Michele Riccio
mbed-os 6.10 versione
Diff: cmsis_dsp/TransformFunctions/arm_cfft_radix4_f32.c
- Revision:
- 3:7a284390b0ce
- Parent:
- 2:da51fb522205
diff -r da51fb522205 -r 7a284390b0ce cmsis_dsp/TransformFunctions/arm_cfft_radix4_f32.c
--- a/cmsis_dsp/TransformFunctions/arm_cfft_radix4_f32.c Thu May 30 17:10:11 2013 +0100
+++ b/cmsis_dsp/TransformFunctions/arm_cfft_radix4_f32.c Fri Nov 08 13:45:10 2013 +0000
@@ -1,8 +1,8 @@
/* ----------------------------------------------------------------------
-* Copyright (C) 2010 ARM Limited. All rights reserved.
+* Copyright (C) 2010-2013 ARM Limited. All rights reserved.
*
-* $Date: 15. February 2012
-* $Revision: V1.1.0
+* $Date: 17. January 2013
+* $Revision: V1.4.1
*
* Project: CMSIS DSP Library
* Title: arm_cfft_radix4_f32.c
@@ -12,1225 +12,1199 @@
*
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
*
-* Version 1.1.0 2012/02/15
-* Updated with more optimizations, bug fixes and minor API changes.
-*
-* Version 1.0.10 2011/7/15
-* Big Endian support added and Merged M0 and M3/M4 Source code.
-*
-* Version 1.0.3 2010/11/29
-* Re-organized the CMSIS folders and updated documentation.
-*
-* Version 1.0.2 2010/11/11
-* Documentation updated.
-*
-* Version 1.0.1 2010/10/05
-* Production release and review comments incorporated.
-*
-* Version 1.0.0 2010/09/20
-* Production release and review comments incorporated.
-*
-* Version 0.0.5 2010/04/26
-* incorporated review comments and updated with latest CMSIS layer
-*
-* Version 0.0.3 2010/03/10
-* Initial version
+* Redistribution and use in source and binary forms, with or without
+* modification, are permitted provided that the following conditions
+* are met:
+* - Redistributions of source code must retain the above copyright
+* notice, this list of conditions and the following disclaimer.
+* - Redistributions in binary form must reproduce the above copyright
+* notice, this list of conditions and the following disclaimer in
+* the documentation and/or other materials provided with the
+* distribution.
+* - Neither the name of ARM LIMITED nor the names of its contributors
+* may be used to endorse or promote products derived from this
+* software without specific prior written permission.
+*
+* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+* POSSIBILITY OF SUCH DAMAGE.
* -------------------------------------------------------------------- */
#include "arm_math.h"
-/**
- * @ingroup groupTransforms
- */
+extern void arm_bitreversal_f32(
+float32_t * pSrc,
+uint16_t fftSize,
+uint16_t bitRevFactor,
+uint16_t * pBitRevTab);
/**
- * @defgroup Radix4_CFFT_CIFFT Radix-4 Complex FFT Functions
- *
- * \par
- * Complex Fast Fourier Transform(CFFT) and Complex Inverse Fast Fourier Transform(CIFFT) is an efficient algorithm to compute Discrete Fourier Transform(DFT) and Inverse Discrete Fourier Transform(IDFT).
- * Computational complexity of CFFT reduces drastically when compared to DFT.
- * \par
- * This set of functions implements CFFT/CIFFT
- * for Q15, Q31, and floating-point data types. The functions operates on in-place buffer which uses same buffer for input and output.
- * Complex input is stored in input buffer in an interleaved fashion.
- *
- * \par
- * The functions operate on blocks of input and output data and each call to the function processes
- * <code>2*fftLen</code> samples through the transform. <code>pSrc</code> points to In-place arrays containing <code>2*fftLen</code> values.
- * \par
- * The <code>pSrc</code> points to the array of in-place buffer of size <code>2*fftLen</code> and inputs and outputs are stored in an interleaved fashion as shown below.
- * <pre> {real[0], imag[0], real[1], imag[1],..} </pre>
- *
- * \par Lengths supported by the transform:
- * \par
- * Internally, the function utilize a radix-4 decimation in frequency(DIF) algorithm
- * and the size of the FFT supported are of the lengths [16, 64, 256, 1024].
- *
- *
- * \par Algorithm:
- *
- * <b>Complex Fast Fourier Transform:</b>
- * \par
- * Input real and imaginary data:
- * <pre>
- * x(n) = xa + j * ya
- * x(n+N/4 ) = xb + j * yb
- * x(n+N/2 ) = xc + j * yc
- * x(n+3N 4) = xd + j * yd
- * </pre>
- * where N is length of FFT
- * \par
- * Output real and imaginary data:
- * <pre>
- * X(4r) = xa'+ j * ya'
- * X(4r+1) = xb'+ j * yb'
- * X(4r+2) = xc'+ j * yc'
- * X(4r+3) = xd'+ j * yd'
- * </pre>
- * \par
- * Twiddle factors for radix-4 FFT:
- * <pre>
- * Wn = co1 + j * (- si1)
- * W2n = co2 + j * (- si2)
- * W3n = co3 + j * (- si3)
- * </pre>
- *
- * \par
- * \image html CFFT.gif "Radix-4 Decimation-in Frequency Complex Fast Fourier Transform"
- *
- * \par
- * Output from Radix-4 CFFT Results in Digit reversal order. Interchange middle two branches of every butterfly results in Bit reversed output.
- * \par
- * <b> Butterfly CFFT equations:</b>
- * <pre>
- * xa' = xa + xb + xc + xd
- * ya' = ya + yb + yc + yd
- * xc' = (xa+yb-xc-yd)* co1 + (ya-xb-yc+xd)* (si1)
- * yc' = (ya-xb-yc+xd)* co1 - (xa+yb-xc-yd)* (si1)
- * xb' = (xa-xb+xc-xd)* co2 + (ya-yb+yc-yd)* (si2)
- * yb' = (ya-yb+yc-yd)* co2 - (xa-xb+xc-xd)* (si2)
- * xd' = (xa-yb-xc+yd)* co3 + (ya+xb-yc-xd)* (si3)
- * yd' = (ya+xb-yc-xd)* co3 - (xa-yb-xc+yd)* (si3)
- * </pre>
- *
- *
- * <b>Complex Inverse Fast Fourier Transform:</b>
- * \par
- * CIFFT uses same twiddle factor table as CFFT with modifications in the design equation as shown below.
- *
- * \par
- * <b> Modified Butterfly CIFFT equations:</b>
- * <pre>
- * xa' = xa + xb + xc + xd
- * ya' = ya + yb + yc + yd
- * xc' = (xa-yb-xc+yd)* co1 - (ya+xb-yc-xd)* (si1)
- * yc' = (ya+xb-yc-xd)* co1 + (xa-yb-xc+yd)* (si1)
- * xb' = (xa-xb+xc-xd)* co2 - (ya-yb+yc-yd)* (si2)
- * yb' = (ya-yb+yc-yd)* co2 + (xa-xb+xc-xd)* (si2)
- * xd' = (xa+yb-xc-yd)* co3 - (ya-xb-yc+xd)* (si3)
- * yd' = (ya-xb-yc+xd)* co3 + (xa+yb-xc-yd)* (si3)
- * </pre>
- *
- * \par Instance Structure
- * A separate instance structure must be defined for each Instance but the twiddle factors and bit reversal tables can be reused.
- * There are separate instance structure declarations for each of the 3 supported data types.
- *
- * \par Initialization Functions
- * There is also an associated initialization function for each data type.
- * The initialization function performs the following operations:
- * - Sets the values of the internal structure fields.
- * - Initializes twiddle factor table and bit reversal table pointers
- * \par
- * Use of the initialization function is optional.
- * However, if the initialization function is used, then the instance structure cannot be placed into a const data section.
- * To place an instance structure into a const data section, the instance structure must be manually initialized.
- * Manually initialize the instance structure as follows:
- * <pre>
- *arm_cfft_radix4_instance_f32 S = {fftLen, ifftFlag, bitReverseFlag, pTwiddle, pBitRevTable, twidCoefModifier, bitRevFactor, onebyfftLen};
- *arm_cfft_radix4_instance_q31 S = {fftLen, ifftFlag, bitReverseFlag, pTwiddle, pBitRevTable, twidCoefModifier, bitRevFactor};
- *arm_cfft_radix4_instance_q15 S = {fftLen, ifftFlag, bitReverseFlag, pTwiddle, pBitRevTable, twidCoefModifier, bitRevFactor};
- * </pre>
- * \par
- * where <code>fftLen</code> length of CFFT/CIFFT; <code>ifftFlag</code> Flag for selection of CFFT or CIFFT(Set ifftFlag to calculate CIFFT otherwise calculates CFFT);
- * <code>bitReverseFlag</code> Flag for selection of output order(Set bitReverseFlag to output in normal order otherwise output in bit reversed order);
- * <code>pTwiddle</code>points to array of twiddle coefficients; <code>pBitRevTable</code> points to the array of bit reversal table.
- * <code>twidCoefModifier</code> modifier for twiddle factor table which supports all FFT lengths with same table;
- * <code>pBitRevTable</code> modifier for bit reversal table which supports all FFT lengths with same table.
- * <code>onebyfftLen</code> value of 1/fftLen to calculate CIFFT;
- *
- * \par Fixed-Point Behavior
- * Care must be taken when using the fixed-point versions of the CFFT/CIFFT function.
- * Refer to the function specific documentation below for usage guidelines.
- */
-
-
-/**
- * @addtogroup Radix4_CFFT_CIFFT
- * @{
- */
-
-/**
- * @details
- * @brief Processing function for the floating-point Radix-4 CFFT/CIFFT.
- * @param[in] *S points to an instance of the floating-point Radix-4 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_radix4_f32(
- const arm_cfft_radix4_instance_f32 * S,
- float32_t * pSrc)
-{
-
- if(S->ifftFlag == 1u)
- {
- /* Complex IFFT radix-4 */
- arm_radix4_butterfly_inverse_f32(pSrc, S->fftLen, S->pTwiddle,
- S->twidCoefModifier, S->onebyfftLen);
- }
- else
- {
- /* Complex FFT radix-4 */
- arm_radix4_butterfly_f32(pSrc, S->fftLen, S->pTwiddle,
- S->twidCoefModifier);
- }
-
- if(S->bitReverseFlag == 1u)
- {
- /* Bit Reversal */
- arm_bitreversal_f32(pSrc, S->fftLen, S->bitRevFactor, S->pBitRevTable);
- }
-
-}
-
-
-/**
- * @} end of Radix4_CFFT_CIFFT group
- */
-
+* @ingroup groupTransforms
+*/
/* ----------------------------------------------------------------------
** Internal helper function used by the FFTs
** ------------------------------------------------------------------- */
/*
- * @brief Core function for the floating-point CFFT butterfly process.
- * @param[in, out] *pSrc points to the in-place buffer of floating-point data type.
- * @param[in] fftLen length of the FFT.
- * @param[in] *pCoef points to the twiddle coefficient buffer.
- * @param[in] twidCoefModifier twiddle coefficient modifier that supports different size FFTs with the same twiddle factor table.
- * @return none.
- */
+* @brief Core function for the floating-point CFFT butterfly process.
+* @param[in, out] *pSrc points to the in-place buffer of floating-point data type.
+* @param[in] fftLen length of the FFT.
+* @param[in] *pCoef points to the twiddle coefficient buffer.
+* @param[in] twidCoefModifier twiddle coefficient modifier that supports different size FFTs with the same twiddle factor table.
+* @return none.
+*/
void arm_radix4_butterfly_f32(
- float32_t * pSrc,
- uint16_t fftLen,
- float32_t * pCoef,
- uint16_t twidCoefModifier)
+float32_t * pSrc,
+uint16_t fftLen,
+float32_t * pCoef,
+uint16_t twidCoefModifier)
{
- float32_t co1, co2, co3, si1, si2, si3;
- uint32_t ia1, ia2, ia3;
- uint32_t i0, i1, i2, i3;
- uint32_t n1, n2, j, k;
-
-#ifndef ARM_MATH_CM0
-
- /* Run the below code for Cortex-M4 and Cortex-M3 */
-
- float32_t xaIn, yaIn, xbIn, ybIn, xcIn, ycIn, xdIn, ydIn;
- float32_t Xaplusc, Xbplusd, Yaplusc, Ybplusd, Xaminusc, Xbminusd, Yaminusc,
- Ybminusd;
- float32_t Xb12C_out, Yb12C_out, Xc12C_out, Yc12C_out, Xd12C_out, Yd12C_out;
- float32_t Xb12_out, Yb12_out, Xc12_out, Yc12_out, Xd12_out, Yd12_out;
- float32_t *ptr1;
+ float32_t co1, co2, co3, si1, si2, si3;
+ uint32_t ia1, ia2, ia3;
+ uint32_t i0, i1, i2, i3;
+ uint32_t n1, n2, j, k;
- /* Initializations for the first stage */
- n2 = fftLen;
- n1 = n2;
-
- /* n2 = fftLen/4 */
- n2 >>= 2u;
- i0 = 0u;
- ia1 = 0u;
+#ifndef ARM_MATH_CM0_FAMILY_FAMILY
- j = n2;
-
- /* Calculation of first stage */
- do
- {
- /* index calculation for the input as, */
- /* pSrc[i0 + 0], pSrc[i0 + fftLen/4], pSrc[i0 + fftLen/2], pSrc[i0 + 3fftLen/4] */
- i1 = i0 + n2;
- i2 = i1 + n2;
- i3 = i2 + n2;
+ /* Run the below code for Cortex-M4 and Cortex-M3 */
- xaIn = pSrc[(2u * i0)];
- yaIn = pSrc[(2u * i0) + 1u];
-
- xcIn = pSrc[(2u * i2)];
- ycIn = pSrc[(2u * i2) + 1u];
-
- xbIn = pSrc[(2u * i1)];
- ybIn = pSrc[(2u * i1) + 1u];
-
- xdIn = pSrc[(2u * i3)];
- ydIn = pSrc[(2u * i3) + 1u];
+ float32_t xaIn, yaIn, xbIn, ybIn, xcIn, ycIn, xdIn, ydIn;
+ float32_t Xaplusc, Xbplusd, Yaplusc, Ybplusd, Xaminusc, Xbminusd, Yaminusc,
+ Ybminusd;
+ float32_t Xb12C_out, Yb12C_out, Xc12C_out, Yc12C_out, Xd12C_out, Yd12C_out;
+ float32_t Xb12_out, Yb12_out, Xc12_out, Yc12_out, Xd12_out, Yd12_out;
+ float32_t *ptr1;
+ float32_t p0,p1,p2,p3,p4,p5;
+ float32_t a0,a1,a2,a3,a4,a5,a6,a7;
- /* xa + xc */
- Xaplusc = xaIn + xcIn;
- /* xb + xd */
- Xbplusd = xbIn + xdIn;
- /* ya + yc */
- Yaplusc = yaIn + ycIn;
- /* yb + yd */
- Ybplusd = ybIn + ydIn;
-
- /* index calculation for the coefficients */
- ia2 = ia1 + ia1;
- co2 = pCoef[ia2 * 2u];
- si2 = pCoef[(ia2 * 2u) + 1u];
+ /* Initializations for the first stage */
+ n2 = fftLen;
+ n1 = n2;
- /* xa - xc */
- Xaminusc = xaIn - xcIn;
- /* xb - xd */
- Xbminusd = xbIn - xdIn;
- /* ya - yc */
- Yaminusc = yaIn - ycIn;
- /* yb + yd */
- Ybminusd = ybIn - ydIn;
+ /* n2 = fftLen/4 */
+ n2 >>= 2u;
+ i0 = 0u;
+ ia1 = 0u;
- /* xa' = xa + xb + xc + xd */
- pSrc[(2u * i0)] = Xaplusc + Xbplusd;
- /* ya' = ya + yb + yc + yd */
- pSrc[(2u * i0) + 1u] = Yaplusc + Ybplusd;
+ j = n2;
- /* (xa - xc) + (yb - yd) */
- Xb12C_out = (Xaminusc + Ybminusd);
- /* (ya - yc) + (xb - xd) */
- Yb12C_out = (Yaminusc - Xbminusd);
- /* (xa + xc) - (xb + xd) */
- Xc12C_out = (Xaplusc - Xbplusd);
- /* (ya + yc) - (yb + yd) */
- Yc12C_out = (Yaplusc - Ybplusd);
- /* (xa - xc) - (yb - yd) */
- Xd12C_out = (Xaminusc - Ybminusd);
- /* (ya - yc) + (xb - xd) */
- Yd12C_out = (Xbminusd + Yaminusc);
-
- co1 = pCoef[ia1 * 2u];
- si1 = pCoef[(ia1 * 2u) + 1u];
+ /* Calculation of first stage */
+ do
+ {
+ /* index calculation for the input as, */
+ /* pSrc[i0 + 0], pSrc[i0 + fftLen/4], pSrc[i0 + fftLen/2], pSrc[i0 + 3fftLen/4] */
+ i1 = i0 + n2;
+ i2 = i1 + n2;
+ i3 = i2 + n2;
- /* index calculation for the coefficients */
- ia3 = ia2 + ia1;
- co3 = pCoef[ia3 * 2u];
- si3 = pCoef[(ia3 * 2u) + 1u];
-
- Xb12_out = Xb12C_out * co1;
- Yb12_out = Yb12C_out * co1;
- Xc12_out = Xc12C_out * co2;
- Yc12_out = Yc12C_out * co2;
- Xd12_out = Xd12C_out * co3;
- Yd12_out = Yd12C_out * co3;
+ xaIn = pSrc[(2u * i0)];
+ yaIn = pSrc[(2u * i0) + 1u];
- /* xb' = (xa+yb-xc-yd)co1 + (ya-xb-yc+xd)(si1) */
- Xb12_out += Yb12C_out * si1;
- /* yb' = (ya-xb-yc+xd)co1 - (xa+yb-xc-yd)(si1) */
- Yb12_out -= Xb12C_out * si1;
- /* xc' = (xa-xb+xc-xd)co2 + (ya-yb+yc-yd)(si2) */
- Xc12_out += Yc12C_out * si2;
- /* yc' = (ya-yb+yc-yd)co2 - (xa-xb+xc-xd)(si2) */
- Yc12_out -= Xc12C_out * si2;
- /* xd' = (xa-yb-xc+yd)co3 + (ya+xb-yc-xd)(si3) */
- Xd12_out += Yd12C_out * si3;
- /* yd' = (ya+xb-yc-xd)co3 - (xa-yb-xc+yd)(si3) */
- Yd12_out -= Xd12C_out * si3;
+ xbIn = pSrc[(2u * i1)];
+ ybIn = pSrc[(2u * i1) + 1u];
-
- /* xc' = (xa-xb+xc-xd)co2 + (ya-yb+yc-yd)(si2) */
- pSrc[2u * i1] = Xc12_out;
-
- /* yc' = (ya-yb+yc-yd)co2 - (xa-xb+xc-xd)(si2) */
- pSrc[(2u * i1) + 1u] = Yc12_out;
+ xcIn = pSrc[(2u * i2)];
+ ycIn = pSrc[(2u * i2) + 1u];
- /* xb' = (xa+yb-xc-yd)co1 + (ya-xb-yc+xd)(si1) */
- pSrc[2u * i2] = Xb12_out;
-
- /* yb' = (ya-xb-yc+xd)co1 - (xa+yb-xc-yd)(si1) */
- pSrc[(2u * i2) + 1u] = Yb12_out;
-
- /* xd' = (xa-yb-xc+yd)co3 + (ya+xb-yc-xd)(si3) */
- pSrc[2u * i3] = Xd12_out;
-
- /* yd' = (ya+xb-yc-xd)co3 - (xa-yb-xc+yd)(si3) */
- pSrc[(2u * i3) + 1u] = Yd12_out;
+ xdIn = pSrc[(2u * i3)];
+ ydIn = pSrc[(2u * i3) + 1u];
- /* Twiddle coefficients index modifier */
- ia1 = ia1 + twidCoefModifier;
-
- /* Updating input index */
- i0 = i0 + 1u;
-
- }
- while(--j);
-
- twidCoefModifier <<= 2u;
+ /* xa + xc */
+ Xaplusc = xaIn + xcIn;
+ /* xb + xd */
+ Xbplusd = xbIn + xdIn;
+ /* ya + yc */
+ Yaplusc = yaIn + ycIn;
+ /* yb + yd */
+ Ybplusd = ybIn + ydIn;
- /* Calculation of second stage to excluding last stage */
- for (k = fftLen / 4; k > 4u; k >>= 2u)
- {
- /* Initializations for the first stage */
- n1 = n2;
- n2 >>= 2u;
- ia1 = 0u;
-
- /* Calculation of first stage */
- for (j = 0u; j <= (n2 - 1u); j++)
- {
/* index calculation for the coefficients */
ia2 = ia1 + ia1;
- ia3 = ia2 + ia1;
+ co2 = pCoef[ia2 * 2u];
+ si2 = pCoef[(ia2 * 2u) + 1u];
+
+ /* xa - xc */
+ Xaminusc = xaIn - xcIn;
+ /* xb - xd */
+ Xbminusd = xbIn - xdIn;
+ /* ya - yc */
+ Yaminusc = yaIn - ycIn;
+ /* yb - yd */
+ Ybminusd = ybIn - ydIn;
+
+ /* xa' = xa + xb + xc + xd */
+ pSrc[(2u * i0)] = Xaplusc + Xbplusd;
+ /* ya' = ya + yb + yc + yd */
+ pSrc[(2u * i0) + 1u] = Yaplusc + Ybplusd;
+
+ /* (xa - xc) + (yb - yd) */
+ Xb12C_out = (Xaminusc + Ybminusd);
+ /* (ya - yc) + (xb - xd) */
+ Yb12C_out = (Yaminusc - Xbminusd);
+ /* (xa + xc) - (xb + xd) */
+ Xc12C_out = (Xaplusc - Xbplusd);
+ /* (ya + yc) - (yb + yd) */
+ Yc12C_out = (Yaplusc - Ybplusd);
+ /* (xa - xc) - (yb - yd) */
+ Xd12C_out = (Xaminusc - Ybminusd);
+ /* (ya - yc) + (xb - xd) */
+ Yd12C_out = (Xbminusd + Yaminusc);
+
co1 = pCoef[ia1 * 2u];
si1 = pCoef[(ia1 * 2u) + 1u];
- co2 = pCoef[ia2 * 2u];
- si2 = pCoef[(ia2 * 2u) + 1u];
+
+ /* index calculation for the coefficients */
+ ia3 = ia2 + ia1;
co3 = pCoef[ia3 * 2u];
si3 = pCoef[(ia3 * 2u) + 1u];
- /* Twiddle coefficients index modifier */
- ia1 = ia1 + twidCoefModifier;
-
- for (i0 = j; i0 < fftLen; i0 += n1)
- {
- /* index calculation for the input as, */
- /* pSrc[i0 + 0], pSrc[i0 + fftLen/4], pSrc[i0 + fftLen/2], pSrc[i0 + 3fftLen/4] */
- i1 = i0 + n2;
- i2 = i1 + n2;
- i3 = i2 + n2;
-
- xaIn = pSrc[(2u * i0)];
- yaIn = pSrc[(2u * i0) + 1u];
-
- xbIn = pSrc[(2u * i1)];
- ybIn = pSrc[(2u * i1) + 1u];
-
- xcIn = pSrc[(2u * i2)];
- ycIn = pSrc[(2u * i2) + 1u];
+ Xb12_out = Xb12C_out * co1;
+ Yb12_out = Yb12C_out * co1;
+ Xc12_out = Xc12C_out * co2;
+ Yc12_out = Yc12C_out * co2;
+ Xd12_out = Xd12C_out * co3;
+ Yd12_out = Yd12C_out * co3;
+
+ /* xb' = (xa+yb-xc-yd)co1 - (ya-xb-yc+xd)(si1) */
+ //Xb12_out -= Yb12C_out * si1;
+ p0 = Yb12C_out * si1;
+ /* yb' = (ya-xb-yc+xd)co1 + (xa+yb-xc-yd)(si1) */
+ //Yb12_out += Xb12C_out * si1;
+ p1 = Xb12C_out * si1;
+ /* xc' = (xa-xb+xc-xd)co2 - (ya-yb+yc-yd)(si2) */
+ //Xc12_out -= Yc12C_out * si2;
+ p2 = Yc12C_out * si2;
+ /* yc' = (ya-yb+yc-yd)co2 + (xa-xb+xc-xd)(si2) */
+ //Yc12_out += Xc12C_out * si2;
+ p3 = Xc12C_out * si2;
+ /* xd' = (xa-yb-xc+yd)co3 - (ya+xb-yc-xd)(si3) */
+ //Xd12_out -= Yd12C_out * si3;
+ p4 = Yd12C_out * si3;
+ /* yd' = (ya+xb-yc-xd)co3 + (xa-yb-xc+yd)(si3) */
+ //Yd12_out += Xd12C_out * si3;
+ p5 = Xd12C_out * si3;
+
+ Xb12_out += p0;
+ Yb12_out -= p1;
+ Xc12_out += p2;
+ Yc12_out -= p3;
+ Xd12_out += p4;
+ Yd12_out -= p5;
- xdIn = pSrc[(2u * i3)];
- ydIn = pSrc[(2u * i3) + 1u];
+ /* xc' = (xa-xb+xc-xd)co2 + (ya-yb+yc-yd)(si2) */
+ pSrc[2u * i1] = Xc12_out;
+
+ /* yc' = (ya-yb+yc-yd)co2 - (xa-xb+xc-xd)(si2) */
+ pSrc[(2u * i1) + 1u] = Yc12_out;
+
+ /* xb' = (xa+yb-xc-yd)co1 + (ya-xb-yc+xd)(si1) */
+ pSrc[2u * i2] = Xb12_out;
+
+ /* yb' = (ya-xb-yc+xd)co1 - (xa+yb-xc-yd)(si1) */
+ pSrc[(2u * i2) + 1u] = Yb12_out;
- /* xa - xc */
- Xaminusc = xaIn - xcIn;
- /* (xb - xd) */
- Xbminusd = xbIn - xdIn;
- /* ya - yc */
- Yaminusc = yaIn - ycIn;
- /* (yb - yd) */
- Ybminusd = ybIn - ydIn;
+ /* xd' = (xa-yb-xc+yd)co3 + (ya+xb-yc-xd)(si3) */
+ pSrc[2u * i3] = Xd12_out;
+
+ /* yd' = (ya+xb-yc-xd)co3 - (xa-yb-xc+yd)(si3) */
+ pSrc[(2u * i3) + 1u] = Yd12_out;
- /* xa + xc */
- Xaplusc = xaIn + xcIn;
- /* xb + xd */
- Xbplusd = xbIn + xdIn;
- /* ya + yc */
- Yaplusc = yaIn + ycIn;
- /* yb + yd */
- Ybplusd = ybIn + ydIn;
+ /* Twiddle coefficients index modifier */
+ ia1 += twidCoefModifier;
+
+ /* Updating input index */
+ i0++;
+
+ }
+ while(--j);
+
+ twidCoefModifier <<= 2u;
- /* (xa - xc) + (yb - yd) */
- Xb12C_out = (Xaminusc + Ybminusd);
- /* (ya - yc) - (xb - xd) */
- Yb12C_out = (Yaminusc - Xbminusd);
- /* xa + xc -(xb + xd) */
- Xc12C_out = (Xaplusc - Xbplusd);
- /* (ya + yc) - (yb + yd) */
- Yc12C_out = (Yaplusc - Ybplusd);
- /* (xa - xc) - (yb - yd) */
- Xd12C_out = (Xaminusc - Ybminusd);
- /* (ya - yc) + (xb - xd) */
- Yd12C_out = (Xbminusd + Yaminusc);
+ /* Calculation of second stage to excluding last stage */
+ for (k = fftLen >> 2u; k > 4u; k >>= 2u)
+ {
+ /* Initializations for the first stage */
+ n1 = n2;
+ n2 >>= 2u;
+ ia1 = 0u;
- pSrc[(2u * i0)] = Xaplusc + Xbplusd;
- pSrc[(2u * i0) + 1u] = Yaplusc + Ybplusd;
+ /* Calculation of first stage */
+ j = 0;
+ do
+ {
+ /* index calculation for the coefficients */
+ ia2 = ia1 + ia1;
+ ia3 = ia2 + ia1;
+ co1 = pCoef[ia1 * 2u];
+ si1 = pCoef[(ia1 * 2u) + 1u];
+ co2 = pCoef[ia2 * 2u];
+ si2 = pCoef[(ia2 * 2u) + 1u];
+ co3 = pCoef[ia3 * 2u];
+ si3 = pCoef[(ia3 * 2u) + 1u];
- Xb12_out = Xb12C_out * co1;
- Yb12_out = Yb12C_out * co1;
- Xc12_out = Xc12C_out * co2;
- Yc12_out = Yc12C_out * co2;
- Xd12_out = Xd12C_out * co3;
- Yd12_out = Yd12C_out * co3;
+ /* Twiddle coefficients index modifier */
+ ia1 += twidCoefModifier;
+
+ i0 = j;
+ do
+ {
+ /* index calculation for the input as, */
+ /* pSrc[i0 + 0], pSrc[i0 + fftLen/4], pSrc[i0 + fftLen/2], pSrc[i0 + 3fftLen/4] */
+ i1 = i0 + n2;
+ i2 = i1 + n2;
+ i3 = i2 + n2;
+
+ xaIn = pSrc[(2u * i0)];
+ yaIn = pSrc[(2u * i0) + 1u];
+
+ xbIn = pSrc[(2u * i1)];
+ ybIn = pSrc[(2u * i1) + 1u];
+
+ xcIn = pSrc[(2u * i2)];
+ ycIn = pSrc[(2u * i2) + 1u];
- /* xb' = (xa+yb-xc-yd)co1 + (ya-xb-yc+xd)(si1) */
- Xb12_out += Yb12C_out * si1;
- /* yb' = (ya-xb-yc+xd)co1 - (xa+yb-xc-yd)(si1) */
- Yb12_out -= Xb12C_out * si1;
- /* xc' = (xa-xb+xc-xd)co2 + (ya-yb+yc-yd)(si2) */
- Xc12_out += Yc12C_out * si2;
- /* yc' = (ya-yb+yc-yd)co2 - (xa-xb+xc-xd)(si2) */
- Yc12_out -= Xc12C_out * si2;
- /* xd' = (xa-yb-xc+yd)co3 + (ya+xb-yc-xd)(si3) */
- Xd12_out += Yd12C_out * si3;
- /* yd' = (ya+xb-yc-xd)co3 - (xa-yb-xc+yd)(si3) */
- Yd12_out -= Xd12C_out * si3;
+ xdIn = pSrc[(2u * i3)];
+ ydIn = pSrc[(2u * i3) + 1u];
- /* xc' = (xa-xb+xc-xd)co2 + (ya-yb+yc-yd)(si2) */
- pSrc[2u * i1] = Xc12_out;
+ /* xa - xc */
+ Xaminusc = xaIn - xcIn;
+ /* (xb - xd) */
+ Xbminusd = xbIn - xdIn;
+ /* ya - yc */
+ Yaminusc = yaIn - ycIn;
+ /* (yb - yd) */
+ Ybminusd = ybIn - ydIn;
- /* yc' = (ya-yb+yc-yd)co2 - (xa-xb+xc-xd)(si2) */
- pSrc[(2u * i1) + 1u] = Yc12_out;
+ /* xa + xc */
+ Xaplusc = xaIn + xcIn;
+ /* xb + xd */
+ Xbplusd = xbIn + xdIn;
+ /* ya + yc */
+ Yaplusc = yaIn + ycIn;
+ /* yb + yd */
+ Ybplusd = ybIn + ydIn;
- /* xb' = (xa+yb-xc-yd)co1 + (ya-xb-yc+xd)(si1) */
- pSrc[2u * i2] = Xb12_out;
-
- /* yb' = (ya-xb-yc+xd)co1 - (xa+yb-xc-yd)(si1) */
- pSrc[(2u * i2) + 1u] = Yb12_out;
-
- /* xd' = (xa-yb-xc+yd)co3 + (ya+xb-yc-xd)(si3) */
- pSrc[2u * i3] = Xd12_out;
+ /* (xa - xc) + (yb - yd) */
+ Xb12C_out = (Xaminusc + Ybminusd);
+ /* (ya - yc) - (xb - xd) */
+ Yb12C_out = (Yaminusc - Xbminusd);
+ /* xa + xc -(xb + xd) */
+ Xc12C_out = (Xaplusc - Xbplusd);
+ /* (ya + yc) - (yb + yd) */
+ Yc12C_out = (Yaplusc - Ybplusd);
+ /* (xa - xc) - (yb - yd) */
+ Xd12C_out = (Xaminusc - Ybminusd);
+ /* (ya - yc) + (xb - xd) */
+ Yd12C_out = (Xbminusd + Yaminusc);
- /* yd' = (ya+xb-yc-xd)co3 - (xa-yb-xc+yd)(si3) */
- pSrc[(2u * i3) + 1u] = Yd12_out;
-
- }
- }
- twidCoefModifier <<= 2u;
- }
-
- j = fftLen >> 2;
- ptr1 = &pSrc[0];
+ pSrc[(2u * i0)] = Xaplusc + Xbplusd;
+ pSrc[(2u * i0) + 1u] = Yaplusc + Ybplusd;
- /* Calculations of last stage */
- do
- {
-
- xaIn = ptr1[0];
- xcIn = ptr1[4];
- yaIn = ptr1[1];
- ycIn = ptr1[5];
+ Xb12_out = Xb12C_out * co1;
+ Yb12_out = Yb12C_out * co1;
+ Xc12_out = Xc12C_out * co2;
+ Yc12_out = Yc12C_out * co2;
+ Xd12_out = Xd12C_out * co3;
+ Yd12_out = Yd12C_out * co3;
+
+ /* xb' = (xa+yb-xc-yd)co1 - (ya-xb-yc+xd)(si1) */
+ //Xb12_out -= Yb12C_out * si1;
+ p0 = Yb12C_out * si1;
+ /* yb' = (ya-xb-yc+xd)co1 + (xa+yb-xc-yd)(si1) */
+ //Yb12_out += Xb12C_out * si1;
+ p1 = Xb12C_out * si1;
+ /* xc' = (xa-xb+xc-xd)co2 - (ya-yb+yc-yd)(si2) */
+ //Xc12_out -= Yc12C_out * si2;
+ p2 = Yc12C_out * si2;
+ /* yc' = (ya-yb+yc-yd)co2 + (xa-xb+xc-xd)(si2) */
+ //Yc12_out += Xc12C_out * si2;
+ p3 = Xc12C_out * si2;
+ /* xd' = (xa-yb-xc+yd)co3 - (ya+xb-yc-xd)(si3) */
+ //Xd12_out -= Yd12C_out * si3;
+ p4 = Yd12C_out * si3;
+ /* yd' = (ya+xb-yc-xd)co3 + (xa-yb-xc+yd)(si3) */
+ //Yd12_out += Xd12C_out * si3;
+ p5 = Xd12C_out * si3;
+
+ Xb12_out += p0;
+ Yb12_out -= p1;
+ Xc12_out += p2;
+ Yc12_out -= p3;
+ Xd12_out += p4;
+ Yd12_out -= p5;
- /* xa + xc */
- Xaplusc = xaIn + xcIn;
+ /* xc' = (xa-xb+xc-xd)co2 + (ya-yb+yc-yd)(si2) */
+ pSrc[2u * i1] = Xc12_out;
- xbIn = ptr1[2];
+ /* yc' = (ya-yb+yc-yd)co2 - (xa-xb+xc-xd)(si2) */
+ pSrc[(2u * i1) + 1u] = Yc12_out;
+
+ /* xb' = (xa+yb-xc-yd)co1 + (ya-xb-yc+xd)(si1) */
+ pSrc[2u * i2] = Xb12_out;
- /* xa - xc */
- Xaminusc = xaIn - xcIn;
+ /* yb' = (ya-xb-yc+xd)co1 - (xa+yb-xc-yd)(si1) */
+ pSrc[(2u * i2) + 1u] = Yb12_out;
- xdIn = ptr1[6];
+ /* xd' = (xa-yb-xc+yd)co3 + (ya+xb-yc-xd)(si3) */
+ pSrc[2u * i3] = Xd12_out;
- /* ya + yc */
- Yaplusc = yaIn + ycIn;
+ /* yd' = (ya+xb-yc-xd)co3 - (xa-yb-xc+yd)(si3) */
+ pSrc[(2u * i3) + 1u] = Yd12_out;
- ybIn = ptr1[3];
+ i0 += n1;
+ } while(i0 < fftLen);
+ j++;
+ } while(j <= (n2 - 1u));
+ twidCoefModifier <<= 2u;
+ }
- /* ya - yc */
- Yaminusc = yaIn - ycIn;
-
- ydIn = ptr1[7];
+ j = fftLen >> 2;
+ ptr1 = &pSrc[0];
- /* xb + xd */
- Xbplusd = xbIn + xdIn;
-
- /* yb + yd */
- Ybplusd = ybIn + ydIn;
+ /* Calculations of last stage */
+ do
+ {
+ xaIn = ptr1[0];
+ yaIn = ptr1[1];
+ xbIn = ptr1[2];
+ ybIn = ptr1[3];
+ xcIn = ptr1[4];
+ ycIn = ptr1[5];
+ xdIn = ptr1[6];
+ ydIn = ptr1[7];
- /* xa' = xa + xb + xc + xd */
- ptr1[0] = (Xaplusc + Xbplusd);
+ /* xa + xc */
+ Xaplusc = xaIn + xcIn;
+
+ /* xa - xc */
+ Xaminusc = xaIn - xcIn;
- /* (xb-xd) */
- Xbminusd = xbIn - xdIn;
+ /* ya + yc */
+ Yaplusc = yaIn + ycIn;
+
+ /* ya - yc */
+ Yaminusc = yaIn - ycIn;
+
+ /* xb + xd */
+ Xbplusd = xbIn + xdIn;
- /* ya' = ya + yb + yc + yd */
- ptr1[1] = (Yaplusc + Ybplusd);
+ /* yb + yd */
+ Ybplusd = ybIn + ydIn;
- /* (yb-yd) */
- Ybminusd = ybIn - ydIn;
+ /* (xb-xd) */
+ Xbminusd = xbIn - xdIn;
+
+ /* (yb-yd) */
+ Ybminusd = ybIn - ydIn;
- /* xc' = (xa-xb+xc-xd) */
- ptr1[2] = (Xaplusc - Xbplusd);
- /* yc' = (ya-yb+yc-yd) */
- ptr1[3] = (Yaplusc - Ybplusd);
- /* xb' = (xa+yb-xc-yd) */
- ptr1[4] = (Xaminusc + Ybminusd);
- /* yb' = (ya-xb-yc+xd) */
- ptr1[5] = (Yaminusc - Xbminusd);
- /* xd' = (xa-yb-xc+yd)) */
- ptr1[6] = (Xaminusc - Ybminusd);
- /* yd' = (ya+xb-yc-xd) */
- ptr1[7] = (Xbminusd + Yaminusc);
+ /* xa' = xa + xb + xc + xd */
+ a0 = (Xaplusc + Xbplusd);
+ /* ya' = ya + yb + yc + yd */
+ a1 = (Yaplusc + Ybplusd);
+ /* xc' = (xa-xb+xc-xd) */
+ a2 = (Xaplusc - Xbplusd);
+ /* yc' = (ya-yb+yc-yd) */
+ a3 = (Yaplusc - Ybplusd);
+ /* xb' = (xa+yb-xc-yd) */
+ a4 = (Xaminusc + Ybminusd);
+ /* yb' = (ya-xb-yc+xd) */
+ a5 = (Yaminusc - Xbminusd);
+ /* xd' = (xa-yb-xc+yd)) */
+ a6 = (Xaminusc - Ybminusd);
+ /* yd' = (ya+xb-yc-xd) */
+ a7 = (Xbminusd + Yaminusc);
+
+ ptr1[0] = a0;
+ ptr1[1] = a1;
+ ptr1[2] = a2;
+ ptr1[3] = a3;
+ ptr1[4] = a4;
+ ptr1[5] = a5;
+ ptr1[6] = a6;
+ ptr1[7] = a7;
- /* increment pointer by 8 */
- ptr1 = ptr1 + 8u;
-
- } while(--j);
+ /* increment pointer by 8 */
+ ptr1 += 8u;
+ } while(--j);
#else
- float32_t t1, t2, r1, r2, s1, s2;
+ float32_t t1, t2, r1, r2, s1, s2;
- /* Run the below code for Cortex-M0 */
+ /* Run the below code for Cortex-M0 */
- /* Initializations for the fft calculation */
- n2 = fftLen;
- n1 = n2;
- for (k = fftLen; k > 1u; k >>= 2u)
- {
- /* Initializations for the fft calculation */
- n1 = n2;
- n2 >>= 2u;
- ia1 = 0u;
+ /* Initializations for the fft calculation */
+ n2 = fftLen;
+ n1 = n2;
+ for (k = fftLen; k > 1u; k >>= 2u)
+ {
+ /* Initializations for the fft calculation */
+ n1 = n2;
+ n2 >>= 2u;
+ ia1 = 0u;
- /* FFT Calculation */
- for (j = 0u; j <= (n2 - 1u); j++)
- {
- /* index calculation for the coefficients */
- ia2 = ia1 + ia1;
- ia3 = ia2 + ia1;
- co1 = pCoef[ia1 * 2u];
- si1 = pCoef[(ia1 * 2u) + 1u];
- co2 = pCoef[ia2 * 2u];
- si2 = pCoef[(ia2 * 2u) + 1u];
- co3 = pCoef[ia3 * 2u];
- si3 = pCoef[(ia3 * 2u) + 1u];
-
- /* Twiddle coefficients index modifier */
- ia1 = ia1 + twidCoefModifier;
-
- for (i0 = j; i0 < fftLen; i0 += n1)
+ /* FFT Calculation */
+ j = 0;
+ do
{
- /* index calculation for the input as, */
- /* pSrc[i0 + 0], pSrc[i0 + fftLen/4], pSrc[i0 + fftLen/2], pSrc[i0 + 3fftLen/4] */
- i1 = i0 + n2;
- i2 = i1 + n2;
- i3 = i2 + n2;
+ /* index calculation for the coefficients */
+ ia2 = ia1 + ia1;
+ ia3 = ia2 + ia1;
+ co1 = pCoef[ia1 * 2u];
+ si1 = pCoef[(ia1 * 2u) + 1u];
+ co2 = pCoef[ia2 * 2u];
+ si2 = pCoef[(ia2 * 2u) + 1u];
+ co3 = pCoef[ia3 * 2u];
+ si3 = pCoef[(ia3 * 2u) + 1u];
- /* xa + xc */
- r1 = pSrc[(2u * i0)] + pSrc[(2u * i2)];
+ /* Twiddle coefficients index modifier */
+ ia1 = ia1 + twidCoefModifier;
- /* xa - xc */
- r2 = pSrc[(2u * i0)] - pSrc[(2u * i2)];
+ i0 = j;
+ do
+ {
+ /* index calculation for the input as, */
+ /* pSrc[i0 + 0], pSrc[i0 + fftLen/4], pSrc[i0 + fftLen/2], pSrc[i0 + 3fftLen/4] */
+ i1 = i0 + n2;
+ i2 = i1 + n2;
+ i3 = i2 + n2;
- /* ya + yc */
- s1 = pSrc[(2u * i0) + 1u] + pSrc[(2u * i2) + 1u];
+ /* xa + xc */
+ r1 = pSrc[(2u * i0)] + pSrc[(2u * i2)];
- /* ya - yc */
- s2 = pSrc[(2u * i0) + 1u] - pSrc[(2u * i2) + 1u];
+ /* xa - xc */
+ r2 = pSrc[(2u * i0)] - pSrc[(2u * i2)];
+
+ /* ya + yc */
+ s1 = pSrc[(2u * i0) + 1u] + pSrc[(2u * i2) + 1u];
- /* xb + xd */
- t1 = pSrc[2u * i1] + pSrc[2u * i3];
+ /* ya - yc */
+ s2 = pSrc[(2u * i0) + 1u] - pSrc[(2u * i2) + 1u];
+
+ /* xb + xd */
+ t1 = pSrc[2u * i1] + pSrc[2u * i3];
- /* xa' = xa + xb + xc + xd */
- pSrc[2u * i0] = r1 + t1;
+ /* xa' = xa + xb + xc + xd */
+ pSrc[2u * i0] = r1 + t1;
- /* xa + xc -(xb + xd) */
- r1 = r1 - t1;
+ /* xa + xc -(xb + xd) */
+ r1 = r1 - t1;
- /* yb + yd */
- t2 = pSrc[(2u * i1) + 1u] + pSrc[(2u * i3) + 1u];
+ /* yb + yd */
+ t2 = pSrc[(2u * i1) + 1u] + pSrc[(2u * i3) + 1u];
- /* ya' = ya + yb + yc + yd */
- pSrc[(2u * i0) + 1u] = s1 + t2;
+ /* ya' = ya + yb + yc + yd */
+ pSrc[(2u * i0) + 1u] = s1 + t2;
+
+ /* (ya + yc) - (yb + yd) */
+ s1 = s1 - t2;
- /* (ya + yc) - (yb + yd) */
- s1 = s1 - t2;
+ /* (yb - yd) */
+ t1 = pSrc[(2u * i1) + 1u] - pSrc[(2u * i3) + 1u];
- /* (yb - yd) */
- t1 = pSrc[(2u * i1) + 1u] - pSrc[(2u * i3) + 1u];
+ /* (xb - xd) */
+ t2 = pSrc[2u * i1] - pSrc[2u * i3];
- /* (xb - xd) */
- t2 = pSrc[2u * i1] - pSrc[2u * i3];
+ /* xc' = (xa-xb+xc-xd)co2 + (ya-yb+yc-yd)(si2) */
+ pSrc[2u * i1] = (r1 * co2) + (s1 * si2);
- /* xc' = (xa-xb+xc-xd)co2 + (ya-yb+yc-yd)(si2) */
- pSrc[2u * i1] = (r1 * co2) + (s1 * si2);
+ /* yc' = (ya-yb+yc-yd)co2 - (xa-xb+xc-xd)(si2) */
+ pSrc[(2u * i1) + 1u] = (s1 * co2) - (r1 * si2);
- /* yc' = (ya-yb+yc-yd)co2 - (xa-xb+xc-xd)(si2) */
- pSrc[(2u * i1) + 1u] = (s1 * co2) - (r1 * si2);
+ /* (xa - xc) + (yb - yd) */
+ r1 = r2 + t1;
- /* (xa - xc) + (yb - yd) */
- r1 = r2 + t1;
+ /* (xa - xc) - (yb - yd) */
+ r2 = r2 - t1;
- /* (xa - xc) - (yb - yd) */
- r2 = r2 - t1;
+ /* (ya - yc) - (xb - xd) */
+ s1 = s2 - t2;
- /* (ya - yc) - (xb - xd) */
- s1 = s2 - t2;
+ /* (ya - yc) + (xb - xd) */
+ s2 = s2 + t2;
- /* (ya - yc) + (xb - xd) */
- s2 = s2 + t2;
+ /* xb' = (xa+yb-xc-yd)co1 + (ya-xb-yc+xd)(si1) */
+ pSrc[2u * i2] = (r1 * co1) + (s1 * si1);
- /* xb' = (xa+yb-xc-yd)co1 + (ya-xb-yc+xd)(si1) */
- pSrc[2u * i2] = (r1 * co1) + (s1 * si1);
+ /* yb' = (ya-xb-yc+xd)co1 - (xa+yb-xc-yd)(si1) */
+ pSrc[(2u * i2) + 1u] = (s1 * co1) - (r1 * si1);
- /* yb' = (ya-xb-yc+xd)co1 - (xa+yb-xc-yd)(si1) */
- pSrc[(2u * i2) + 1u] = (s1 * co1) - (r1 * si1);
-
- /* xd' = (xa-yb-xc+yd)co3 + (ya+xb-yc-xd)(si3) */
- pSrc[2u * i3] = (r2 * co3) + (s2 * si3);
+ /* xd' = (xa-yb-xc+yd)co3 + (ya+xb-yc-xd)(si3) */
+ pSrc[2u * i3] = (r2 * co3) + (s2 * si3);
- /* yd' = (ya+xb-yc-xd)co3 - (xa-yb-xc+yd)(si3) */
- pSrc[(2u * i3) + 1u] = (s2 * co3) - (r2 * si3);
- }
- }
- twidCoefModifier <<= 2u;
- }
+ /* yd' = (ya+xb-yc-xd)co3 - (xa-yb-xc+yd)(si3) */
+ pSrc[(2u * i3) + 1u] = (s2 * co3) - (r2 * si3);
+
+ i0 += n1;
+ } while( i0 < fftLen);
+ j++;
+ } while(j <= (n2 - 1u));
+ twidCoefModifier <<= 2u;
+ }
-#endif /* #ifndef ARM_MATH_CM0 */
+#endif /* #ifndef ARM_MATH_CM0_FAMILY_FAMILY */
}
/*
- * @brief Core function for the floating-point CIFFT butterfly process.
- * @param[in, out] *pSrc points to the in-place buffer of floating-point data type.
- * @param[in] fftLen length of the FFT.
- * @param[in] *pCoef points to twiddle coefficient buffer.
- * @param[in] twidCoefModifier twiddle coefficient modifier that supports different size FFTs with the same twiddle factor table.
- * @param[in] onebyfftLen value of 1/fftLen.
- * @return none.
- */
+* @brief Core function for the floating-point CIFFT butterfly process.
+* @param[in, out] *pSrc points to the in-place buffer of floating-point data type.
+* @param[in] fftLen length of the FFT.
+* @param[in] *pCoef points to twiddle coefficient buffer.
+* @param[in] twidCoefModifier twiddle coefficient modifier that supports different size FFTs with the same twiddle factor table.
+* @param[in] onebyfftLen value of 1/fftLen.
+* @return none.
+*/
void arm_radix4_butterfly_inverse_f32(
- float32_t * pSrc,
- uint16_t fftLen,
- float32_t * pCoef,
- uint16_t twidCoefModifier,
- float32_t onebyfftLen)
+float32_t * pSrc,
+uint16_t fftLen,
+float32_t * pCoef,
+uint16_t twidCoefModifier,
+float32_t onebyfftLen)
{
- float32_t co1, co2, co3, si1, si2, si3;
- uint32_t ia1, ia2, ia3;
- uint32_t i0, i1, i2, i3;
- uint32_t n1, n2, j, k;
+ float32_t co1, co2, co3, si1, si2, si3;
+ uint32_t ia1, ia2, ia3;
+ uint32_t i0, i1, i2, i3;
+ uint32_t n1, n2, j, k;
-#ifndef ARM_MATH_CM0
+#ifndef ARM_MATH_CM0_FAMILY_FAMILY
- float32_t xaIn, yaIn, xbIn, ybIn, xcIn, ycIn, xdIn, ydIn;
- float32_t Xaplusc, Xbplusd, Yaplusc, Ybplusd, Xaminusc, Xbminusd, Yaminusc,
- Ybminusd;
- float32_t Xb12C_out, Yb12C_out, Xc12C_out, Yc12C_out, Xd12C_out, Yd12C_out;
- float32_t Xb12_out, Yb12_out, Xc12_out, Yc12_out, Xd12_out, Yd12_out;
- float32_t *ptr1;
+ float32_t xaIn, yaIn, xbIn, ybIn, xcIn, ycIn, xdIn, ydIn;
+ float32_t Xaplusc, Xbplusd, Yaplusc, Ybplusd, Xaminusc, Xbminusd, Yaminusc,
+ Ybminusd;
+ float32_t Xb12C_out, Yb12C_out, Xc12C_out, Yc12C_out, Xd12C_out, Yd12C_out;
+ float32_t Xb12_out, Yb12_out, Xc12_out, Yc12_out, Xd12_out, Yd12_out;
+ float32_t *ptr1;
+ float32_t p0,p1,p2,p3,p4,p5,p6,p7;
+ float32_t a0,a1,a2,a3,a4,a5,a6,a7;
- /* Initializations for the first stage */
- n2 = fftLen;
- n1 = n2;
-
- /* n2 = fftLen/4 */
- n2 >>= 2u;
- i0 = 0u;
- ia1 = 0u;
-
- j = n2;
+ /* Initializations for the first stage */
+ n2 = fftLen;
+ n1 = n2;
- /* Calculation of first stage */
- do
- {
- /* index calculation for the input as, */
- /* pSrc[i0 + 0], pSrc[i0 + fftLen/4], pSrc[i0 + fftLen/2], pSrc[i0 + 3fftLen/4] */
- i1 = i0 + n2;
- i2 = i1 + n2;
- i3 = i2 + n2;
-
- /* Butterfly implementation */
- xaIn = pSrc[(2u * i0)];
- yaIn = pSrc[(2u * i0) + 1u];
-
- xcIn = pSrc[(2u * i2)];
- ycIn = pSrc[(2u * i2) + 1u];
-
- xbIn = pSrc[(2u * i1)];
- ybIn = pSrc[(2u * i1) + 1u];
+ /* n2 = fftLen/4 */
+ n2 >>= 2u;
+ i0 = 0u;
+ ia1 = 0u;
- xdIn = pSrc[(2u * i3)];
- ydIn = pSrc[(2u * i3) + 1u];
-
- /* xa + xc */
- Xaplusc = xaIn + xcIn;
- /* xb + xd */
- Xbplusd = xbIn + xdIn;
- /* ya + yc */
- Yaplusc = yaIn + ycIn;
- /* yb + yd */
- Ybplusd = ybIn + ydIn;
+ j = n2;
- /* index calculation for the coefficients */
- ia2 = ia1 + ia1;
- co2 = pCoef[ia2 * 2u];
- si2 = pCoef[(ia2 * 2u) + 1u];
-
- /* xa - xc */
- Xaminusc = xaIn - xcIn;
- /* xb - xd */
- Xbminusd = xbIn - xdIn;
- /* ya - yc */
- Yaminusc = yaIn - ycIn;
- /* yb - yd */
- Ybminusd = ybIn - ydIn;
-
- /* xa' = xa + xb + xc + xd */
- pSrc[(2u * i0)] = Xaplusc + Xbplusd;
-
- /* ya' = ya + yb + yc + yd */
- pSrc[(2u * i0) + 1u] = Yaplusc + Ybplusd;
+ /* Calculation of first stage */
+ do
+ {
+ /* index calculation for the input as, */
+ /* pSrc[i0 + 0], pSrc[i0 + fftLen/4], pSrc[i0 + fftLen/2], pSrc[i0 + 3fftLen/4] */
+ i1 = i0 + n2;
+ i2 = i1 + n2;
+ i3 = i2 + n2;
- /* (xa - xc) - (yb - yd) */
- Xb12C_out = (Xaminusc - Ybminusd);
- /* (ya - yc) + (xb - xd) */
- Yb12C_out = (Yaminusc + Xbminusd);
- /* (xa + xc) - (xb + xd) */
- Xc12C_out = (Xaplusc - Xbplusd);
- /* (ya + yc) - (yb + yd) */
- Yc12C_out = (Yaplusc - Ybplusd);
- /* (xa - xc) + (yb - yd) */
- Xd12C_out = (Xaminusc + Ybminusd);
- /* (ya - yc) - (xb - xd) */
- Yd12C_out = (Yaminusc - Xbminusd);
+ /* Butterfly implementation */
+ xaIn = pSrc[(2u * i0)];
+ yaIn = pSrc[(2u * i0) + 1u];
- co1 = pCoef[ia1 * 2u];
- si1 = pCoef[(ia1 * 2u) + 1u];
+ xcIn = pSrc[(2u * i2)];
+ ycIn = pSrc[(2u * i2) + 1u];
- /* index calculation for the coefficients */
- ia3 = ia2 + ia1;
- co3 = pCoef[ia3 * 2u];
- si3 = pCoef[(ia3 * 2u) + 1u];
-
- Xb12_out = Xb12C_out * co1;
- Yb12_out = Yb12C_out * co1;
- Xc12_out = Xc12C_out * co2;
- Yc12_out = Yc12C_out * co2;
- Xd12_out = Xd12C_out * co3;
- Yd12_out = Yd12C_out * co3;
+ xbIn = pSrc[(2u * i1)];
+ ybIn = pSrc[(2u * i1) + 1u];
- /* xb' = (xa+yb-xc-yd)co1 - (ya-xb-yc+xd)(si1) */
- Xb12_out -= Yb12C_out * si1;
- /* yb' = (ya-xb-yc+xd)co1 + (xa+yb-xc-yd)(si1) */
- Yb12_out += Xb12C_out * si1;
- /* xc' = (xa-xb+xc-xd)co2 - (ya-yb+yc-yd)(si2) */
- Xc12_out -= Yc12C_out * si2;
- /* yc' = (ya-yb+yc-yd)co2 + (xa-xb+xc-xd)(si2) */
- Yc12_out += Xc12C_out * si2;
- /* xd' = (xa-yb-xc+yd)co3 - (ya+xb-yc-xd)(si3) */
- Xd12_out -= Yd12C_out * si3;
- /* yd' = (ya+xb-yc-xd)co3 + (xa-yb-xc+yd)(si3) */
- Yd12_out += Xd12C_out * si3;
-
- /* xc' = (xa-xb+xc-xd)co2 - (ya-yb+yc-yd)(si2) */
- pSrc[2u * i1] = Xc12_out;
-
- /* yc' = (ya-yb+yc-yd)co2 + (xa-xb+xc-xd)(si2) */
- pSrc[(2u * i1) + 1u] = Yc12_out;
-
- /* xb' = (xa+yb-xc-yd)co1 - (ya-xb-yc+xd)(si1) */
- pSrc[2u * i2] = Xb12_out;
-
- /* yb' = (ya-xb-yc+xd)co1 + (xa+yb-xc-yd)(si1) */
- pSrc[(2u * i2) + 1u] = Yb12_out;
+ xdIn = pSrc[(2u * i3)];
+ ydIn = pSrc[(2u * i3) + 1u];
- /* xd' = (xa-yb-xc+yd)co3 - (ya+xb-yc-xd)(si3) */
- pSrc[2u * i3] = Xd12_out;
-
- /* yd' = (ya+xb-yc-xd)co3 + (xa-yb-xc+yd)(si3) */
- pSrc[(2u * i3) + 1u] = Yd12_out;
-
- /* Twiddle coefficients index modifier */
- ia1 = ia1 + twidCoefModifier;
-
- /* Updating input index */
- i0 = i0 + 1u;
-
- } while(--j);
+ /* xa + xc */
+ Xaplusc = xaIn + xcIn;
+ /* xb + xd */
+ Xbplusd = xbIn + xdIn;
+ /* ya + yc */
+ Yaplusc = yaIn + ycIn;
+ /* yb + yd */
+ Ybplusd = ybIn + ydIn;
- twidCoefModifier <<= 2u;
-
- /* Calculation of second stage to excluding last stage */
- for (k = fftLen / 4; k > 4u; k >>= 2u)
- {
- /* Initializations for the first stage */
- n1 = n2;
- n2 >>= 2u;
- ia1 = 0u;
-
- /* Calculation of first stage */
- for (j = 0u; j <= (n2 - 1u); j++)
- {
/* index calculation for the coefficients */
ia2 = ia1 + ia1;
- ia3 = ia2 + ia1;
+ co2 = pCoef[ia2 * 2u];
+ si2 = pCoef[(ia2 * 2u) + 1u];
+
+ /* xa - xc */
+ Xaminusc = xaIn - xcIn;
+ /* xb - xd */
+ Xbminusd = xbIn - xdIn;
+ /* ya - yc */
+ Yaminusc = yaIn - ycIn;
+ /* yb - yd */
+ Ybminusd = ybIn - ydIn;
+
+ /* xa' = xa + xb + xc + xd */
+ pSrc[(2u * i0)] = Xaplusc + Xbplusd;
+
+ /* ya' = ya + yb + yc + yd */
+ pSrc[(2u * i0) + 1u] = Yaplusc + Ybplusd;
+
+ /* (xa - xc) - (yb - yd) */
+ Xb12C_out = (Xaminusc - Ybminusd);
+ /* (ya - yc) + (xb - xd) */
+ Yb12C_out = (Yaminusc + Xbminusd);
+ /* (xa + xc) - (xb + xd) */
+ Xc12C_out = (Xaplusc - Xbplusd);
+ /* (ya + yc) - (yb + yd) */
+ Yc12C_out = (Yaplusc - Ybplusd);
+ /* (xa - xc) + (yb - yd) */
+ Xd12C_out = (Xaminusc + Ybminusd);
+ /* (ya - yc) - (xb - xd) */
+ Yd12C_out = (Yaminusc - Xbminusd);
+
co1 = pCoef[ia1 * 2u];
si1 = pCoef[(ia1 * 2u) + 1u];
- co2 = pCoef[ia2 * 2u];
- si2 = pCoef[(ia2 * 2u) + 1u];
+
+ /* index calculation for the coefficients */
+ ia3 = ia2 + ia1;
co3 = pCoef[ia3 * 2u];
si3 = pCoef[(ia3 * 2u) + 1u];
+ Xb12_out = Xb12C_out * co1;
+ Yb12_out = Yb12C_out * co1;
+ Xc12_out = Xc12C_out * co2;
+ Yc12_out = Yc12C_out * co2;
+ Xd12_out = Xd12C_out * co3;
+ Yd12_out = Yd12C_out * co3;
+
+ /* xb' = (xa+yb-xc-yd)co1 - (ya-xb-yc+xd)(si1) */
+ //Xb12_out -= Yb12C_out * si1;
+ p0 = Yb12C_out * si1;
+ /* yb' = (ya-xb-yc+xd)co1 + (xa+yb-xc-yd)(si1) */
+ //Yb12_out += Xb12C_out * si1;
+ p1 = Xb12C_out * si1;
+ /* xc' = (xa-xb+xc-xd)co2 - (ya-yb+yc-yd)(si2) */
+ //Xc12_out -= Yc12C_out * si2;
+ p2 = Yc12C_out * si2;
+ /* yc' = (ya-yb+yc-yd)co2 + (xa-xb+xc-xd)(si2) */
+ //Yc12_out += Xc12C_out * si2;
+ p3 = Xc12C_out * si2;
+ /* xd' = (xa-yb-xc+yd)co3 - (ya+xb-yc-xd)(si3) */
+ //Xd12_out -= Yd12C_out * si3;
+ p4 = Yd12C_out * si3;
+ /* yd' = (ya+xb-yc-xd)co3 + (xa-yb-xc+yd)(si3) */
+ //Yd12_out += Xd12C_out * si3;
+ p5 = Xd12C_out * si3;
+
+ Xb12_out -= p0;
+ Yb12_out += p1;
+ Xc12_out -= p2;
+ Yc12_out += p3;
+ Xd12_out -= p4;
+ Yd12_out += p5;
+
+ /* xc' = (xa-xb+xc-xd)co2 - (ya-yb+yc-yd)(si2) */
+ pSrc[2u * i1] = Xc12_out;
+
+ /* yc' = (ya-yb+yc-yd)co2 + (xa-xb+xc-xd)(si2) */
+ pSrc[(2u * i1) + 1u] = Yc12_out;
+
+ /* xb' = (xa+yb-xc-yd)co1 - (ya-xb-yc+xd)(si1) */
+ pSrc[2u * i2] = Xb12_out;
+
+ /* yb' = (ya-xb-yc+xd)co1 + (xa+yb-xc-yd)(si1) */
+ pSrc[(2u * i2) + 1u] = Yb12_out;
+
+ /* xd' = (xa-yb-xc+yd)co3 - (ya+xb-yc-xd)(si3) */
+ pSrc[2u * i3] = Xd12_out;
+
+ /* yd' = (ya+xb-yc-xd)co3 + (xa-yb-xc+yd)(si3) */
+ pSrc[(2u * i3) + 1u] = Yd12_out;
+
/* Twiddle coefficients index modifier */
ia1 = ia1 + twidCoefModifier;
- for (i0 = j; i0 < fftLen; i0 += n1)
- {
- /* index calculation for the input as, */
- /* pSrc[i0 + 0], pSrc[i0 + fftLen/4], pSrc[i0 + fftLen/2], pSrc[i0 + 3fftLen/4] */
- i1 = i0 + n2;
- i2 = i1 + n2;
- i3 = i2 + n2;
+ /* Updating input index */
+ i0 = i0 + 1u;
+
+ } while(--j);
+
+ twidCoefModifier <<= 2u;
- xaIn = pSrc[(2u * i0)];
- yaIn = pSrc[(2u * i0) + 1u];
-
- xbIn = pSrc[(2u * i1)];
- ybIn = pSrc[(2u * i1) + 1u];
-
- xcIn = pSrc[(2u * i2)];
- ycIn = pSrc[(2u * i2) + 1u];
+ /* Calculation of second stage to excluding last stage */
+ for (k = fftLen >> 2u; k > 4u; k >>= 2u)
+ {
+ /* Initializations for the first stage */
+ n1 = n2;
+ n2 >>= 2u;
+ ia1 = 0u;
- xdIn = pSrc[(2u * i3)];
- ydIn = pSrc[(2u * i3) + 1u];
+ /* Calculation of first stage */
+ j = 0;
+ do
+ {
+ /* index calculation for the coefficients */
+ ia2 = ia1 + ia1;
+ ia3 = ia2 + ia1;
+ co1 = pCoef[ia1 * 2u];
+ si1 = pCoef[(ia1 * 2u) + 1u];
+ co2 = pCoef[ia2 * 2u];
+ si2 = pCoef[(ia2 * 2u) + 1u];
+ co3 = pCoef[ia3 * 2u];
+ si3 = pCoef[(ia3 * 2u) + 1u];
- /* xa - xc */
- Xaminusc = xaIn - xcIn;
- /* (xb - xd) */
- Xbminusd = xbIn - xdIn;
- /* ya - yc */
- Yaminusc = yaIn - ycIn;
- /* (yb - yd) */
- Ybminusd = ybIn - ydIn;
+ /* Twiddle coefficients index modifier */
+ ia1 = ia1 + twidCoefModifier;
- /* xa + xc */
- Xaplusc = xaIn + xcIn;
- /* xb + xd */
- Xbplusd = xbIn + xdIn;
- /* ya + yc */
- Yaplusc = yaIn + ycIn;
- /* yb + yd */
- Ybplusd = ybIn + ydIn;
+ i0 = j;
+ do
+ {
+ /* index calculation for the input as, */
+ /* pSrc[i0 + 0], pSrc[i0 + fftLen/4], pSrc[i0 + fftLen/2], pSrc[i0 + 3fftLen/4] */
+ i1 = i0 + n2;
+ i2 = i1 + n2;
+ i3 = i2 + n2;
+
+ xaIn = pSrc[(2u * i0)];
+ yaIn = pSrc[(2u * i0) + 1u];
+
+ xbIn = pSrc[(2u * i1)];
+ ybIn = pSrc[(2u * i1) + 1u];
- /* (xa - xc) - (yb - yd) */
- Xb12C_out = (Xaminusc - Ybminusd);
- /* (ya - yc) + (xb - xd) */
- Yb12C_out = (Yaminusc + Xbminusd);
- /* xa + xc -(xb + xd) */
- Xc12C_out = (Xaplusc - Xbplusd);
- /* (ya + yc) - (yb + yd) */
- Yc12C_out = (Yaplusc - Ybplusd);
- /* (xa - xc) + (yb - yd) */
- Xd12C_out = (Xaminusc + Ybminusd);
- /* (ya - yc) - (xb - xd) */
- Yd12C_out = (Yaminusc - Xbminusd);
+ xcIn = pSrc[(2u * i2)];
+ ycIn = pSrc[(2u * i2) + 1u];
+
+ xdIn = pSrc[(2u * i3)];
+ ydIn = pSrc[(2u * i3) + 1u];
- pSrc[(2u * i0)] = Xaplusc + Xbplusd;
- pSrc[(2u * i0) + 1u] = Yaplusc + Ybplusd;
-
- Xb12_out = Xb12C_out * co1;
- Yb12_out = Yb12C_out * co1;
- Xc12_out = Xc12C_out * co2;
- Yc12_out = Yc12C_out * co2;
- Xd12_out = Xd12C_out * co3;
- Yd12_out = Yd12C_out * co3;
+ /* xa - xc */
+ Xaminusc = xaIn - xcIn;
+ /* (xb - xd) */
+ Xbminusd = xbIn - xdIn;
+ /* ya - yc */
+ Yaminusc = yaIn - ycIn;
+ /* (yb - yd) */
+ Ybminusd = ybIn - ydIn;
- /* xb' = (xa+yb-xc-yd)co1 - (ya-xb-yc+xd)(si1) */
- Xb12_out -= Yb12C_out * si1;
- /* yb' = (ya-xb-yc+xd)co1 + (xa+yb-xc-yd)(si1) */
- Yb12_out += Xb12C_out * si1;
- /* xc' = (xa-xb+xc-xd)co2 - (ya-yb+yc-yd)(si2) */
- Xc12_out -= Yc12C_out * si2;
- /* yc' = (ya-yb+yc-yd)co2 + (xa-xb+xc-xd)(si2) */
- Yc12_out += Xc12C_out * si2;
- /* xd' = (xa-yb-xc+yd)co3 - (ya+xb-yc-xd)(si3) */
- Xd12_out -= Yd12C_out * si3;
- /* yd' = (ya+xb-yc-xd)co3 + (xa-yb-xc+yd)(si3) */
- Yd12_out += Xd12C_out * si3;
+ /* xa + xc */
+ Xaplusc = xaIn + xcIn;
+ /* xb + xd */
+ Xbplusd = xbIn + xdIn;
+ /* ya + yc */
+ Yaplusc = yaIn + ycIn;
+ /* yb + yd */
+ Ybplusd = ybIn + ydIn;
- /* xc' = (xa-xb+xc-xd)co2 - (ya-yb+yc-yd)(si2) */
- pSrc[2u * i1] = Xc12_out;
-
- /* yc' = (ya-yb+yc-yd)co2 + (xa-xb+xc-xd)(si2) */
- pSrc[(2u * i1) + 1u] = Yc12_out;
+ /* (xa - xc) - (yb - yd) */
+ Xb12C_out = (Xaminusc - Ybminusd);
+ /* (ya - yc) + (xb - xd) */
+ Yb12C_out = (Yaminusc + Xbminusd);
+ /* xa + xc -(xb + xd) */
+ Xc12C_out = (Xaplusc - Xbplusd);
+ /* (ya + yc) - (yb + yd) */
+ Yc12C_out = (Yaplusc - Ybplusd);
+ /* (xa - xc) + (yb - yd) */
+ Xd12C_out = (Xaminusc + Ybminusd);
+ /* (ya - yc) - (xb - xd) */
+ Yd12C_out = (Yaminusc - Xbminusd);
- /* xb' = (xa+yb-xc-yd)co1 - (ya-xb-yc+xd)(si1) */
- pSrc[2u * i2] = Xb12_out;
+ pSrc[(2u * i0)] = Xaplusc + Xbplusd;
+ pSrc[(2u * i0) + 1u] = Yaplusc + Ybplusd;
- /* yb' = (ya-xb-yc+xd)co1 + (xa+yb-xc-yd)(si1) */
- pSrc[(2u * i2) + 1u] = Yb12_out;
+ Xb12_out = Xb12C_out * co1;
+ Yb12_out = Yb12C_out * co1;
+ Xc12_out = Xc12C_out * co2;
+ Yc12_out = Yc12C_out * co2;
+ Xd12_out = Xd12C_out * co3;
+ Yd12_out = Yd12C_out * co3;
- /* xd' = (xa-yb-xc+yd)co3 - (ya+xb-yc-xd)(si3) */
- pSrc[2u * i3] = Xd12_out;
-
- /* yd' = (ya+xb-yc-xd)co3 + (xa-yb-xc+yd)(si3) */
- pSrc[(2u * i3) + 1u] = Yd12_out;
+ /* xb' = (xa+yb-xc-yd)co1 - (ya-xb-yc+xd)(si1) */
+ //Xb12_out -= Yb12C_out * si1;
+ p0 = Yb12C_out * si1;
+ /* yb' = (ya-xb-yc+xd)co1 + (xa+yb-xc-yd)(si1) */
+ //Yb12_out += Xb12C_out * si1;
+ p1 = Xb12C_out * si1;
+ /* xc' = (xa-xb+xc-xd)co2 - (ya-yb+yc-yd)(si2) */
+ //Xc12_out -= Yc12C_out * si2;
+ p2 = Yc12C_out * si2;
+ /* yc' = (ya-yb+yc-yd)co2 + (xa-xb+xc-xd)(si2) */
+ //Yc12_out += Xc12C_out * si2;
+ p3 = Xc12C_out * si2;
+ /* xd' = (xa-yb-xc+yd)co3 - (ya+xb-yc-xd)(si3) */
+ //Xd12_out -= Yd12C_out * si3;
+ p4 = Yd12C_out * si3;
+ /* yd' = (ya+xb-yc-xd)co3 + (xa-yb-xc+yd)(si3) */
+ //Yd12_out += Xd12C_out * si3;
+ p5 = Xd12C_out * si3;
+
+ Xb12_out -= p0;
+ Yb12_out += p1;
+ Xc12_out -= p2;
+ Yc12_out += p3;
+ Xd12_out -= p4;
+ Yd12_out += p5;
- }
- }
- twidCoefModifier <<= 2u;
- }
- /* Initializations of last stage */
+ /* xc' = (xa-xb+xc-xd)co2 - (ya-yb+yc-yd)(si2) */
+ pSrc[2u * i1] = Xc12_out;
- j = fftLen >> 2;
- ptr1 = &pSrc[0];
-
- /* Calculations of last stage */
- do
- {
+ /* yc' = (ya-yb+yc-yd)co2 + (xa-xb+xc-xd)(si2) */
+ pSrc[(2u * i1) + 1u] = Yc12_out;
- xaIn = ptr1[0];
- xcIn = ptr1[4];
- yaIn = ptr1[1];
- ycIn = ptr1[5];
+ /* xb' = (xa+yb-xc-yd)co1 - (ya-xb-yc+xd)(si1) */
+ pSrc[2u * i2] = Xb12_out;
+
+ /* yb' = (ya-xb-yc+xd)co1 + (xa+yb-xc-yd)(si1) */
+ pSrc[(2u * i2) + 1u] = Yb12_out;
- /* Butterfly implementation */
- /* xa + xc */
- Xaplusc = xaIn + xcIn;
+ /* xd' = (xa-yb-xc+yd)co3 - (ya+xb-yc-xd)(si3) */
+ pSrc[2u * i3] = Xd12_out;
- xbIn = ptr1[2];
+ /* yd' = (ya+xb-yc-xd)co3 + (xa-yb-xc+yd)(si3) */
+ pSrc[(2u * i3) + 1u] = Yd12_out;
- /* xa - xc */
- Xaminusc = xaIn - xcIn;
+ i0 += n1;
+ } while(i0 < fftLen);
+ j++;
+ } while(j <= (n2 - 1u));
+ twidCoefModifier <<= 2u;
+ }
+ /* Initializations of last stage */
- xdIn = ptr1[6];
+ j = fftLen >> 2;
+ ptr1 = &pSrc[0];
- /* ya + yc */
- Yaplusc = yaIn + ycIn;
-
- ybIn = ptr1[3];
-
- /* ya - yc */
- Yaminusc = yaIn - ycIn;
+ /* Calculations of last stage */
+ do
+ {
+ xaIn = ptr1[0];
+ yaIn = ptr1[1];
+ xbIn = ptr1[2];
+ ybIn = ptr1[3];
+ xcIn = ptr1[4];
+ ycIn = ptr1[5];
+ xdIn = ptr1[6];
+ ydIn = ptr1[7];
- ydIn = ptr1[7];
+ /* Butterfly implementation */
+ /* xa + xc */
+ Xaplusc = xaIn + xcIn;
- /* xc + xd */
- Xbplusd = xbIn + xdIn;
+ /* xa - xc */
+ Xaminusc = xaIn - xcIn;
- /* yb + yd */
- Ybplusd = ybIn + ydIn;
+ /* ya + yc */
+ Yaplusc = yaIn + ycIn;
- /* xa' = xa + xb + xc + xd */
- ptr1[0] = (Xaplusc + Xbplusd) * onebyfftLen;
+ /* ya - yc */
+ Yaminusc = yaIn - ycIn;
- /* (xb-xd) */
- Xbminusd = xbIn - xdIn;
+ /* xb + xd */
+ Xbplusd = xbIn + xdIn;
- /* ya' = ya + yb + yc + yd */
- ptr1[1] = (Yaplusc + Ybplusd) * onebyfftLen;
+ /* yb + yd */
+ Ybplusd = ybIn + ydIn;
- /* (yb-yd) */
- Ybminusd = ybIn - ydIn;
+ /* (xb-xd) */
+ Xbminusd = xbIn - xdIn;
- /* xc' = (xa-xb+xc-xd) * onebyfftLen */
- ptr1[2] = (Xaplusc - Xbplusd) * onebyfftLen;
-
- /* yc' = (ya-yb+yc-yd) * onebyfftLen */
- ptr1[3] = (Yaplusc - Ybplusd) * onebyfftLen;
-
- /* xb' = (xa-yb-xc+yd) * onebyfftLen */
- ptr1[4] = (Xaminusc - Ybminusd) * onebyfftLen;
+ /* (yb-yd) */
+ Ybminusd = ybIn - ydIn;
+
+ /* xa' = (xa+xb+xc+xd) * onebyfftLen */
+ a0 = (Xaplusc + Xbplusd);
+ /* ya' = (ya+yb+yc+yd) * onebyfftLen */
+ a1 = (Yaplusc + Ybplusd);
+ /* xc' = (xa-xb+xc-xd) * onebyfftLen */
+ a2 = (Xaplusc - Xbplusd);
+ /* yc' = (ya-yb+yc-yd) * onebyfftLen */
+ a3 = (Yaplusc - Ybplusd);
+ /* xb' = (xa-yb-xc+yd) * onebyfftLen */
+ a4 = (Xaminusc - Ybminusd);
+ /* yb' = (ya+xb-yc-xd) * onebyfftLen */
+ a5 = (Yaminusc + Xbminusd);
+ /* xd' = (xa-yb-xc+yd) * onebyfftLen */
+ a6 = (Xaminusc + Ybminusd);
+ /* yd' = (ya-xb-yc+xd) * onebyfftLen */
+ a7 = (Yaminusc - Xbminusd);
+
+ p0 = a0 * onebyfftLen;
+ p1 = a1 * onebyfftLen;
+ p2 = a2 * onebyfftLen;
+ p3 = a3 * onebyfftLen;
+ p4 = a4 * onebyfftLen;
+ p5 = a5 * onebyfftLen;
+ p6 = a6 * onebyfftLen;
+ p7 = a7 * onebyfftLen;
+
+ /* xa' = (xa+xb+xc+xd) * onebyfftLen */
+ ptr1[0] = p0;
+ /* ya' = (ya+yb+yc+yd) * onebyfftLen */
+ ptr1[1] = p1;
+ /* xc' = (xa-xb+xc-xd) * onebyfftLen */
+ ptr1[2] = p2;
+ /* yc' = (ya-yb+yc-yd) * onebyfftLen */
+ ptr1[3] = p3;
+ /* xb' = (xa-yb-xc+yd) * onebyfftLen */
+ ptr1[4] = p4;
+ /* yb' = (ya+xb-yc-xd) * onebyfftLen */
+ ptr1[5] = p5;
+ /* xd' = (xa-yb-xc+yd) * onebyfftLen */
+ ptr1[6] = p6;
+ /* yd' = (ya-xb-yc+xd) * onebyfftLen */
+ ptr1[7] = p7;
- /* yb' = (ya+xb-yc-xd) * onebyfftLen */
- ptr1[5] = (Yaminusc + Xbminusd) * onebyfftLen;
-
- /* xd' = (xa-yb-xc+yd) * onebyfftLen */
- ptr1[6] = (Xaminusc + Ybminusd) * onebyfftLen;
+ /* increment source pointer by 8 for next calculations */
+ ptr1 = ptr1 + 8u;
- /* yd' = (ya-xb-yc+xd) * onebyfftLen */
- ptr1[7] = (Yaminusc - Xbminusd) * onebyfftLen;
-
- /* increment source pointer by 8 for next calculations */
- ptr1 = ptr1 + 8u;
-
- } while(--j);
+ } while(--j);
#else
- float32_t t1, t2, r1, r2, s1, s2;
+ float32_t t1, t2, r1, r2, s1, s2;
- /* Run the below code for Cortex-M0 */
+ /* Run the below code for Cortex-M0 */
- /* Initializations for the first stage */
- n2 = fftLen;
- n1 = n2;
+ /* Initializations for the first stage */
+ n2 = fftLen;
+ n1 = n2;
- /* Calculation of first stage */
- for (k = fftLen; k > 4u; k >>= 2u)
- {
- /* Initializations for the first stage */
- n1 = n2;
- n2 >>= 2u;
- ia1 = 0u;
+ /* Calculation of first stage */
+ for (k = fftLen; k > 4u; k >>= 2u)
+ {
+ /* Initializations for the first stage */
+ n1 = n2;
+ n2 >>= 2u;
+ ia1 = 0u;
- /* Calculation of first stage */
- for (j = 0u; j <= (n2 - 1u); j++)
- {
- /* index calculation for the coefficients */
- ia2 = ia1 + ia1;
- ia3 = ia2 + ia1;
- co1 = pCoef[ia1 * 2u];
- si1 = pCoef[(ia1 * 2u) + 1u];
- co2 = pCoef[ia2 * 2u];
- si2 = pCoef[(ia2 * 2u) + 1u];
- co3 = pCoef[ia3 * 2u];
- si3 = pCoef[(ia3 * 2u) + 1u];
+ /* Calculation of first stage */
+ j = 0;
+ do
+ {
+ /* index calculation for the coefficients */
+ ia2 = ia1 + ia1;
+ ia3 = ia2 + ia1;
+ co1 = pCoef[ia1 * 2u];
+ si1 = pCoef[(ia1 * 2u) + 1u];
+ co2 = pCoef[ia2 * 2u];
+ si2 = pCoef[(ia2 * 2u) + 1u];
+ co3 = pCoef[ia3 * 2u];
+ si3 = pCoef[(ia3 * 2u) + 1u];
+
+ /* Twiddle coefficients index modifier */
+ ia1 = ia1 + twidCoefModifier;
- /* Twiddle coefficients index modifier */
- ia1 = ia1 + twidCoefModifier;
+ i0 = j;
+ do
+ {
+ /* index calculation for the input as, */
+ /* pSrc[i0 + 0], pSrc[i0 + fftLen/4], pSrc[i0 + fftLen/2], pSrc[i0 + 3fftLen/4] */
+ i1 = i0 + n2;
+ i2 = i1 + n2;
+ i3 = i2 + n2;
+
+ /* xa + xc */
+ r1 = pSrc[(2u * i0)] + pSrc[(2u * i2)];
- for (i0 = j; i0 < fftLen; i0 += n1)
- {
- /* index calculation for the input as, */
- /* pSrc[i0 + 0], pSrc[i0 + fftLen/4], pSrc[i0 + fftLen/2], pSrc[i0 + 3fftLen/4] */
- i1 = i0 + n2;
- i2 = i1 + n2;
- i3 = i2 + n2;
+ /* xa - xc */
+ r2 = pSrc[(2u * i0)] - pSrc[(2u * i2)];
+
+ /* ya + yc */
+ s1 = pSrc[(2u * i0) + 1u] + pSrc[(2u * i2) + 1u];
- /* xa + xc */
- r1 = pSrc[(2u * i0)] + pSrc[(2u * i2)];
+ /* ya - yc */
+ s2 = pSrc[(2u * i0) + 1u] - pSrc[(2u * i2) + 1u];
- /* xa - xc */
- r2 = pSrc[(2u * i0)] - pSrc[(2u * i2)];
+ /* xb + xd */
+ t1 = pSrc[2u * i1] + pSrc[2u * i3];
- /* ya + yc */
- s1 = pSrc[(2u * i0) + 1u] + pSrc[(2u * i2) + 1u];
+ /* xa' = xa + xb + xc + xd */
+ pSrc[2u * i0] = r1 + t1;
- /* ya - yc */
- s2 = pSrc[(2u * i0) + 1u] - pSrc[(2u * i2) + 1u];
+ /* xa + xc -(xb + xd) */
+ r1 = r1 - t1;
- /* xb + xd */
- t1 = pSrc[2u * i1] + pSrc[2u * i3];
+ /* yb + yd */
+ t2 = pSrc[(2u * i1) + 1u] + pSrc[(2u * i3) + 1u];
- /* xa' = xa + xb + xc + xd */
- pSrc[2u * i0] = r1 + t1;
+ /* ya' = ya + yb + yc + yd */
+ pSrc[(2u * i0) + 1u] = s1 + t2;
+
+ /* (ya + yc) - (yb + yd) */
+ s1 = s1 - t2;
- /* xa + xc -(xb + xd) */
- r1 = r1 - t1;
+ /* (yb - yd) */
+ t1 = pSrc[(2u * i1) + 1u] - pSrc[(2u * i3) + 1u];
- /* yb + yd */
- t2 = pSrc[(2u * i1) + 1u] + pSrc[(2u * i3) + 1u];
+ /* (xb - xd) */
+ t2 = pSrc[2u * i1] - pSrc[2u * i3];
- /* ya' = ya + yb + yc + yd */
- pSrc[(2u * i0) + 1u] = s1 + t2;
+ /* xc' = (xa-xb+xc-xd)co2 - (ya-yb+yc-yd)(si2) */
+ pSrc[2u * i1] = (r1 * co2) - (s1 * si2);
- /* (ya + yc) - (yb + yd) */
- s1 = s1 - t2;
+ /* yc' = (ya-yb+yc-yd)co2 + (xa-xb+xc-xd)(si2) */
+ pSrc[(2u * i1) + 1u] = (s1 * co2) + (r1 * si2);
+
+ /* (xa - xc) - (yb - yd) */
+ r1 = r2 - t1;
- /* (yb - yd) */
- t1 = pSrc[(2u * i1) + 1u] - pSrc[(2u * i3) + 1u];
+ /* (xa - xc) + (yb - yd) */
+ r2 = r2 + t1;
- /* (xb - xd) */
- t2 = pSrc[2u * i1] - pSrc[2u * i3];
+ /* (ya - yc) + (xb - xd) */
+ s1 = s2 + t2;
- /* xc' = (xa-xb+xc-xd)co2 - (ya-yb+yc-yd)(si2) */
- pSrc[2u * i1] = (r1 * co2) - (s1 * si2);
+ /* (ya - yc) - (xb - xd) */
+ s2 = s2 - t2;
- /* yc' = (ya-yb+yc-yd)co2 + (xa-xb+xc-xd)(si2) */
- pSrc[(2u * i1) + 1u] = (s1 * co2) + (r1 * si2);
+ /* xb' = (xa+yb-xc-yd)co1 - (ya-xb-yc+xd)(si1) */
+ pSrc[2u * i2] = (r1 * co1) - (s1 * si1);
+
+ /* yb' = (ya-xb-yc+xd)co1 + (xa+yb-xc-yd)(si1) */
+ pSrc[(2u * i2) + 1u] = (s1 * co1) + (r1 * si1);
- /* (xa - xc) - (yb - yd) */
- r1 = r2 - t1;
-
- /* (xa - xc) + (yb - yd) */
- r2 = r2 + t1;
+ /* xd' = (xa-yb-xc+yd)co3 - (ya+xb-yc-xd)(si3) */
+ pSrc[2u * i3] = (r2 * co3) - (s2 * si3);
- /* (ya - yc) + (xb - xd) */
- s1 = s2 + t2;
-
- /* (ya - yc) - (xb - xd) */
- s2 = s2 - t2;
+ /* yd' = (ya+xb-yc-xd)co3 + (xa-yb-xc+yd)(si3) */
+ pSrc[(2u * i3) + 1u] = (s2 * co3) + (r2 * si3);
+
+ i0 += n1;
+ } while( i0 < fftLen);
+ j++;
+ } while(j <= (n2 - 1u));
+ twidCoefModifier <<= 2u;
+ }
+ /* Initializations of last stage */
+ n1 = n2;
+ n2 >>= 2u;
- /* xb' = (xa+yb-xc-yd)co1 - (ya-xb-yc+xd)(si1) */
- pSrc[2u * i2] = (r1 * co1) - (s1 * si1);
+ /* Calculations of last stage */
+ for (i0 = 0u; i0 <= (fftLen - n1); i0 += n1)
+ {
+ /* index calculation for the input as, */
+ /* pSrc[i0 + 0], pSrc[i0 + fftLen/4], pSrc[i0 + fftLen/2], pSrc[i0 + 3fftLen/4] */
+ i1 = i0 + n2;
+ i2 = i1 + n2;
+ i3 = i2 + n2;
- /* yb' = (ya-xb-yc+xd)co1 + (xa+yb-xc-yd)(si1) */
- pSrc[(2u * i2) + 1u] = (s1 * co1) + (r1 * si1);
-
- /* xd' = (xa-yb-xc+yd)co3 - (ya+xb-yc-xd)(si3) */
- pSrc[2u * i3] = (r2 * co3) - (s2 * si3);
+ /* Butterfly implementation */
+ /* xa + xc */
+ r1 = pSrc[2u * i0] + pSrc[2u * i2];
- /* yd' = (ya+xb-yc-xd)co3 + (xa-yb-xc+yd)(si3) */
- pSrc[(2u * i3) + 1u] = (s2 * co3) + (r2 * si3);
- }
- }
- twidCoefModifier <<= 2u;
- }
- /* Initializations of last stage */
- n1 = n2;
- n2 >>= 2u;
+ /* xa - xc */
+ r2 = pSrc[2u * i0] - pSrc[2u * i2];
+
+ /* ya + yc */
+ s1 = pSrc[(2u * i0) + 1u] + pSrc[(2u * i2) + 1u];
+
+ /* ya - yc */
+ s2 = pSrc[(2u * i0) + 1u] - pSrc[(2u * i2) + 1u];
+
+ /* xc + xd */
+ t1 = pSrc[2u * i1] + pSrc[2u * i3];
+
+ /* xa' = xa + xb + xc + xd */
+ pSrc[2u * i0] = (r1 + t1) * onebyfftLen;
- /* Calculations of last stage */
- for (i0 = 0u; i0 <= (fftLen - n1); i0 += n1)
- {
- /* index calculation for the input as, */
- /* pSrc[i0 + 0], pSrc[i0 + fftLen/4], pSrc[i0 + fftLen/2], pSrc[i0 + 3fftLen/4] */
- i1 = i0 + n2;
- i2 = i1 + n2;
- i3 = i2 + n2;
+ /* (xa + xb) - (xc + xd) */
+ r1 = r1 - t1;
+
+ /* yb + yd */
+ t2 = pSrc[(2u * i1) + 1u] + pSrc[(2u * i3) + 1u];
- /* Butterfly implementation */
- /* xa + xc */
- r1 = pSrc[2u * i0] + pSrc[2u * i2];
+ /* ya' = ya + yb + yc + yd */
+ pSrc[(2u * i0) + 1u] = (s1 + t2) * onebyfftLen;
+
+ /* (ya + yc) - (yb + yd) */
+ s1 = s1 - t2;
+
+ /* (yb-yd) */
+ t1 = pSrc[(2u * i1) + 1u] - pSrc[(2u * i3) + 1u];
- /* xa - xc */
- r2 = pSrc[2u * i0] - pSrc[2u * i2];
+ /* (xb-xd) */
+ t2 = pSrc[2u * i1] - pSrc[2u * i3];
- /* ya + yc */
- s1 = pSrc[(2u * i0) + 1u] + pSrc[(2u * i2) + 1u];
+ /* xc' = (xa-xb+xc-xd)co2 - (ya-yb+yc-yd)(si2) */
+ pSrc[2u * i1] = r1 * onebyfftLen;
- /* ya - yc */
- s2 = pSrc[(2u * i0) + 1u] - pSrc[(2u * i2) + 1u];
+ /* yc' = (ya-yb+yc-yd)co2 + (xa-xb+xc-xd)(si2) */
+ pSrc[(2u * i1) + 1u] = s1 * onebyfftLen;
- /* xc + xd */
- t1 = pSrc[2u * i1] + pSrc[2u * i3];
+ /* (xa - xc) - (yb-yd) */
+ r1 = r2 - t1;
- /* xa' = xa + xb + xc + xd */
- pSrc[2u * i0] = (r1 + t1) * onebyfftLen;
+ /* (xa - xc) + (yb-yd) */
+ r2 = r2 + t1;
- /* (xa + xb) - (xc + xd) */
- r1 = r1 - t1;
+ /* (ya - yc) + (xb-xd) */
+ s1 = s2 + t2;
- /* yb + yd */
- t2 = pSrc[(2u * i1) + 1u] + pSrc[(2u * i3) + 1u];
+ /* (ya - yc) - (xb-xd) */
+ s2 = s2 - t2;
- /* ya' = ya + yb + yc + yd */
- pSrc[(2u * i0) + 1u] = (s1 + t2) * onebyfftLen;
+ /* xb' = (xa+yb-xc-yd)co1 - (ya-xb-yc+xd)(si1) */
+ pSrc[2u * i2] = r1 * onebyfftLen;
- /* (ya + yc) - (yb + yd) */
- s1 = s1 - t2;
+ /* yb' = (ya-xb-yc+xd)co1 + (xa+yb-xc-yd)(si1) */
+ pSrc[(2u * i2) + 1u] = s1 * onebyfftLen;
- /* (yb-yd) */
- t1 = pSrc[(2u * i1) + 1u] - pSrc[(2u * i3) + 1u];
+ /* xd' = (xa-yb-xc+yd)co3 - (ya+xb-yc-xd)(si3) */
+ pSrc[2u * i3] = r2 * onebyfftLen;
- /* (xb-xd) */
- t2 = pSrc[2u * i1] - pSrc[2u * i3];
+ /* yd' = (ya+xb-yc-xd)co3 + (xa-yb-xc+yd)(si3) */
+ pSrc[(2u * i3) + 1u] = s2 * onebyfftLen;
+ }
- /* xc' = (xa-xb+xc-xd)co2 - (ya-yb+yc-yd)(si2) */
- pSrc[2u * i1] = r1 * onebyfftLen;
+#endif /* #ifndef ARM_MATH_CM0_FAMILY_FAMILY */
+}
- /* yc' = (ya-yb+yc-yd)co2 + (xa-xb+xc-xd)(si2) */
- pSrc[(2u * i1) + 1u] = s1 * onebyfftLen;
-
+/**
+* @addtogroup ComplexFFT
+* @{
+*/
- /* (xa - xc) - (yb-yd) */
- r1 = r2 - t1;
-
- /* (xa - xc) + (yb-yd) */
- r2 = r2 + t1;
+/**
+* @details
+* @brief Processing function for the floating-point Radix-4 CFFT/CIFFT.
+* @deprecated Do not use this function. It has been superceded by \ref arm_cfft_f32 and will be removed
+* in the future.
+* @param[in] *S points to an instance of the floating-point Radix-4 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.
+*/
- /* (ya - yc) + (xb-xd) */
- s1 = s2 + t2;
-
- /* (ya - yc) - (xb-xd) */
- s2 = s2 - t2;
+void arm_cfft_radix4_f32(
+const arm_cfft_radix4_instance_f32 * S,
+float32_t * pSrc)
+{
- /* xb' = (xa+yb-xc-yd)co1 - (ya-xb-yc+xd)(si1) */
- pSrc[2u * i2] = r1 * onebyfftLen;
-
- /* yb' = (ya-xb-yc+xd)co1 + (xa+yb-xc-yd)(si1) */
- pSrc[(2u * i2) + 1u] = s1 * onebyfftLen;
+ if(S->ifftFlag == 1u)
+ {
+ /* Complex IFFT radix-4 */
+ arm_radix4_butterfly_inverse_f32(pSrc, S->fftLen, S->pTwiddle,
+ S->twidCoefModifier, S->onebyfftLen);
+ }
+ else
+ {
+ /* Complex FFT radix-4 */
+ arm_radix4_butterfly_f32(pSrc, S->fftLen, S->pTwiddle,
+ S->twidCoefModifier);
+ }
- /* xd' = (xa-yb-xc+yd)co3 - (ya+xb-yc-xd)(si3) */
- pSrc[2u * i3] = r2 * onebyfftLen;
-
- /* yd' = (ya+xb-yc-xd)co3 + (xa-yb-xc+yd)(si3) */
- pSrc[(2u * i3) + 1u] = s2 * onebyfftLen;
- }
-
-#endif /* #ifndef ARM_MATH_CM0 */
+ if(S->bitReverseFlag == 1u)
+ {
+ /* Bit Reversal */
+ arm_bitreversal_f32(pSrc, S->fftLen, S->bitRevFactor, S->pBitRevTable);
+ }
}
+
+/**
+* @} end of ComplexFFT group
+*/
+