6f 143
emh203 0:3d9c67d97d6f 144 } // groups loop end
emh203 0:3d9c67d97d6f 145
emh203 0:3d9c67d97d6f 146 twidCoefModifier <<= 1u;
emh203 0:3d9c67d97d6f 147
emh203 0:3d9c67d97d6f 148 // loop for stage
emh203 0:3d9c67d97d6f 149 for (k = fftLen / 2; k > 2; k = k >> 1)
emh203 0:3d9c67d97d6f 150 {
emh203 0:3d9c67d97d6f 151 n1 = n2;
emh203 0:3d9c67d97d6f 152 n2 = n2 >> 1;
emh203 0:3d9c67d97d6f 153 ia = 0;
emh203 0:3d9c67d97d6f 154
emh203 0:3d9c67d97d6f 155 // loop for groups
emh203 0:3d9c67d97d6f 156 for (j = 0; j < n2; j++)
emh203 0:3d9c67d97d6f 157 {
emh203 0:3d9c67d97d6f 158 cosVal = pCoef[ia * 2];
emh203 0:3d9c67d97d6f 159 sinVal = pCoef[(ia * 2) + 1];
emh203 0:3d9c67d97d6f 160 ia = ia + twidCoefModifier;
emh203 0:3d9c67d97d6f 161
emh203 0:3d9c67d97d6f 162 // loop for butterfly
emh203 0:3d9c67d97d6f 163 i = j;
emh203 0:3d9c67d97d6f 164 m = fftLen / n1;
emh203 0:3d9c67d97d6f 165 do
emh203 0:3d9c67d97d6f 166 {
emh203 0:3d9c67d97d6f 167 l = i + n2;
emh203 0:3d9c67d97d6f 168 xt = pSrc[2 * i] - pSrc[2 * l];
emh203 0:3d9c67d97d6f 169 pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]) >> 1u;
emh203 0:3d9c67d97d6f 170
emh203 0:3d9c67d97d6f 171 yt = pSrc[2 * i + 1] - pSrc[2 * l + 1];
emh203 0:3d9c67d97d6f 172 pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]) >> 1u;
emh203 0:3d9c67d97d6f 173
emh203 0:3d9c67d97d6f 174 mult_32x32_keep32_R(p0, xt, cosVal);
emh203 0:3d9c67d97d6f 175 mult_32x32_keep32_R(p1, yt, cosVal);
emh203 0:3d9c67d97d6f 176 multAcc_32x32_keep32_R(p0, yt, sinVal);
emh203 0:3d9c67d97d6f 177 multSub_32x32_keep32_R(p1, xt, sinVal);
emh203 0:3d9c67d97d6f 178
emh203 0:3d9c67d97d6f 179 pSrc[2u * l] = p0;
emh203 0:3d9c67d97d6f 180 pSrc[2u * l + 1u] = p1;
emh203 0:3d9c67d97d6f 181 i += n1;
emh203 0:3d9c67d97d6f 182 m--;
emh203 0:3d9c67d97d6f 183 } while( m > 0); // butterfly loop end
emh203 0:3d9c67d97d6f 184
emh203 0:3d9c67d97d6f 185 } // groups loop end
emh203 0:3d9c67d97d6f 186
emh203 0:3d9c67d97d6f 187 twidCoefModifier <<= 1u;
emh203 0:3d9c67d97d6f 188 } // stages loop end
emh203 0:3d9c67d97d6f 189
emh203 0:3d9c67d97d6f 190 n1 = n2;
emh203 0:3d9c67d97d6f 191 n2 = n2 >> 1;
emh203 0:3d9c67d97d6f 192 ia = 0;
emh203 0:3d9c67d97d6f 193
emh203 0:3d9c67d97d6f 194 cosVal = pCoef[ia * 2];
emh203 0:3d9c67d97d6f 195 sinVal = pCoef[(ia * 2) + 1];
emh203 0:3d9c67d97d6f 196 ia = ia + twidCoefModifier;
emh203 0:3d9c67d97d6f 197
emh203 0:3d9c67d97d6f 198 // loop for butterfly
emh203 0:3d9c67d97d6f 199 for (i = 0; i < fftLen; i += n1)
emh203 0:3d9c67d97d6f 200 {
emh203 0:3d9c67d97d6f 201 l = i + n2;
emh203 0:3d9c67d97d6f 202 xt = pSrc[2 * i] - pSrc[2 * l];
emh203 0:3d9c67d97d6f 203 pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]);
emh203 0:3d9c67d97d6f 204
emh203 0:3d9c67d97d6f 205 yt = pSrc[2 * i + 1] - pSrc[2 * l + 1];
emh203 0:3d9c67d97d6f 206 pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]);
emh203 0:3d9c67d97d6f 207
emh203 0:3d9c67d97d6f 208 pSrc[2u * l] = xt;
emh203 0:3d9c67d97d6f 209
emh203 0:3d9c67d97d6f 210 pSrc[2u * l + 1u] = yt;
emh203 0:3d9c67d97d6f 211
emh203 0:3d9c67d97d6f 212 i += n1;
emh203 0:3d9c67d97d6f 213 l = i + n2;
emh203 0:3d9c67d97d6f 214
emh203 0:3d9c67d97d6f 215 xt = pSrc[2 * i] - pSrc[2 * l];
emh203 0:3d9c67d97d6f 216 pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]);
emh203 0:3d9c67d97d6f 217
emh203 0:3d9c67d97d6f 218 yt = pSrc[2 * i + 1] - pSrc[2 * l + 1];
emh203 0:3d9c67d97d6f 219 pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]);
emh203 0:3d9c67d97d6f 220
emh203 0:3d9c67d97d6f 221 pSrc[2u * l] = xt;
emh203 0:3d9c67d97d6f 222
emh203 0:3d9c67d97d6f 223 pSrc[2u * l + 1u] = yt;
emh203 0:3d9c67d97d6f 224
emh203 0:3d9c67d97d6f 225 } // butterfly loop end
emh203 0:3d9c67d97d6f 226
emh203 0:3d9c67d97d6f 227 }
emh203 0:3d9c67d97d6f 228
emh203 0:3d9c67d97d6f 229
emh203 0:3d9c67d97d6f 230 void arm_radix2_butterfly_inverse_q31(
emh203 0:3d9c67d97d6f 231 q31_t * pSrc,
emh203 0:3d9c67d97d6f 232 uint32_t fftLen,
emh203 0:3d9c67d97d6f 233 q31_t * pCoef,
emh203 0:3d9c67d97d6f 234 uint16_t twidCoefModifier)
emh203 0:3d9c67d97d6f 235 {
emh203 0:3d9c67d97d6f 236
emh203 0:3d9c67d97d6f 237 unsigned i, j, k, l;
emh203 0:3d9c67d97d6f 238 unsigned n1, n2, ia;
emh203 0:3d9c67d97d6f 239 q31_t xt, yt, cosVal, sinVal;
emh203 0:3d9c67d97d6f 240 q31_t p0, p1;
emh203 0:3d9c67d97d6f 241
emh203 0:3d9c67d97d6f 242 //N = fftLen;
emh203 0:3d9c67d97d6f 243 n2 = fftLen;
emh203 0:3d9c67d97d6f 244
emh203 0:3d9c67d97d6f 245 n1 = n2;
emh203 0:3d9c67d97d6f 246 n2 = n2 >> 1;
emh203 0:3d9c67d97d6f 247 ia = 0;
emh203 0:3d9c67d97d6f 248
emh203 0:3d9c67d97d6f 249 // loop for groups
emh203 0:3d9c67d97d6f 250 for (i = 0; i < n2; i++)
emh203 0:3d9c67d97d6f 251 {
emh203 0:3d9c67d97d6f 252 cosVal = pCoef[ia * 2];
emh203 0:3d9c67d97d6f 253 sinVal = pCoef[(ia * 2) + 1];
emh203 0:3d9c67d97d6f 254 ia = ia + twidCoefModifier;
emh203 0:3d9c67d97d6f 255
emh203 0:3d9c67d97d6f 256 l = i + n2;
emh203 0:3d9c67d97d6f 257 xt = (pSrc[2 * i] >> 1u) - (pSrc[2 * l] >> 1u);
emh203 0:3d9c67d97d6f 258 pSrc[2 * i] = ((pSrc[2 * i] >> 1u) + (pSrc[2 * l] >> 1u)) >> 1u;
emh203 0:3d9c67d97d6f 259
emh203 0:3d9c67d97d6f 260 yt = (pSrc[2 * i + 1] >> 1u) - (pSrc[2 * l + 1] >> 1u);
emh203 0:3d9c67d97d6f 261 pSrc[2 * i + 1] =
emh203 0:3d9c67d97d6f 262 ((pSrc[2 * l + 1] >> 1u) + (pSrc[2 * i + 1] >> 1u)) >> 1u;
emh203 0:3d9c67d97d6f 263
emh203 0:3d9c67d97d6f 264 mult_32x32_keep32_R(p0, xt, cosVal);
emh203 0:3d9c67d97d6f 265 mult_32x32_keep32_R(p1, yt, cosVal);
emh203 0:3d9c67d97d6f 266 multSub_32x32_keep32_R(p0, yt, sinVal);
emh203 0:3d9c67d97d6f 267 multAcc_32x32_keep32_R(p1, xt, sinVal);
emh203 0:3d9c67d97d6f 268
emh203 0:3d9c67d97d6f 269 pSrc[2u * l] = p0;
emh203 0:3d9c67d97d6f 270 pSrc[2u * l + 1u] = p1;
emh203 0:3d9c67d97d6f 271 } // groups loop end
emh203 0:3d9c67d97d6f 272
emh203 0:3d9c67d97d6f 273 twidCoefModifier = twidCoefModifier << 1u;
emh203 0:3d9c67d97d6f 274
emh203 0:3d9c67d97d6f 275 // loop for stage
emh203 0:3d9c67d97d6f 276 for (k = fftLen / 2; k > 2; k = k >> 1)
emh203 0:3d9c67d97d6f 277 {
emh203 0:3d9c67d97d6f 278 n1 = n2;
emh203 0:3d9c67d97d6f 279 n2 = n2 >> 1;
emh203 0:3d9c67d97d6f 280 ia = 0;
emh203 0:3d9c67d97d6f 281
emh203 0:3d9c67d97d6f 282 // loop for groups
emh203 0:3d9c67d97d6f 283 for (j = 0; j < n2; j++)
emh203 0:3d9c67d97d6f 284 {
emh203 0:3d9c67d97d6f 285 cosVal = pCoef[ia * 2];
emh203 0:3d9c67d97d6f 286 sinVal = pCoef[(ia * 2) + 1];
emh203 0:3d9c67d97d6f 287 ia = ia + twidCoefModifier;
emh203 0:3d9c67d97d6f 288
emh203 0:3d9c67d97d6f 289 // loop for butterfly
emh203 0:3d9c67d97d6f 290 for (i = j; i < fftLen; i += n1)
emh203 0:3d9c67d97d6f 291 {
emh203 0:3d9c67d97d6f 292 l = i + n2;
emh203 0:3d9c67d97d6f 293 xt = pSrc[2 * i] - pSrc[2 * l];
emh203 0:3d9c67d97d6f 294 pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]) >> 1u;
emh203 0:3d9c67d97d6f 295
emh203 0:3d9c67d97d6f 296 yt = pSrc[2 * i + 1] - pSrc[2 * l + 1];
emh203 0:3d9c67d97d6f 297 pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]) >> 1u;
emh203 0:3d9c67d97d6f 298
emh203 0:3d9c67d97d6f 299 mult_32x32_keep32_R(p0, xt, cosVal);
emh203 0:3d9c67d97d6f 300 mult_32x32_keep32_R(p1, yt, cosVal);
emh203 0:3d9c67d97d6f 301 multSub_32x32_keep32_R(p0, yt, sinVal);
emh203 0:3d9c67d97d6f 302 multAcc_32x32_keep32_R(p1, xt, sinVal);
emh203 0:3d9c67d97d6f 303
emh203 0:3d9c67d97d6f 304 pSrc[2u * l] = p0;
emh203 0:3d9c67d97d6f 305 pSrc[2u * l + 1u] = p1;
emh203 0:3d9c67d97d6f 306 } // butterfly loop end
emh203 0:3d9c67d97d6f 307
emh203 0:3d9c67d97d6f 308 } // groups loop end
emh203 0:3d9c67d97d6f 309
emh203 0:3d9c67d97d6f 310 twidCoefModifier = twidCoefModifier << 1u;
emh203 0:3d9c67d97d6f 311 } // stages loop end
emh203 0:3d9c67d97d6f 312
emh203 0:3d9c67d97d6f 313 n1 = n2;
emh203 0:3d9c67d97d6f 314 n2 = n2 >> 1;
emh203 0:3d9c67d97d6f 315 ia = 0;
emh203 0:3d9c67d97d6f 316
emh203 0:3d9c67d97d6f 317 cosVal = pCoef[ia * 2];
emh203 0:3d9c67d97d6f 318 sinVal = pCoef[(ia * 2) + 1];
emh203 0:3d9c67d97d6f 319 ia = ia + twidCoefModifier;
emh203 0:3d9c67d97d6f 320
emh203 0:3d9c67d97d6f 321 // loop for butterfly
emh203 0:3d9c67d97d6f 322 for (i = 0; i < fftLen; i += n1)
emh203 0:3d9c67d97d6f 323 {
emh203 0:3d9c67d97d6f 324 l = i + n2;
emh203 0:3d9c67d97d6f 325 xt = pSrc[2 * i] - pSrc[2 * l];
emh203 0:3d9c67d97d6f 326 pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]);
emh203 0:3d9c67d97d6f 327
emh203 0:3d9c67d97d6f 328 yt = pSrc[2 * i + 1] - pSrc[2 * l + 1];
emh203 0:3d9c67d97d6f 329 pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]);
emh203 0:3d9c67d97d6f 330
emh203 0:3d9c67d97d6f 331 pSrc[2u * l] = xt;
emh203 0:3d9c67d97d6f 332
emh203 0:3d9c67d97d6f 333 pSrc[2u * l + 1u] = yt;
emh203 0:3d9c67d97d6f 334
emh203 0:3d9c67d97d6f 335 i += n1;
emh203 0:3d9c67d97d6f 336 l = i + n2;
emh203 0:3d9c67d97d6f 337
emh203 0:3d9c67d97d6f 338 xt = pSrc[2 * i] - pSrc[2 * l];
emh203 0:3d9c67d97d6f 339 pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]);
emh203 0:3d9c67d97d6f 340
emh203 0:3d9c67d97d6f 341 yt = pSrc[2 * i + 1] - pSrc[2 * l + 1];
emh203 0:3d9c67d97d6f 342 pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]);
emh203 0:3d9c67d97d6f 343
emh203 0:3d9c67d97d6f 344 pSrc[2u * l] = xt;
emh203 0:3d9c67d97d6f 345
emh203 0:3d9c67d97d6f 346 pSrc[2u * l + 1u] = yt;
emh203 0:3d9c67d97d6f 347
emh203 0:3d9c67d97d6f 348 } // butterfly loop end
emh203 0:3d9c67d97d6f 349
emh203 0:3d9c67d97d6f 350 }