/* ----------------------------------------------------------------------
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* Copyright (C) 2010-2014 ARM Limited. All rights reserved.
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*
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* $Date: 19. March 2015
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* $Revision: V.1.4.5
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*
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* Project: CMSIS DSP Library
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* Title: arm_cfft_radix4_f32.c
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*
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* Description: Radix-4 Decimation in Frequency CFFT & CIFFT Floating point processing function
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*
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*
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* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* - Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* - Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* - Neither the name of ARM LIMITED nor the names of its contributors
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* may be used to endorse or promote products derived from this
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* software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
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* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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* -------------------------------------------------------------------- */
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#include "arm_math.h"
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extern void arm_bitreversal_f32(
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float32_t * pSrc,
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uint16_t fftSize,
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uint16_t bitRevFactor,
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uint16_t * pBitRevTab);
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/**
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* @ingroup groupTransforms
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*/
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/* ----------------------------------------------------------------------
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** Internal helper function used by the FFTs
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** ------------------------------------------------------------------- */
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/*
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* @brief Core function for the floating-point CFFT butterfly process.
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* @param[in, out] *pSrc points to the in-place buffer of floating-point data type.
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* @param[in] fftLen length of the FFT.
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* @param[in] *pCoef points to the twiddle coefficient buffer.
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* @param[in] twidCoefModifier twiddle coefficient modifier that supports different size FFTs with the same twiddle factor table.
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* @return none.
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*/
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void arm_radix4_butterfly_f32(
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float32_t * pSrc,
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uint16_t fftLen,
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float32_t * pCoef,
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uint16_t twidCoefModifier)
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{
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float32_t co1, co2, co3, si1, si2, si3;
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uint32_t ia1, ia2, ia3;
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uint32_t i0, i1, i2, i3;
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uint32_t n1, n2, j, k;
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#ifndef ARM_MATH_CM0_FAMILY_FAMILY
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/* Run the below code for Cortex-M4 and Cortex-M3 */
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float32_t xaIn, yaIn, xbIn, ybIn, xcIn, ycIn, xdIn, ydIn;
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float32_t Xaplusc, Xbplusd, Yaplusc, Ybplusd, Xaminusc, Xbminusd, Yaminusc,
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Ybminusd;
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float32_t Xb12C_out, Yb12C_out, Xc12C_out, Yc12C_out, Xd12C_out, Yd12C_out;
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float32_t Xb12_out, Yb12_out, Xc12_out, Yc12_out, Xd12_out, Yd12_out;
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float32_t *ptr1;
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float32_t p0,p1,p2,p3,p4,p5;
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float32_t a0,a1,a2,a3,a4,a5,a6,a7;
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/* Initializations for the first stage */
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n2 = fftLen;
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n1 = n2;
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/* n2 = fftLen/4 */
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n2 >>= 2u;
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i0 = 0u;
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ia1 = 0u;
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j = n2;
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/* Calculation of first stage */
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do
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{
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/* index calculation for the input as, */
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/* pSrc[i0 + 0], pSrc[i0 + fftLen/4], pSrc[i0 + fftLen/2], pSrc[i0 + 3fftLen/4] */
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i1 = i0 + n2;
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i2 = i1 + n2;
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i3 = i2 + n2;
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xaIn = pSrc[(2u * i0)];
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yaIn = pSrc[(2u * i0) + 1u];
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xbIn = pSrc[(2u * i1)];
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ybIn = pSrc[(2u * i1) + 1u];
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xcIn = pSrc[(2u * i2)];
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ycIn = pSrc[(2u * i2) + 1u];
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xdIn = pSrc[(2u * i3)];
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ydIn = pSrc[(2u * i3) + 1u];
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/* xa + xc */
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Xaplusc = xaIn + xcIn;
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/* xb + xd */
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Xbplusd = xbIn + xdIn;
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/* ya + yc */
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Yaplusc = yaIn + ycIn;
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/* yb + yd */
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Ybplusd = ybIn + ydIn;
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/* index calculation for the coefficients */
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ia2 = ia1 + ia1;
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co2 = pCoef[ia2 * 2u];
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si2 = pCoef[(ia2 * 2u) + 1u];
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/* xa - xc */
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Xaminusc = xaIn - xcIn;
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/* xb - xd */
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Xbminusd = xbIn - xdIn;
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/* ya - yc */
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Yaminusc = yaIn - ycIn;
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/* yb - yd */
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Ybminusd = ybIn - ydIn;
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/* xa' = xa + xb + xc + xd */
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pSrc[(2u * i0)] = Xaplusc + Xbplusd;
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/* ya' = ya + yb + yc + yd */
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pSrc[(2u * i0) + 1u] = Yaplusc + Ybplusd;
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/* (xa - xc) + (yb - yd) */
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Xb12C_out = (Xaminusc + Ybminusd);
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/* (ya - yc) + (xb - xd) */
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Yb12C_out = (Yaminusc - Xbminusd);
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/* (xa + xc) - (xb + xd) */
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Xc12C_out = (Xaplusc - Xbplusd);
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/* (ya + yc) - (yb + yd) */
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Yc12C_out = (Yaplusc - Ybplusd);
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/* (xa - xc) - (yb - yd) */
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Xd12C_out = (Xaminusc - Ybminusd);
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/* (ya - yc) + (xb - xd) */
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Yd12C_out = (Xbminusd + Yaminusc);
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co1 = pCoef[ia1 * 2u];
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si1 = pCoef[(ia1 * 2u) + 1u];
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/* index calculation for the coefficients */
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ia3 = ia2 + ia1;
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co3 = pCoef[ia3 * 2u];
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si3 = pCoef[(ia3 * 2u) + 1u];
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Xb12_out = Xb12C_out * co1;
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Yb12_out = Yb12C_out * co1;
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Xc12_out = Xc12C_out * co2;
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Yc12_out = Yc12C_out * co2;
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Xd12_out = Xd12C_out * co3;
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Yd12_out = Yd12C_out * co3;
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/* xb' = (xa+yb-xc-yd)co1 - (ya-xb-yc+xd)(si1) */
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//Xb12_out -= Yb12C_out * si1;
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p0 = Yb12C_out * si1;
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/* yb' = (ya-xb-yc+xd)co1 + (xa+yb-xc-yd)(si1) */
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//Yb12_out += Xb12C_out * si1;
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p1 = Xb12C_out * si1;
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/* xc' = (xa-xb+xc-xd)co2 - (ya-yb+yc-yd)(si2) */
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//Xc12_out -= Yc12C_out * si2;
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p2 = Yc12C_out * si2;
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/* yc' = (ya-yb+yc-yd)co2 + (xa-xb+xc-xd)(si2) */
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//Yc12_out += Xc12C_out * si2;
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p3 = Xc12C_out * si2;
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/* xd' = (xa-yb-xc+yd)co3 - (ya+xb-yc-xd)(si3) */
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//Xd12_out -= Yd12C_out * si3;
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p4 = Yd12C_out * si3;
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/* yd' = (ya+xb-yc-xd)co3 + (xa-yb-xc+yd)(si3) */
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//Yd12_out += Xd12C_out * si3;
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p5 = Xd12C_out * si3;
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Xb12_out += p0;
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Yb12_out -= p1;
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Xc12_out += p2;
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Yc12_out -= p3;
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Xd12_out += p4;
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Yd12_out -= p5;
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/* xc' = (xa-xb+xc-xd)co2 + (ya-yb+yc-yd)(si2) */
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pSrc[2u * i1] = Xc12_out;
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/* yc' = (ya-yb+yc-yd)co2 - (xa-xb+xc-xd)(si2) */
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pSrc[(2u * i1) + 1u] = Yc12_out;
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/* xb' = (xa+yb-xc-yd)co1 + (ya-xb-yc+xd)(si1) */
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pSrc[2u * i2] = Xb12_out;
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/* yb' = (ya-xb-yc+xd)co1 - (xa+yb-xc-yd)(si1) */
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pSrc[(2u * i2) + 1u] = Yb12_out;
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/* xd' = (xa-yb-xc+yd)co3 + (ya+xb-yc-xd)(si3) */
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pSrc[2u * i3] = Xd12_out;
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/* yd' = (ya+xb-yc-xd)co3 - (xa-yb-xc+yd)(si3) */
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pSrc[(2u * i3) + 1u] = Yd12_out;
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/* Twiddle coefficients index modifier */
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ia1 += twidCoefModifier;
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/* Updating input index */
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i0++;
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}
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while(--j);
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twidCoefModifier <<= 2u;
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/* Calculation of second stage to excluding last stage */
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for (k = fftLen >> 2u; k > 4u; k >>= 2u)
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{
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/* Initializations for the first stage */
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n1 = n2;
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n2 >>= 2u;
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ia1 = 0u;
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/* Calculation of first stage */
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j = 0;
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do
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{
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/* index calculation for the coefficients */
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ia2 = ia1 + ia1;
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ia3 = ia2 + ia1;
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co1 = pCoef[ia1 * 2u];
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si1 = pCoef[(ia1 * 2u) + 1u];
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co2 = pCoef[ia2 * 2u];
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si2 = pCoef[(ia2 * 2u) + 1u];
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co3 = pCoef[ia3 * 2u];
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si3 = pCoef[(ia3 * 2u) + 1u];
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/* Twiddle coefficients index modifier */
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ia1 += twidCoefModifier;
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i0 = j;
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do
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{
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/* index calculation for the input as, */
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/* pSrc[i0 + 0], pSrc[i0 + fftLen/4], pSrc[i0 + fftLen/2], pSrc[i0 + 3fftLen/4] */
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i1 = i0 + n2;
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i2 = i1 + n2;
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i3 = i2 + n2;
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xaIn = pSrc[(2u * i0)];
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yaIn = pSrc[(2u * i0) + 1u];
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xbIn = pSrc[(2u * i1)];
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ybIn = pSrc[(2u * i1) + 1u];
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xcIn = pSrc[(2u * i2)];
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ycIn = pSrc[(2u * i2) + 1u];
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xdIn = pSrc[(2u * i3)];
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ydIn = pSrc[(2u * i3) + 1u];
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/* xa - xc */
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Xaminusc = xaIn - xcIn;
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/* (xb - xd) */
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Xbminusd = xbIn - xdIn;
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/* ya - yc */
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Yaminusc = yaIn - ycIn;
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/* (yb - yd) */
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Ybminusd = ybIn - ydIn;
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/* xa + xc */
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Xaplusc = xaIn + xcIn;
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/* xb + xd */
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Xbplusd = xbIn + xdIn;
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/* ya + yc */
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Yaplusc = yaIn + ycIn;
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/* yb + yd */
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Ybplusd = ybIn + ydIn;
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/* (xa - xc) + (yb - yd) */
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Xb12C_out = (Xaminusc + Ybminusd);
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/* (ya - yc) - (xb - xd) */
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Yb12C_out = (Yaminusc - Xbminusd);
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/* xa + xc -(xb + xd) */
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Xc12C_out = (Xaplusc - Xbplusd);
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/* (ya + yc) - (yb + yd) */
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Yc12C_out = (Yaplusc - Ybplusd);
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/* (xa - xc) - (yb - yd) */
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Xd12C_out = (Xaminusc - Ybminusd);
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/* (ya - yc) + (xb - xd) */
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Yd12C_out = (Xbminusd + Yaminusc);
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pSrc[(2u * i0)] = Xaplusc + Xbplusd;
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pSrc[(2u * i0) + 1u] = Yaplusc + Ybplusd;
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Xb12_out = Xb12C_out * co1;
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Yb12_out = Yb12C_out * co1;
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Xc12_out = Xc12C_out * co2;
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Yc12_out = Yc12C_out * co2;
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Xd12_out = Xd12C_out * co3;
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Yd12_out = Yd12C_out * co3;
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/* xb' = (xa+yb-xc-yd)co1 - (ya-xb-yc+xd)(si1) */
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//Xb12_out -= Yb12C_out * si1;
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p0 = Yb12C_out * si1;
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/* yb' = (ya-xb-yc+xd)co1 + (xa+yb-xc-yd)(si1) */
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//Yb12_out += Xb12C_out * si1;
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p1 = Xb12C_out * si1;
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/* xc' = (xa-xb+xc-xd)co2 - (ya-yb+yc-yd)(si2) */
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//Xc12_out -= Yc12C_out * si2;
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p2 = Yc12C_out * si2;
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/* yc' = (ya-yb+yc-yd)co2 + (xa-xb+xc-xd)(si2) */
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//Yc12_out += Xc12C_out * si2;
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p3 = Xc12C_out * si2;
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/* xd' = (xa-yb-xc+yd)co3 - (ya+xb-yc-xd)(si3) */
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//Xd12_out -= Yd12C_out * si3;
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p4 = Yd12C_out * si3;
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/* yd' = (ya+xb-yc-xd)co3 + (xa-yb-xc+yd)(si3) */
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//Yd12_out += Xd12C_out * si3;
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p5 = Xd12C_out * si3;
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Xb12_out += p0;
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Yb12_out -= p1;
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Xc12_out += p2;
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Yc12_out -= p3;
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Xd12_out += p4;
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Yd12_out -= p5;
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/* xc' = (xa-xb+xc-xd)co2 + (ya-yb+yc-yd)(si2) */
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pSrc[2u * i1] = Xc12_out;
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/* yc' = (ya-yb+yc-yd)co2 - (xa-xb+xc-xd)(si2) */
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pSrc[(2u * i1) + 1u] = Yc12_out;
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/* xb' = (xa+yb-xc-yd)co1 + (ya-xb-yc+xd)(si1) */
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pSrc[2u * i2] = Xb12_out;
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/* yb' = (ya-xb-yc+xd)co1 - (xa+yb-xc-yd)(si1) */
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pSrc[(2u * i2) + 1u] = Yb12_out;
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/* xd' = (xa-yb-xc+yd)co3 + (ya+xb-yc-xd)(si3) */
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pSrc[2u * i3] = Xd12_out;
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/* yd' = (ya+xb-yc-xd)co3 - (xa-yb-xc+yd)(si3) */
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pSrc[(2u * i3) + 1u] = Yd12_out;
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i0 += n1;
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} while(i0 < fftLen);
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j++;
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} while(j <= (n2 - 1u));
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twidCoefModifier <<= 2u;
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}
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j = fftLen >> 2;
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ptr1 = &pSrc[0];
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/* Calculations of last stage */
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do
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{
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xaIn = ptr1[0];
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yaIn = ptr1[1];
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xbIn = ptr1[2];
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ybIn = ptr1[3];
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xcIn = ptr1[4];
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ycIn = ptr1[5];
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xdIn = ptr1[6];
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ydIn = ptr1[7];
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/* xa + xc */
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Xaplusc = xaIn + xcIn;
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/* xa - xc */
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Xaminusc = xaIn - xcIn;
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/* ya + yc */
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Yaplusc = yaIn + ycIn;
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/* ya - yc */
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Yaminusc = yaIn - ycIn;
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/* xb + xd */
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Xbplusd = xbIn + xdIn;
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/* yb + yd */
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Ybplusd = ybIn + ydIn;
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/* (xb-xd) */
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Xbminusd = xbIn - xdIn;
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/* (yb-yd) */
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Ybminusd = ybIn - ydIn;
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/* xa' = xa + xb + xc + xd */
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a0 = (Xaplusc + Xbplusd);
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/* ya' = ya + yb + yc + yd */
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a1 = (Yaplusc + Ybplusd);
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/* xc' = (xa-xb+xc-xd) */
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a2 = (Xaplusc - Xbplusd);
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/* yc' = (ya-yb+yc-yd) */
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a3 = (Yaplusc - Ybplusd);
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/* xb' = (xa+yb-xc-yd) */
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a4 = (Xaminusc + Ybminusd);
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/* yb' = (ya-xb-yc+xd) */
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a5 = (Yaminusc - Xbminusd);
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/* xd' = (xa-yb-xc+yd)) */
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a6 = (Xaminusc - Ybminusd);
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/* yd' = (ya+xb-yc-xd) */
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a7 = (Xbminusd + Yaminusc);
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ptr1[0] = a0;
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ptr1[1] = a1;
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ptr1[2] = a2;
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ptr1[3] = a3;
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ptr1[4] = a4;
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ptr1[5] = a5;
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ptr1[6] = a6;
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ptr1[7] = a7;
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/* increment pointer by 8 */
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ptr1 += 8u;
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} while(--j);
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#else
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float32_t t1, t2, r1, r2, s1, s2;
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/* Run the below code for Cortex-M0 */
|
|
/* Initializations for the fft calculation */
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n2 = fftLen;
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n1 = n2;
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for (k = fftLen; k > 1u; k >>= 2u)
|
{
|
/* Initializations for the fft calculation */
|
n1 = n2;
|
n2 >>= 2u;
|
ia1 = 0u;
|
|
/* FFT Calculation */
|
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;
|
|
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)];
|
|
/* 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];
|
|
/* xb + xd */
|
t1 = pSrc[2u * i1] + pSrc[2u * i3];
|
|
/* xa' = xa + xb + xc + xd */
|
pSrc[2u * i0] = r1 + t1;
|
|
/* xa + xc -(xb + xd) */
|
r1 = r1 - t1;
|
|
/* yb + yd */
|
t2 = pSrc[(2u * i1) + 1u] + pSrc[(2u * i3) + 1u];
|
|
/* ya' = ya + yb + yc + yd */
|
pSrc[(2u * i0) + 1u] = s1 + t2;
|
|
/* (ya + yc) - (yb + yd) */
|
s1 = s1 - t2;
|
|
/* (yb - yd) */
|
t1 = pSrc[(2u * i1) + 1u] - pSrc[(2u * i3) + 1u];
|
|
/* (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);
|
|
/* 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) */
|
r2 = r2 - t1;
|
|
/* (ya - yc) - (xb - xd) */
|
s1 = 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);
|
|
/* 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);
|
|
/* 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_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.
|
*/
|
|
void arm_radix4_butterfly_inverse_f32(
|
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;
|
|
#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 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;
|
|
/* 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];
|
|
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;
|
|
/* 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;
|
|
/* (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];
|
|
/* 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;
|
|
/* Updating input index */
|
i0 = i0 + 1u;
|
|
} while(--j);
|
|
twidCoefModifier <<= 2u;
|
|
/* 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;
|
|
/* 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;
|
|
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];
|
|
xdIn = pSrc[(2u * i3)];
|
ydIn = pSrc[(2u * i3) + 1u];
|
|
/* xa - xc */
|
Xaminusc = xaIn - xcIn;
|
/* (xb - xd) */
|
Xbminusd = xbIn - xdIn;
|
/* ya - yc */
|
Yaminusc = yaIn - ycIn;
|
/* (yb - yd) */
|
Ybminusd = ybIn - ydIn;
|
|
/* xa + xc */
|
Xaplusc = xaIn + xcIn;
|
/* xb + xd */
|
Xbplusd = xbIn + xdIn;
|
/* ya + yc */
|
Yaplusc = yaIn + ycIn;
|
/* yb + yd */
|
Ybplusd = ybIn + ydIn;
|
|
/* (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);
|
|
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;
|
|
/* 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;
|
|
i0 += n1;
|
} while(i0 < fftLen);
|
j++;
|
} while(j <= (n2 - 1u));
|
twidCoefModifier <<= 2u;
|
}
|
/* Initializations of last stage */
|
|
j = fftLen >> 2;
|
ptr1 = &pSrc[0];
|
|
/* 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];
|
|
/* Butterfly implementation */
|
/* xa + xc */
|
Xaplusc = xaIn + xcIn;
|
|
/* xa - xc */
|
Xaminusc = xaIn - xcIn;
|
|
/* ya + yc */
|
Yaplusc = yaIn + ycIn;
|
|
/* ya - yc */
|
Yaminusc = yaIn - ycIn;
|
|
/* xb + xd */
|
Xbplusd = xbIn + xdIn;
|
|
/* yb + yd */
|
Ybplusd = ybIn + ydIn;
|
|
/* (xb-xd) */
|
Xbminusd = xbIn - xdIn;
|
|
/* (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;
|
|
/* increment source pointer by 8 for next calculations */
|
ptr1 = ptr1 + 8u;
|
|
} while(--j);
|
|
#else
|
|
float32_t t1, t2, r1, r2, s1, s2;
|
|
/* Run the below code for Cortex-M0 */
|
|
/* 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 */
|
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;
|
|
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)];
|
|
/* 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];
|
|
/* xb + xd */
|
t1 = pSrc[2u * i1] + pSrc[2u * i3];
|
|
/* xa' = xa + xb + xc + xd */
|
pSrc[2u * i0] = r1 + t1;
|
|
/* xa + xc -(xb + xd) */
|
r1 = r1 - t1;
|
|
/* yb + yd */
|
t2 = pSrc[(2u * i1) + 1u] + pSrc[(2u * i3) + 1u];
|
|
/* ya' = ya + yb + yc + yd */
|
pSrc[(2u * i0) + 1u] = s1 + t2;
|
|
/* (ya + yc) - (yb + yd) */
|
s1 = s1 - t2;
|
|
/* (yb - yd) */
|
t1 = pSrc[(2u * i1) + 1u] - pSrc[(2u * i3) + 1u];
|
|
/* (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);
|
|
/* 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) */
|
r2 = r2 + t1;
|
|
/* (ya - yc) + (xb - xd) */
|
s1 = 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);
|
|
/* 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);
|
|
/* 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;
|
|
/* 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;
|
|
/* Butterfly implementation */
|
/* xa + xc */
|
r1 = pSrc[2u * i0] + pSrc[2u * i2];
|
|
/* 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;
|
|
/* (xa + xb) - (xc + xd) */
|
r1 = r1 - t1;
|
|
/* yb + yd */
|
t2 = pSrc[(2u * i1) + 1u] + pSrc[(2u * i3) + 1u];
|
|
/* 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];
|
|
/* (xb-xd) */
|
t2 = pSrc[2u * i1] - pSrc[2u * i3];
|
|
/* xc' = (xa-xb+xc-xd)co2 - (ya-yb+yc-yd)(si2) */
|
pSrc[2u * i1] = r1 * onebyfftLen;
|
|
/* yc' = (ya-yb+yc-yd)co2 + (xa-xb+xc-xd)(si2) */
|
pSrc[(2u * i1) + 1u] = s1 * onebyfftLen;
|
|
/* (xa - xc) - (yb-yd) */
|
r1 = r2 - t1;
|
|
/* (xa - xc) + (yb-yd) */
|
r2 = r2 + t1;
|
|
/* (ya - yc) + (xb-xd) */
|
s1 = s2 + t2;
|
|
/* (ya - yc) - (xb-xd) */
|
s2 = s2 - t2;
|
|
/* 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;
|
|
/* 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_FAMILY_FAMILY */
|
}
|
|
/**
|
* @addtogroup ComplexFFT
|
* @{
|
*/
|
|
/**
|
* @details
|
* @brief Processing function for the floating-point Radix-4 CFFT/CIFFT.
|
* @deprecated Do not use this function. It has been superseded 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.
|
*/
|
|
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 ComplexFFT group
|
*/
|
