From 86608c6770cf08c138a2bdab5855072f64be09ef Mon Sep 17 00:00:00 2001 From: joshua Date: Sat, 30 Dec 2023 23:54:31 -0500 Subject: initial commit --- .../DSP/Source/TransformFunctions/arm_cfft_f32.c | 629 +++++++++++++++++++++ 1 file changed, 629 insertions(+) create mode 100644 Drivers/CMSIS/DSP/Source/TransformFunctions/arm_cfft_f32.c (limited to 'Drivers/CMSIS/DSP/Source/TransformFunctions/arm_cfft_f32.c') diff --git a/Drivers/CMSIS/DSP/Source/TransformFunctions/arm_cfft_f32.c b/Drivers/CMSIS/DSP/Source/TransformFunctions/arm_cfft_f32.c new file mode 100644 index 0000000..15dbb8f --- /dev/null +++ b/Drivers/CMSIS/DSP/Source/TransformFunctions/arm_cfft_f32.c @@ -0,0 +1,629 @@ +/* ---------------------------------------------------------------------- + * Project: CMSIS DSP Library + * Title: arm_cfft_f32.c + * Description: Combined 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" + +extern void arm_radix8_butterfly_f32( + float32_t * pSrc, + uint16_t fftLen, + const float32_t * pCoef, + uint16_t twidCoefModifier); + +extern void arm_bitreversal_32( + uint32_t * pSrc, + const uint16_t bitRevLen, + const uint16_t * pBitRevTable); + +/** + @ingroup groupTransforms + */ + +/** + @defgroup ComplexFFT Complex FFT Functions + + @par + The Fast Fourier Transform (FFT) is an efficient algorithm for computing the + Discrete Fourier Transform (DFT). The FFT can be orders of magnitude faster + than the DFT, especially for long lengths. + The algorithms described in this section + operate on complex data. A separate set of functions is devoted to handling + of real sequences. + @par + There are separate algorithms for handling floating-point, Q15, and Q31 data + types. The algorithms available for each data type are described next. + @par + The FFT functions operate in-place. That is, the array holding the input data + will also be used to hold the corresponding result. The input data is complex + and contains 2*fftLen interleaved values as shown below. + 
{real[0], imag[0], real[1], imag[1], ...}
+ The FFT result will be contained in the same array and the frequency domain + values will have the same interleaving. + + @par Floating-point + The floating-point complex FFT uses a mixed-radix algorithm. Multiple radix-8 + stages are performed along with a single radix-2 or radix-4 stage, as needed. + The algorithm supports lengths of [16, 32, 64, ..., 4096] and each length uses + a different twiddle factor table. + @par + The function uses the standard FFT definition and output values may grow by a + factor of fftLen when computing the forward transform. The + inverse transform includes a scale of 1/fftLen as part of the + calculation and this matches the textbook definition of the inverse FFT. + @par + Pre-initialized data structures containing twiddle factors and bit reversal + tables are provided and defined in arm_const_structs.h. Include + this header in your function and then pass one of the constant structures as + an argument to arm_cfft_f32. For example: + @par + arm_cfft_f32(arm_cfft_sR_f32_len64, pSrc, 1, 1) + @par + computes a 64-point inverse complex FFT including bit reversal. + The data structures are treated as constant data and not modified during the + calculation. The same data structure can be reused for multiple transforms + including mixing forward and inverse transforms. + @par + Earlier releases of the library provided separate radix-2 and radix-4 + algorithms that operated on floating-point data. These functions are still + provided but are deprecated. The older functions are slower and less general + than the new functions. + @par + An example of initialization of the constants for the arm_cfft_f32 function follows: + @code + const static arm_cfft_instance_f32 *S; + ... + switch (length) { + case 16: + S = &arm_cfft_sR_f32_len16; + break; + case 32: + S = &arm_cfft_sR_f32_len32; + break; + case 64: + S = &arm_cfft_sR_f32_len64; + break; + case 128: + S = &arm_cfft_sR_f32_len128; + break; + case 256: + S = &arm_cfft_sR_f32_len256; + break; + case 512: + S = &arm_cfft_sR_f32_len512; + break; + case 1024: + S = &arm_cfft_sR_f32_len1024; + break; + case 2048: + S = &arm_cfft_sR_f32_len2048; + break; + case 4096: + S = &arm_cfft_sR_f32_len4096; + break; + } + @endcode + @par Q15 and Q31 + The floating-point complex FFT uses a mixed-radix algorithm. Multiple radix-4 + stages are performed along with a single radix-2 stage, as needed. + The algorithm supports lengths of [16, 32, 64, ..., 4096] and each length uses + a different twiddle factor table. + @par + The function uses the standard FFT definition and output values may grow by a + factor of fftLen when computing the forward transform. The + inverse transform includes a scale of 1/fftLen as part of the + calculation and this matches the textbook definition of the inverse FFT. + @par + Pre-initialized data structures containing twiddle factors and bit reversal + tables are provided and defined in arm_const_structs.h. Include + this header in your function and then pass one of the constant structures as + an argument to arm_cfft_q31. For example: + @par + arm_cfft_q31(arm_cfft_sR_q31_len64, pSrc, 1, 1) + @par + computes a 64-point inverse complex FFT including bit reversal. + The data structures are treated as constant data and not modified during the + calculation. The same data structure can be reused for multiple transforms + including mixing forward and inverse transforms. + @par + Earlier releases of the library provided separate radix-2 and radix-4 + algorithms that operated on floating-point data. These functions are still + provided but are deprecated. The older functions are slower and less general + than the new functions. + @par + An example of initialization of the constants for the arm_cfft_q31 function follows: + @code + const static arm_cfft_instance_q31 *S; + ... + switch (length) { + case 16: + S = &arm_cfft_sR_q31_len16; + break; + case 32: + S = &arm_cfft_sR_q31_len32; + break; + case 64: + S = &arm_cfft_sR_q31_len64; + break; + case 128: + S = &arm_cfft_sR_q31_len128; + break; + case 256: + S = &arm_cfft_sR_q31_len256; + break; + case 512: + S = &arm_cfft_sR_q31_len512; + break; + case 1024: + S = &arm_cfft_sR_q31_len1024; + break; + case 2048: + S = &arm_cfft_sR_q31_len2048; + break; + case 4096: + S = &arm_cfft_sR_q31_len4096; + break; + } + @endcode + + */ + +void arm_cfft_radix8by2_f32 (arm_cfft_instance_f32 * S, float32_t * p1) +{ + uint32_t L = S->fftLen; + float32_t * pCol1, * pCol2, * pMid1, * pMid2; + float32_t * p2 = p1 + L; + const float32_t * tw = (float32_t *) S->pTwiddle; + float32_t t1[4], t2[4], t3[4], t4[4], twR, twI; + float32_t m0, m1, m2, m3; + uint32_t l; + + pCol1 = p1; + pCol2 = p2; + + /* Define new length */ + L >>= 1; + + /* Initialize mid pointers */ + pMid1 = p1 + L; + pMid2 = p2 + L; + + /* do two dot Fourier transform */ + for (l = L >> 2; l > 0; l-- ) + { + t1[0] = p1[0]; + t1[1] = p1[1]; + t1[2] = p1[2]; + t1[3] = p1[3]; + + t2[0] = p2[0]; + t2[1] = p2[1]; + t2[2] = p2[2]; + t2[3] = p2[3]; + + t3[0] = pMid1[0]; + t3[1] = pMid1[1]; + t3[2] = pMid1[2]; + t3[3] = pMid1[3]; + + t4[0] = pMid2[0]; + t4[1] = pMid2[1]; + t4[2] = pMid2[2]; + t4[3] = pMid2[3]; + + *p1++ = t1[0] + t2[0]; + *p1++ = t1[1] + t2[1]; + *p1++ = t1[2] + t2[2]; + *p1++ = t1[3] + t2[3]; /* col 1 */ + + t2[0] = t1[0] - t2[0]; + t2[1] = t1[1] - t2[1]; + t2[2] = t1[2] - t2[2]; + t2[3] = t1[3] - t2[3]; /* for col 2 */ + + *pMid1++ = t3[0] + t4[0]; + *pMid1++ = t3[1] + t4[1]; + *pMid1++ = t3[2] + t4[2]; + *pMid1++ = t3[3] + t4[3]; /* col 1 */ + + t4[0] = t4[0] - t3[0]; + t4[1] = t4[1] - t3[1]; + t4[2] = t4[2] - t3[2]; + t4[3] = t4[3] - t3[3]; /* for col 2 */ + + twR = *tw++; + twI = *tw++; + + /* multiply by twiddle factors */ + m0 = t2[0] * twR; + m1 = t2[1] * twI; + m2 = t2[1] * twR; + m3 = t2[0] * twI; + + /* R = R * Tr - I * Ti */ + *p2++ = m0 + m1; + /* I = I * Tr + R * Ti */ + *p2++ = m2 - m3; + + /* use vertical symmetry */ + /* 0.9988 - 0.0491i <==> -0.0491 - 0.9988i */ + m0 = t4[0] * twI; + m1 = t4[1] * twR; + m2 = t4[1] * twI; + m3 = t4[0] * twR; + + *pMid2++ = m0 - m1; + *pMid2++ = m2 + m3; + + twR = *tw++; + twI = *tw++; + + m0 = t2[2] * twR; + m1 = t2[3] * twI; + m2 = t2[3] * twR; + m3 = t2[2] * twI; + + *p2++ = m0 + m1; + *p2++ = m2 - m3; + + m0 = t4[2] * twI; + m1 = t4[3] * twR; + m2 = t4[3] * twI; + m3 = t4[2] * twR; + + *pMid2++ = m0 - m1; + *pMid2++ = m2 + m3; + } + + /* first col */ + arm_radix8_butterfly_f32 (pCol1, L, (float32_t *) S->pTwiddle, 2U); + + /* second col */ + arm_radix8_butterfly_f32 (pCol2, L, (float32_t *) S->pTwiddle, 2U); +} + +void arm_cfft_radix8by4_f32 (arm_cfft_instance_f32 * S, float32_t * p1) +{ + uint32_t L = S->fftLen >> 1; + float32_t * pCol1, *pCol2, *pCol3, *pCol4, *pEnd1, *pEnd2, *pEnd3, *pEnd4; + const float32_t *tw2, *tw3, *tw4; + float32_t * p2 = p1 + L; + float32_t * p3 = p2 + L; + float32_t * p4 = p3 + L; + float32_t t2[4], t3[4], t4[4], twR, twI; + float32_t p1ap3_0, p1sp3_0, p1ap3_1, p1sp3_1; + float32_t m0, m1, m2, m3; + uint32_t l, twMod2, twMod3, twMod4; + + pCol1 = p1; /* points to real values by default */ + pCol2 = p2; + pCol3 = p3; + pCol4 = p4; + pEnd1 = p2 - 1; /* points to imaginary values by default */ + pEnd2 = p3 - 1; + pEnd3 = p4 - 1; + pEnd4 = pEnd3 + L; + + tw2 = tw3 = tw4 = (float32_t *) S->pTwiddle; + + L >>= 1; + + /* do four dot Fourier transform */ + + twMod2 = 2; + twMod3 = 4; + twMod4 = 6; + + /* TOP */ + p1ap3_0 = p1[0] + p3[0]; + p1sp3_0 = p1[0] - p3[0]; + p1ap3_1 = p1[1] + p3[1]; + p1sp3_1 = p1[1] - p3[1]; + + /* col 2 */ + t2[0] = p1sp3_0 + p2[1] - p4[1]; + t2[1] = p1sp3_1 - p2[0] + p4[0]; + /* col 3 */ + t3[0] = p1ap3_0 - p2[0] - p4[0]; + t3[1] = p1ap3_1 - p2[1] - p4[1]; + /* col 4 */ + t4[0] = p1sp3_0 - p2[1] + p4[1]; + t4[1] = p1sp3_1 + p2[0] - p4[0]; + /* col 1 */ + *p1++ = p1ap3_0 + p2[0] + p4[0]; + *p1++ = p1ap3_1 + p2[1] + p4[1]; + + /* Twiddle factors are ones */ + *p2++ = t2[0]; + *p2++ = t2[1]; + *p3++ = t3[0]; + *p3++ = t3[1]; + *p4++ = t4[0]; + *p4++ = t4[1]; + + tw2 += twMod2; + tw3 += twMod3; + tw4 += twMod4; + + for (l = (L - 2) >> 1; l > 0; l-- ) + { + /* TOP */ + p1ap3_0 = p1[0] + p3[0]; + p1sp3_0 = p1[0] - p3[0]; + p1ap3_1 = p1[1] + p3[1]; + p1sp3_1 = p1[1] - p3[1]; + /* col 2 */ + t2[0] = p1sp3_0 + p2[1] - p4[1]; + t2[1] = p1sp3_1 - p2[0] + p4[0]; + /* col 3 */ + t3[0] = p1ap3_0 - p2[0] - p4[0]; + t3[1] = p1ap3_1 - p2[1] - p4[1]; + /* col 4 */ + t4[0] = p1sp3_0 - p2[1] + p4[1]; + t4[1] = p1sp3_1 + p2[0] - p4[0]; + /* col 1 - top */ + *p1++ = p1ap3_0 + p2[0] + p4[0]; + *p1++ = p1ap3_1 + p2[1] + p4[1]; + + /* BOTTOM */ + p1ap3_1 = pEnd1[-1] + pEnd3[-1]; + p1sp3_1 = pEnd1[-1] - pEnd3[-1]; + p1ap3_0 = pEnd1[ 0] + pEnd3[0]; + p1sp3_0 = pEnd1[ 0] - pEnd3[0]; + /* col 2 */ + t2[2] = pEnd2[0] - pEnd4[0] + p1sp3_1; + t2[3] = pEnd1[0] - pEnd3[0] - pEnd2[-1] + pEnd4[-1]; + /* col 3 */ + t3[2] = p1ap3_1 - pEnd2[-1] - pEnd4[-1]; + t3[3] = p1ap3_0 - pEnd2[ 0] - pEnd4[ 0]; + /* col 4 */ + t4[2] = pEnd2[ 0] - pEnd4[ 0] - p1sp3_1; + t4[3] = pEnd4[-1] - pEnd2[-1] - p1sp3_0; + /* col 1 - Bottom */ + *pEnd1-- = p1ap3_0 + pEnd2[ 0] + pEnd4[ 0]; + *pEnd1-- = p1ap3_1 + pEnd2[-1] + pEnd4[-1]; + + /* COL 2 */ + /* read twiddle factors */ + twR = *tw2++; + twI = *tw2++; + /* multiply by twiddle factors */ + /* let Z1 = a + i(b), Z2 = c + i(d) */ + /* => Z1 * Z2 = (a*c - b*d) + i(b*c + a*d) */ + + /* Top */ + m0 = t2[0] * twR; + m1 = t2[1] * twI; + m2 = t2[1] * twR; + m3 = t2[0] * twI; + + *p2++ = m0 + m1; + *p2++ = m2 - m3; + /* use vertical symmetry col 2 */ + /* 0.9997 - 0.0245i <==> 0.0245 - 0.9997i */ + /* Bottom */ + m0 = t2[3] * twI; + m1 = t2[2] * twR; + m2 = t2[2] * twI; + m3 = t2[3] * twR; + + *pEnd2-- = m0 - m1; + *pEnd2-- = m2 + m3; + + /* COL 3 */ + twR = tw3[0]; + twI = tw3[1]; + tw3 += twMod3; + /* Top */ + m0 = t3[0] * twR; + m1 = t3[1] * twI; + m2 = t3[1] * twR; + m3 = t3[0] * twI; + + *p3++ = m0 + m1; + *p3++ = m2 - m3; + /* use vertical symmetry col 3 */ + /* 0.9988 - 0.0491i <==> -0.9988 - 0.0491i */ + /* Bottom */ + m0 = -t3[3] * twR; + m1 = t3[2] * twI; + m2 = t3[2] * twR; + m3 = t3[3] * twI; + + *pEnd3-- = m0 - m1; + *pEnd3-- = m3 - m2; + + /* COL 4 */ + twR = tw4[0]; + twI = tw4[1]; + tw4 += twMod4; + /* Top */ + m0 = t4[0] * twR; + m1 = t4[1] * twI; + m2 = t4[1] * twR; + m3 = t4[0] * twI; + + *p4++ = m0 + m1; + *p4++ = m2 - m3; + /* use vertical symmetry col 4 */ + /* 0.9973 - 0.0736i <==> -0.0736 + 0.9973i */ + /* Bottom */ + m0 = t4[3] * twI; + m1 = t4[2] * twR; + m2 = t4[2] * twI; + m3 = t4[3] * twR; + + *pEnd4-- = m0 - m1; + *pEnd4-- = m2 + m3; + } + + /* MIDDLE */ + /* Twiddle factors are */ + /* 1.0000 0.7071-0.7071i -1.0000i -0.7071-0.7071i */ + p1ap3_0 = p1[0] + p3[0]; + p1sp3_0 = p1[0] - p3[0]; + p1ap3_1 = p1[1] + p3[1]; + p1sp3_1 = p1[1] - p3[1]; + + /* col 2 */ + t2[0] = p1sp3_0 + p2[1] - p4[1]; + t2[1] = p1sp3_1 - p2[0] + p4[0]; + /* col 3 */ + t3[0] = p1ap3_0 - p2[0] - p4[0]; + t3[1] = p1ap3_1 - p2[1] - p4[1]; + /* col 4 */ + t4[0] = p1sp3_0 - p2[1] + p4[1]; + t4[1] = p1sp3_1 + p2[0] - p4[0]; + /* col 1 - Top */ + *p1++ = p1ap3_0 + p2[0] + p4[0]; + *p1++ = p1ap3_1 + p2[1] + p4[1]; + + /* COL 2 */ + twR = tw2[0]; + twI = tw2[1]; + + m0 = t2[0] * twR; + m1 = t2[1] * twI; + m2 = t2[1] * twR; + m3 = t2[0] * twI; + + *p2++ = m0 + m1; + *p2++ = m2 - m3; + /* COL 3 */ + twR = tw3[0]; + twI = tw3[1]; + + m0 = t3[0] * twR; + m1 = t3[1] * twI; + m2 = t3[1] * twR; + m3 = t3[0] * twI; + + *p3++ = m0 + m1; + *p3++ = m2 - m3; + /* COL 4 */ + twR = tw4[0]; + twI = tw4[1]; + + m0 = t4[0] * twR; + m1 = t4[1] * twI; + m2 = t4[1] * twR; + m3 = t4[0] * twI; + + *p4++ = m0 + m1; + *p4++ = m2 - m3; + + /* first col */ + arm_radix8_butterfly_f32 (pCol1, L, (float32_t *) S->pTwiddle, 4U); + + /* second col */ + arm_radix8_butterfly_f32 (pCol2, L, (float32_t *) S->pTwiddle, 4U); + + /* third col */ + arm_radix8_butterfly_f32 (pCol3, L, (float32_t *) S->pTwiddle, 4U); + + /* fourth col */ + arm_radix8_butterfly_f32 (pCol4, L, (float32_t *) S->pTwiddle, 4U); +} + +/** + @addtogroup ComplexFFT + @{ + */ + +/** + @brief Processing function for the floating-point complex FFT. + @param[in] S points to an instance of the floating-point CFFT structure + @param[in,out] p1 points to the complex data buffer of size 2*fftLen. Processing occurs in-place + @param[in] ifftFlag flag that selects transform direction + - value = 0: forward transform + - value = 1: inverse transform + @param[in] bitReverseFlag flag that enables / disables bit reversal of output + - value = 0: disables bit reversal of output + - value = 1: enables bit reversal of output + @return none + */ + +void arm_cfft_f32( + const arm_cfft_instance_f32 * S, + float32_t * p1, + uint8_t ifftFlag, + uint8_t bitReverseFlag) +{ + uint32_t L = S->fftLen, l; + float32_t invL, * pSrc; + + if (ifftFlag == 1U) + { + /* Conjugate input data */ + pSrc = p1 + 1; + for (l = 0; l < L; l++) + { + *pSrc = -*pSrc; + pSrc += 2; + } + } + + switch (L) + { + case 16: + case 128: + case 1024: + arm_cfft_radix8by2_f32 ( (arm_cfft_instance_f32 *) S, p1); + break; + case 32: + case 256: + case 2048: + arm_cfft_radix8by4_f32 ( (arm_cfft_instance_f32 *) S, p1); + break; + case 64: + case 512: + case 4096: + arm_radix8_butterfly_f32 ( p1, L, (float32_t *) S->pTwiddle, 1); + break; + } + + if ( bitReverseFlag ) + arm_bitreversal_32 ((uint32_t*) p1, S->bitRevLength, S->pBitRevTable); + + if (ifftFlag == 1U) + { + invL = 1.0f / (float32_t)L; + + /* Conjugate and scale output data */ + pSrc = p1; + for (l= 0; l < L; l++) + { + *pSrc++ *= invL ; + *pSrc = -(*pSrc) * invL; + pSrc++; + } + } +} + +/** + @} end of ComplexFFT group + */ -- cgit v1.2.3