| /* ---------------------------------------------------------------------- |
| * Project: CMSIS DSP Library |
| * Title: arm_cfft_radix2_q31.c |
| * Description: Radix-2 Decimation in Frequency CFFT & CIFFT Fixed 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" |
| |
| void arm_radix2_butterfly_q31( |
| q31_t * pSrc, |
| uint32_t fftLen, |
| const q31_t * pCoef, |
| uint16_t twidCoefModifier); |
| |
| void arm_radix2_butterfly_inverse_q31( |
| q31_t * pSrc, |
| uint32_t fftLen, |
| const q31_t * pCoef, |
| uint16_t twidCoefModifier); |
| |
| void arm_bitreversal_q31( |
| q31_t * pSrc, |
| uint32_t fftLen, |
| uint16_t bitRevFactor, |
| const uint16_t * pBitRevTab); |
| |
| /** |
| @ingroup groupTransforms |
| */ |
| |
| /** |
| @addtogroup ComplexFFT |
| @{ |
| */ |
| |
| /** |
| @brief Processing function for the fixed-point CFFT/CIFFT. |
| @deprecated Do not use this function. It has been superseded by \ref arm_cfft_q31 and will be removed in the future. |
| @param[in] S points to an instance of the fixed-point CFFT/CIFFT structure |
| @param[in,out] pSrc points to the complex data buffer of size <code>2*fftLen</code>. Processing occurs in-place |
| @return none |
| */ |
| |
| void arm_cfft_radix2_q31( |
| const arm_cfft_radix2_instance_q31 * S, |
| q31_t * pSrc) |
| { |
| |
| if (S->ifftFlag == 1U) |
| { |
| arm_radix2_butterfly_inverse_q31(pSrc, S->fftLen, |
| S->pTwiddle, S->twidCoefModifier); |
| } |
| else |
| { |
| arm_radix2_butterfly_q31(pSrc, S->fftLen, |
| S->pTwiddle, S->twidCoefModifier); |
| } |
| |
| arm_bitreversal_q31(pSrc, S->fftLen, S->bitRevFactor, S->pBitRevTable); |
| } |
| |
| /** |
| @} end of ComplexFFT group |
| */ |
| |
| void arm_radix2_butterfly_q31( |
| q31_t * pSrc, |
| uint32_t fftLen, |
| const q31_t * pCoef, |
| uint16_t twidCoefModifier) |
| { |
| |
| unsigned i, j, k, l, m; |
| unsigned n1, n2, ia; |
| q31_t xt, yt, cosVal, sinVal; |
| q31_t p0, p1; |
| |
| //N = fftLen; |
| n2 = fftLen; |
| |
| n1 = n2; |
| n2 = n2 >> 1; |
| ia = 0; |
| |
| // loop for groups |
| for (i = 0; i < n2; i++) |
| { |
| cosVal = pCoef[ia * 2]; |
| sinVal = pCoef[(ia * 2) + 1]; |
| ia = ia + twidCoefModifier; |
| |
| l = i + n2; |
| xt = (pSrc[2 * i] >> 1U) - (pSrc[2 * l] >> 1U); |
| pSrc[2 * i] = ((pSrc[2 * i] >> 1U) + (pSrc[2 * l] >> 1U)) >> 1U; |
| |
| yt = (pSrc[2 * i + 1] >> 1U) - (pSrc[2 * l + 1] >> 1U); |
| pSrc[2 * i + 1] = |
| ((pSrc[2 * l + 1] >> 1U) + (pSrc[2 * i + 1] >> 1U)) >> 1U; |
| |
| mult_32x32_keep32_R(p0, xt, cosVal); |
| mult_32x32_keep32_R(p1, yt, cosVal); |
| multAcc_32x32_keep32_R(p0, yt, sinVal); |
| multSub_32x32_keep32_R(p1, xt, sinVal); |
| |
| pSrc[2U * l] = p0; |
| pSrc[2U * l + 1U] = p1; |
| |
| } // groups loop end |
| |
| twidCoefModifier <<= 1U; |
| |
| // loop for stage |
| for (k = fftLen / 2; k > 2; k = k >> 1) |
| { |
| n1 = n2; |
| n2 = n2 >> 1; |
| ia = 0; |
| |
| // loop for groups |
| for (j = 0; j < n2; j++) |
| { |
| cosVal = pCoef[ia * 2]; |
| sinVal = pCoef[(ia * 2) + 1]; |
| ia = ia + twidCoefModifier; |
| |
| // loop for butterfly |
| i = j; |
| m = fftLen / n1; |
| do |
| { |
| l = i + n2; |
| xt = pSrc[2 * i] - pSrc[2 * l]; |
| pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]) >> 1U; |
| |
| yt = pSrc[2 * i + 1] - pSrc[2 * l + 1]; |
| pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]) >> 1U; |
| |
| mult_32x32_keep32_R(p0, xt, cosVal); |
| mult_32x32_keep32_R(p1, yt, cosVal); |
| multAcc_32x32_keep32_R(p0, yt, sinVal); |
| multSub_32x32_keep32_R(p1, xt, sinVal); |
| |
| pSrc[2U * l] = p0; |
| pSrc[2U * l + 1U] = p1; |
| i += n1; |
| m--; |
| } while ( m > 0); // butterfly loop end |
| |
| } // groups loop end |
| |
| twidCoefModifier <<= 1U; |
| } // stages loop end |
| |
| n1 = n2; |
| n2 = n2 >> 1; |
| ia = 0; |
| |
| cosVal = pCoef[ia * 2]; |
| sinVal = pCoef[(ia * 2) + 1]; |
| ia = ia + twidCoefModifier; |
| |
| // loop for butterfly |
| for (i = 0; i < fftLen; i += n1) |
| { |
| l = i + n2; |
| xt = pSrc[2 * i] - pSrc[2 * l]; |
| pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]); |
| |
| yt = pSrc[2 * i + 1] - pSrc[2 * l + 1]; |
| pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]); |
| |
| pSrc[2U * l] = xt; |
| |
| pSrc[2U * l + 1U] = yt; |
| |
| i += n1; |
| l = i + n2; |
| |
| xt = pSrc[2 * i] - pSrc[2 * l]; |
| pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]); |
| |
| yt = pSrc[2 * i + 1] - pSrc[2 * l + 1]; |
| pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]); |
| |
| pSrc[2U * l] = xt; |
| |
| pSrc[2U * l + 1U] = yt; |
| |
| } // butterfly loop end |
| |
| } |
| |
| |
| void arm_radix2_butterfly_inverse_q31( |
| q31_t * pSrc, |
| uint32_t fftLen, |
| const q31_t * pCoef, |
| uint16_t twidCoefModifier) |
| { |
| |
| unsigned i, j, k, l; |
| unsigned n1, n2, ia; |
| q31_t xt, yt, cosVal, sinVal; |
| q31_t p0, p1; |
| |
| //N = fftLen; |
| n2 = fftLen; |
| |
| n1 = n2; |
| n2 = n2 >> 1; |
| ia = 0; |
| |
| // loop for groups |
| for (i = 0; i < n2; i++) |
| { |
| cosVal = pCoef[ia * 2]; |
| sinVal = pCoef[(ia * 2) + 1]; |
| ia = ia + twidCoefModifier; |
| |
| l = i + n2; |
| xt = (pSrc[2 * i] >> 1U) - (pSrc[2 * l] >> 1U); |
| pSrc[2 * i] = ((pSrc[2 * i] >> 1U) + (pSrc[2 * l] >> 1U)) >> 1U; |
| |
| yt = (pSrc[2 * i + 1] >> 1U) - (pSrc[2 * l + 1] >> 1U); |
| pSrc[2 * i + 1] = |
| ((pSrc[2 * l + 1] >> 1U) + (pSrc[2 * i + 1] >> 1U)) >> 1U; |
| |
| mult_32x32_keep32_R(p0, xt, cosVal); |
| mult_32x32_keep32_R(p1, yt, cosVal); |
| multSub_32x32_keep32_R(p0, yt, sinVal); |
| multAcc_32x32_keep32_R(p1, xt, sinVal); |
| |
| pSrc[2U * l] = p0; |
| pSrc[2U * l + 1U] = p1; |
| } // groups loop end |
| |
| twidCoefModifier = twidCoefModifier << 1U; |
| |
| // loop for stage |
| for (k = fftLen / 2; k > 2; k = k >> 1) |
| { |
| n1 = n2; |
| n2 = n2 >> 1; |
| ia = 0; |
| |
| // loop for groups |
| for (j = 0; j < n2; j++) |
| { |
| cosVal = pCoef[ia * 2]; |
| sinVal = pCoef[(ia * 2) + 1]; |
| ia = ia + twidCoefModifier; |
| |
| // loop for butterfly |
| for (i = j; i < fftLen; i += n1) |
| { |
| l = i + n2; |
| xt = pSrc[2 * i] - pSrc[2 * l]; |
| pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]) >> 1U; |
| |
| yt = pSrc[2 * i + 1] - pSrc[2 * l + 1]; |
| pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]) >> 1U; |
| |
| mult_32x32_keep32_R(p0, xt, cosVal); |
| mult_32x32_keep32_R(p1, yt, cosVal); |
| multSub_32x32_keep32_R(p0, yt, sinVal); |
| multAcc_32x32_keep32_R(p1, xt, sinVal); |
| |
| pSrc[2U * l] = p0; |
| pSrc[2U * l + 1U] = p1; |
| } // butterfly loop end |
| |
| } // groups loop end |
| |
| twidCoefModifier = twidCoefModifier << 1U; |
| } // stages loop end |
| |
| n1 = n2; |
| n2 = n2 >> 1; |
| ia = 0; |
| |
| cosVal = pCoef[ia * 2]; |
| sinVal = pCoef[(ia * 2) + 1]; |
| ia = ia + twidCoefModifier; |
| |
| // loop for butterfly |
| for (i = 0; i < fftLen; i += n1) |
| { |
| l = i + n2; |
| xt = pSrc[2 * i] - pSrc[2 * l]; |
| pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]); |
| |
| yt = pSrc[2 * i + 1] - pSrc[2 * l + 1]; |
| pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]); |
| |
| pSrc[2U * l] = xt; |
| |
| pSrc[2U * l + 1U] = yt; |
| |
| i += n1; |
| l = i + n2; |
| |
| xt = pSrc[2 * i] - pSrc[2 * l]; |
| pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]); |
| |
| yt = pSrc[2 * i + 1] - pSrc[2 * l + 1]; |
| pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]); |
| |
| pSrc[2U * l] = xt; |
| |
| pSrc[2U * l + 1U] = yt; |
| |
| } // butterfly loop end |
| |
| } |