/* ----------------------------------------------------------------------
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* Project: CMSIS DSP Library
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* Title: arm_cfft_radix2_q15.c
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* Description: Radix-2 Decimation in Frequency CFFT & CIFFT Fixed point processing function
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*
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* $Date: 27. January 2017
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* $Revision: V.1.5.1
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*
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* Target Processor: Cortex-M cores
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* -------------------------------------------------------------------- */
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/*
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* Copyright (C) 2010-2017 ARM Limited or its affiliates. All rights reserved.
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*
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* SPDX-License-Identifier: Apache-2.0
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*
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* Licensed under the Apache License, Version 2.0 (the License); you may
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* not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an AS IS BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include "arm_math.h"
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void arm_radix2_butterfly_q15(
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q15_t * pSrc,
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uint32_t fftLen,
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q15_t * pCoef,
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uint16_t twidCoefModifier);
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void arm_radix2_butterfly_inverse_q15(
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q15_t * pSrc,
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uint32_t fftLen,
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q15_t * pCoef,
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uint16_t twidCoefModifier);
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void arm_bitreversal_q15(
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q15_t * pSrc,
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uint32_t fftLen,
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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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* @addtogroup ComplexFFT
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* @{
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*/
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/**
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* @details
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* @brief Processing function for the fixed-point CFFT/CIFFT.
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* @deprecated Do not use this function. It has been superseded by \ref arm_cfft_q15 and will be removed
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* @param[in] *S points to an instance of the fixed-point CFFT/CIFFT structure.
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* @param[in, out] *pSrc points to the complex data buffer of size <code>2*fftLen</code>. Processing occurs in-place.
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* @return none.
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*/
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void arm_cfft_radix2_q15(
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const arm_cfft_radix2_instance_q15 * S,
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q15_t * pSrc)
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{
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if (S->ifftFlag == 1U)
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{
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arm_radix2_butterfly_inverse_q15(pSrc, S->fftLen,
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S->pTwiddle, S->twidCoefModifier);
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}
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else
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{
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arm_radix2_butterfly_q15(pSrc, S->fftLen,
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S->pTwiddle, S->twidCoefModifier);
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}
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arm_bitreversal_q15(pSrc, S->fftLen, S->bitRevFactor, S->pBitRevTable);
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}
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/**
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* @} end of ComplexFFT group
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*/
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void arm_radix2_butterfly_q15(
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q15_t * pSrc,
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uint32_t fftLen,
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q15_t * pCoef,
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uint16_t twidCoefModifier)
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{
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#if defined (ARM_MATH_DSP)
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unsigned i, j, k, l;
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unsigned n1, n2, ia;
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q15_t in;
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q31_t T, S, R;
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q31_t coeff, out1, out2;
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//N = fftLen;
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n2 = fftLen;
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n1 = n2;
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n2 = n2 >> 1;
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ia = 0;
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// loop for groups
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for (i = 0; i < n2; i++)
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{
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coeff = _SIMD32_OFFSET(pCoef + (ia * 2U));
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ia = ia + twidCoefModifier;
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l = i + n2;
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T = _SIMD32_OFFSET(pSrc + (2 * i));
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in = ((int16_t) (T & 0xFFFF)) >> 1;
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T = ((T >> 1) & 0xFFFF0000) | (in & 0xFFFF);
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S = _SIMD32_OFFSET(pSrc + (2 * l));
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in = ((int16_t) (S & 0xFFFF)) >> 1;
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S = ((S >> 1) & 0xFFFF0000) | (in & 0xFFFF);
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R = __QSUB16(T, S);
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_SIMD32_OFFSET(pSrc + (2 * i)) = __SHADD16(T, S);
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#ifndef ARM_MATH_BIG_ENDIAN
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out1 = __SMUAD(coeff, R) >> 16;
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out2 = __SMUSDX(coeff, R);
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#else
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out1 = __SMUSDX(R, coeff) >> 16U;
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out2 = __SMUAD(coeff, R);
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#endif // #ifndef ARM_MATH_BIG_ENDIAN
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_SIMD32_OFFSET(pSrc + (2U * l)) =
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(q31_t) ((out2) & 0xFFFF0000) | (out1 & 0x0000FFFF);
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coeff = _SIMD32_OFFSET(pCoef + (ia * 2U));
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ia = ia + twidCoefModifier;
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// loop for butterfly
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i++;
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l++;
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T = _SIMD32_OFFSET(pSrc + (2 * i));
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in = ((int16_t) (T & 0xFFFF)) >> 1;
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T = ((T >> 1) & 0xFFFF0000) | (in & 0xFFFF);
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S = _SIMD32_OFFSET(pSrc + (2 * l));
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in = ((int16_t) (S & 0xFFFF)) >> 1;
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S = ((S >> 1) & 0xFFFF0000) | (in & 0xFFFF);
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R = __QSUB16(T, S);
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_SIMD32_OFFSET(pSrc + (2 * i)) = __SHADD16(T, S);
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#ifndef ARM_MATH_BIG_ENDIAN
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out1 = __SMUAD(coeff, R) >> 16;
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out2 = __SMUSDX(coeff, R);
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#else
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out1 = __SMUSDX(R, coeff) >> 16U;
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out2 = __SMUAD(coeff, R);
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#endif // #ifndef ARM_MATH_BIG_ENDIAN
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_SIMD32_OFFSET(pSrc + (2U * l)) =
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(q31_t) ((out2) & 0xFFFF0000) | (out1 & 0x0000FFFF);
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} // groups loop end
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twidCoefModifier = twidCoefModifier << 1U;
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// loop for stage
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for (k = fftLen / 2; k > 2; k = k >> 1)
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{
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n1 = n2;
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n2 = n2 >> 1;
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ia = 0;
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// loop for groups
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for (j = 0; j < n2; j++)
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{
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coeff = _SIMD32_OFFSET(pCoef + (ia * 2U));
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ia = ia + twidCoefModifier;
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// loop for butterfly
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for (i = j; i < fftLen; i += n1)
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{
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l = i + n2;
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T = _SIMD32_OFFSET(pSrc + (2 * i));
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S = _SIMD32_OFFSET(pSrc + (2 * l));
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R = __QSUB16(T, S);
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_SIMD32_OFFSET(pSrc + (2 * i)) = __SHADD16(T, S);
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#ifndef ARM_MATH_BIG_ENDIAN
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out1 = __SMUAD(coeff, R) >> 16;
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out2 = __SMUSDX(coeff, R);
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#else
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out1 = __SMUSDX(R, coeff) >> 16U;
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out2 = __SMUAD(coeff, R);
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#endif // #ifndef ARM_MATH_BIG_ENDIAN
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_SIMD32_OFFSET(pSrc + (2U * l)) =
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(q31_t) ((out2) & 0xFFFF0000) | (out1 & 0x0000FFFF);
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i += n1;
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l = i + n2;
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T = _SIMD32_OFFSET(pSrc + (2 * i));
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S = _SIMD32_OFFSET(pSrc + (2 * l));
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R = __QSUB16(T, S);
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_SIMD32_OFFSET(pSrc + (2 * i)) = __SHADD16(T, S);
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#ifndef ARM_MATH_BIG_ENDIAN
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out1 = __SMUAD(coeff, R) >> 16;
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out2 = __SMUSDX(coeff, R);
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#else
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out1 = __SMUSDX(R, coeff) >> 16U;
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out2 = __SMUAD(coeff, R);
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#endif // #ifndef ARM_MATH_BIG_ENDIAN
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_SIMD32_OFFSET(pSrc + (2U * l)) =
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(q31_t) ((out2) & 0xFFFF0000) | (out1 & 0x0000FFFF);
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} // butterfly loop end
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} // groups loop end
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twidCoefModifier = twidCoefModifier << 1U;
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} // stages loop end
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n1 = n2;
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n2 = n2 >> 1;
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ia = 0;
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coeff = _SIMD32_OFFSET(pCoef + (ia * 2U));
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ia = ia + twidCoefModifier;
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// loop for butterfly
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for (i = 0; i < fftLen; i += n1)
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{
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l = i + n2;
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T = _SIMD32_OFFSET(pSrc + (2 * i));
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S = _SIMD32_OFFSET(pSrc + (2 * l));
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R = __QSUB16(T, S);
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_SIMD32_OFFSET(pSrc + (2 * i)) = __QADD16(T, S);
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_SIMD32_OFFSET(pSrc + (2U * l)) = R;
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i += n1;
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l = i + n2;
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T = _SIMD32_OFFSET(pSrc + (2 * i));
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S = _SIMD32_OFFSET(pSrc + (2 * l));
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R = __QSUB16(T, S);
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_SIMD32_OFFSET(pSrc + (2 * i)) = __QADD16(T, S);
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_SIMD32_OFFSET(pSrc + (2U * l)) = R;
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} // groups loop end
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#else
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unsigned i, j, k, l;
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unsigned n1, n2, ia;
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q15_t xt, yt, cosVal, sinVal;
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//N = fftLen;
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n2 = fftLen;
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n1 = n2;
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n2 = n2 >> 1;
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ia = 0;
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// loop for groups
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for (j = 0; j < n2; j++)
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{
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cosVal = pCoef[ia * 2];
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sinVal = pCoef[(ia * 2) + 1];
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ia = ia + twidCoefModifier;
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// loop for butterfly
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for (i = j; i < fftLen; i += n1)
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{
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l = i + n2;
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xt = (pSrc[2 * i] >> 1U) - (pSrc[2 * l] >> 1U);
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pSrc[2 * i] = ((pSrc[2 * i] >> 1U) + (pSrc[2 * l] >> 1U)) >> 1U;
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yt = (pSrc[2 * i + 1] >> 1U) - (pSrc[2 * l + 1] >> 1U);
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pSrc[2 * i + 1] =
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((pSrc[2 * l + 1] >> 1U) + (pSrc[2 * i + 1] >> 1U)) >> 1U;
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pSrc[2U * l] = (((int16_t) (((q31_t) xt * cosVal) >> 16)) +
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((int16_t) (((q31_t) yt * sinVal) >> 16)));
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pSrc[2U * l + 1U] = (((int16_t) (((q31_t) yt * cosVal) >> 16)) -
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((int16_t) (((q31_t) xt * sinVal) >> 16)));
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} // butterfly loop end
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} // groups loop end
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twidCoefModifier = twidCoefModifier << 1U;
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// loop for stage
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for (k = fftLen / 2; k > 2; k = k >> 1)
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{
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n1 = n2;
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n2 = n2 >> 1;
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ia = 0;
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// loop for groups
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for (j = 0; j < n2; j++)
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{
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cosVal = pCoef[ia * 2];
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sinVal = pCoef[(ia * 2) + 1];
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ia = ia + twidCoefModifier;
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// loop for butterfly
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for (i = j; i < fftLen; i += n1)
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{
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l = i + n2;
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xt = pSrc[2 * i] - pSrc[2 * l];
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pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]) >> 1U;
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yt = pSrc[2 * i + 1] - pSrc[2 * l + 1];
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pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]) >> 1U;
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pSrc[2U * l] = (((int16_t) (((q31_t) xt * cosVal) >> 16)) +
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((int16_t) (((q31_t) yt * sinVal) >> 16)));
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pSrc[2U * l + 1U] = (((int16_t) (((q31_t) yt * cosVal) >> 16)) -
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((int16_t) (((q31_t) xt * sinVal) >> 16)));
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} // butterfly loop end
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} // groups loop end
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twidCoefModifier = twidCoefModifier << 1U;
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} // stages loop end
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n1 = n2;
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n2 = n2 >> 1;
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ia = 0;
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// loop for groups
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for (j = 0; j < n2; j++)
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{
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cosVal = pCoef[ia * 2];
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sinVal = pCoef[(ia * 2) + 1];
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ia = ia + twidCoefModifier;
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// loop for butterfly
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for (i = j; i < fftLen; i += n1)
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{
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l = i + n2;
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xt = pSrc[2 * i] - pSrc[2 * l];
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pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]);
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yt = pSrc[2 * i + 1] - pSrc[2 * l + 1];
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pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]);
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pSrc[2U * l] = xt;
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pSrc[2U * l + 1U] = yt;
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} // butterfly loop end
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} // groups loop end
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twidCoefModifier = twidCoefModifier << 1U;
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#endif // #if defined (ARM_MATH_DSP)
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}
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void arm_radix2_butterfly_inverse_q15(
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q15_t * pSrc,
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uint32_t fftLen,
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q15_t * pCoef,
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uint16_t twidCoefModifier)
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{
|
#if defined (ARM_MATH_DSP)
|
|
unsigned i, j, k, l;
|
unsigned n1, n2, ia;
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q15_t in;
|
q31_t T, S, R;
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q31_t coeff, out1, out2;
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//N = fftLen;
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n2 = fftLen;
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n1 = n2;
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n2 = n2 >> 1;
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ia = 0;
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// loop for groups
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for (i = 0; i < n2; i++)
|
{
|
coeff = _SIMD32_OFFSET(pCoef + (ia * 2U));
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ia = ia + twidCoefModifier;
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l = i + n2;
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T = _SIMD32_OFFSET(pSrc + (2 * i));
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in = ((int16_t) (T & 0xFFFF)) >> 1;
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T = ((T >> 1) & 0xFFFF0000) | (in & 0xFFFF);
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S = _SIMD32_OFFSET(pSrc + (2 * l));
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in = ((int16_t) (S & 0xFFFF)) >> 1;
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S = ((S >> 1) & 0xFFFF0000) | (in & 0xFFFF);
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R = __QSUB16(T, S);
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_SIMD32_OFFSET(pSrc + (2 * i)) = __SHADD16(T, S);
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#ifndef ARM_MATH_BIG_ENDIAN
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out1 = __SMUSD(coeff, R) >> 16;
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out2 = __SMUADX(coeff, R);
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#else
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out1 = __SMUADX(R, coeff) >> 16U;
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out2 = __SMUSD(__QSUB(0, coeff), R);
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#endif // #ifndef ARM_MATH_BIG_ENDIAN
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_SIMD32_OFFSET(pSrc + (2U * l)) =
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(q31_t) ((out2) & 0xFFFF0000) | (out1 & 0x0000FFFF);
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coeff = _SIMD32_OFFSET(pCoef + (ia * 2U));
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ia = ia + twidCoefModifier;
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// loop for butterfly
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i++;
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l++;
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T = _SIMD32_OFFSET(pSrc + (2 * i));
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in = ((int16_t) (T & 0xFFFF)) >> 1;
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T = ((T >> 1) & 0xFFFF0000) | (in & 0xFFFF);
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S = _SIMD32_OFFSET(pSrc + (2 * l));
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in = ((int16_t) (S & 0xFFFF)) >> 1;
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S = ((S >> 1) & 0xFFFF0000) | (in & 0xFFFF);
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R = __QSUB16(T, S);
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_SIMD32_OFFSET(pSrc + (2 * i)) = __SHADD16(T, S);
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#ifndef ARM_MATH_BIG_ENDIAN
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out1 = __SMUSD(coeff, R) >> 16;
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out2 = __SMUADX(coeff, R);
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#else
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out1 = __SMUADX(R, coeff) >> 16U;
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out2 = __SMUSD(__QSUB(0, coeff), R);
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#endif // #ifndef ARM_MATH_BIG_ENDIAN
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_SIMD32_OFFSET(pSrc + (2U * l)) =
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(q31_t) ((out2) & 0xFFFF0000) | (out1 & 0x0000FFFF);
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} // groups loop end
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twidCoefModifier = twidCoefModifier << 1U;
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// loop for stage
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for (k = fftLen / 2; k > 2; k = k >> 1)
|
{
|
n1 = n2;
|
n2 = n2 >> 1;
|
ia = 0;
|
|
// loop for groups
|
for (j = 0; j < n2; j++)
|
{
|
coeff = _SIMD32_OFFSET(pCoef + (ia * 2U));
|
|
ia = ia + twidCoefModifier;
|
|
// loop for butterfly
|
for (i = j; i < fftLen; i += n1)
|
{
|
l = i + n2;
|
|
T = _SIMD32_OFFSET(pSrc + (2 * i));
|
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S = _SIMD32_OFFSET(pSrc + (2 * l));
|
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R = __QSUB16(T, S);
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_SIMD32_OFFSET(pSrc + (2 * i)) = __SHADD16(T, S);
|
|
#ifndef ARM_MATH_BIG_ENDIAN
|
|
out1 = __SMUSD(coeff, R) >> 16;
|
out2 = __SMUADX(coeff, R);
|
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#else
|
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out1 = __SMUADX(R, coeff) >> 16U;
|
out2 = __SMUSD(__QSUB(0, coeff), R);
|
|
#endif // #ifndef ARM_MATH_BIG_ENDIAN
|
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_SIMD32_OFFSET(pSrc + (2U * l)) =
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(q31_t) ((out2) & 0xFFFF0000) | (out1 & 0x0000FFFF);
|
|
i += n1;
|
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l = i + n2;
|
|
T = _SIMD32_OFFSET(pSrc + (2 * i));
|
|
S = _SIMD32_OFFSET(pSrc + (2 * l));
|
|
R = __QSUB16(T, S);
|
|
_SIMD32_OFFSET(pSrc + (2 * i)) = __SHADD16(T, S);
|
|
#ifndef ARM_MATH_BIG_ENDIAN
|
|
out1 = __SMUSD(coeff, R) >> 16;
|
out2 = __SMUADX(coeff, R);
|
#else
|
|
out1 = __SMUADX(R, coeff) >> 16U;
|
out2 = __SMUSD(__QSUB(0, coeff), R);
|
|
#endif // #ifndef ARM_MATH_BIG_ENDIAN
|
|
_SIMD32_OFFSET(pSrc + (2U * l)) =
|
(q31_t) ((out2) & 0xFFFF0000) | (out1 & 0x0000FFFF);
|
|
} // butterfly loop end
|
|
} // groups loop end
|
|
twidCoefModifier = twidCoefModifier << 1U;
|
} // stages loop end
|
|
n1 = n2;
|
n2 = n2 >> 1;
|
ia = 0;
|
|
// loop for groups
|
for (j = 0; j < n2; j++)
|
{
|
coeff = _SIMD32_OFFSET(pCoef + (ia * 2U));
|
|
ia = ia + twidCoefModifier;
|
|
// loop for butterfly
|
for (i = j; i < fftLen; i += n1)
|
{
|
l = i + n2;
|
|
T = _SIMD32_OFFSET(pSrc + (2 * i));
|
|
S = _SIMD32_OFFSET(pSrc + (2 * l));
|
|
R = __QSUB16(T, S);
|
|
_SIMD32_OFFSET(pSrc + (2 * i)) = __QADD16(T, S);
|
|
_SIMD32_OFFSET(pSrc + (2U * l)) = R;
|
|
} // butterfly loop end
|
|
} // groups loop end
|
|
twidCoefModifier = twidCoefModifier << 1U;
|
|
#else
|
|
|
unsigned i, j, k, l;
|
unsigned n1, n2, ia;
|
q15_t xt, yt, cosVal, sinVal;
|
|
//N = fftLen;
|
n2 = fftLen;
|
|
n1 = n2;
|
n2 = n2 >> 1;
|
ia = 0;
|
|
// loop for groups
|
for (j = 0; j < n2; j++)
|
{
|
cosVal = pCoef[ia * 2];
|
sinVal = pCoef[(ia * 2) + 1];
|
ia = ia + twidCoefModifier;
|
|
// loop for butterfly
|
for (i = j; i < fftLen; i += n1)
|
{
|
l = i + n2;
|
xt = (pSrc[2 * i] >> 1U) - (pSrc[2 * l] >> 1U);
|
pSrc[2 * i] = ((pSrc[2 * i] >> 1U) + (pSrc[2 * l] >> 1U)) >> 1U;
|
|
yt = (pSrc[2 * i + 1] >> 1U) - (pSrc[2 * l + 1] >> 1U);
|
pSrc[2 * i + 1] =
|
((pSrc[2 * l + 1] >> 1U) + (pSrc[2 * i + 1] >> 1U)) >> 1U;
|
|
pSrc[2U * l] = (((int16_t) (((q31_t) xt * cosVal) >> 16)) -
|
((int16_t) (((q31_t) yt * sinVal) >> 16)));
|
|
pSrc[2U * l + 1U] = (((int16_t) (((q31_t) yt * cosVal) >> 16)) +
|
((int16_t) (((q31_t) xt * sinVal) >> 16)));
|
|
} // butterfly loop end
|
|
} // groups loop end
|
|
twidCoefModifier = twidCoefModifier << 1U;
|
|
// loop for stage
|
for (k = fftLen / 2; k > 2; k = k >> 1)
|
{
|
n1 = n2;
|
n2 = n2 >> 1;
|
ia = 0;
|
|
// loop for groups
|
for (j = 0; j < n2; j++)
|
{
|
cosVal = pCoef[ia * 2];
|
sinVal = pCoef[(ia * 2) + 1];
|
ia = ia + twidCoefModifier;
|
|
// loop for butterfly
|
for (i = j; i < fftLen; i += n1)
|
{
|
l = i + n2;
|
xt = pSrc[2 * i] - pSrc[2 * l];
|
pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]) >> 1U;
|
|
yt = pSrc[2 * i + 1] - pSrc[2 * l + 1];
|
pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]) >> 1U;
|
|
pSrc[2U * l] = (((int16_t) (((q31_t) xt * cosVal) >> 16)) -
|
((int16_t) (((q31_t) yt * sinVal) >> 16)));
|
|
pSrc[2U * l + 1U] = (((int16_t) (((q31_t) yt * cosVal) >> 16)) +
|
((int16_t) (((q31_t) xt * sinVal) >> 16)));
|
|
} // butterfly loop end
|
|
} // groups loop end
|
|
twidCoefModifier = twidCoefModifier << 1U;
|
} // stages loop end
|
|
n1 = n2;
|
n2 = n2 >> 1;
|
ia = 0;
|
|
cosVal = pCoef[ia * 2];
|
sinVal = pCoef[(ia * 2) + 1];
|
|
ia = ia + twidCoefModifier;
|
|
// loop for butterfly
|
for (i = 0; i < fftLen; i += n1)
|
{
|
l = i + n2;
|
xt = pSrc[2 * i] - pSrc[2 * l];
|
pSrc[2 * i] = (pSrc[2 * i] + pSrc[2 * l]);
|
|
yt = pSrc[2 * i + 1] - pSrc[2 * l + 1];
|
pSrc[2 * i + 1] = (pSrc[2 * l + 1] + pSrc[2 * i + 1]);
|
|
pSrc[2U * l] = xt;
|
|
pSrc[2U * l + 1U] = yt;
|
|
} // groups loop end
|
|
|
#endif // #if defined (ARM_MATH_DSP)
|
|
}
|
