/* ----------------------------------------------------------------------
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* Project: CMSIS DSP Library
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* Title: arm_cmplx_mag_squared_q31.c
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* Description: Q31 complex magnitude squared
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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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/**
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* @ingroup groupCmplxMath
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*/
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/**
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* @addtogroup cmplx_mag_squared
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* @{
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*/
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/**
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* @brief Q31 complex magnitude squared
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* @param *pSrc points to the complex input vector
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* @param *pDst points to the real output vector
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* @param numSamples number of complex samples in the input vector
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* @return none.
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*
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* <b>Scaling and Overflow Behavior:</b>
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* \par
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* The function implements 1.31 by 1.31 multiplications and finally output is converted into 3.29 format.
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* Input down scaling is not required.
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*/
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void arm_cmplx_mag_squared_q31(
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q31_t * pSrc,
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q31_t * pDst,
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uint32_t numSamples)
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{
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q31_t real, imag; /* Temporary variables to store real and imaginary values */
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q31_t acc0, acc1; /* Accumulators */
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#if defined (ARM_MATH_DSP)
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/* Run the below code for Cortex-M4 and Cortex-M3 */
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uint32_t blkCnt; /* loop counter */
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/* loop Unrolling */
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blkCnt = numSamples >> 2U;
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/* First part of the processing with loop unrolling. Compute 4 outputs at a time.
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** a second loop below computes the remaining 1 to 3 samples. */
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while (blkCnt > 0U)
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{
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/* C[0] = (A[0] * A[0] + A[1] * A[1]) */
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real = *pSrc++;
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imag = *pSrc++;
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acc0 = (q31_t) (((q63_t) real * real) >> 33);
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acc1 = (q31_t) (((q63_t) imag * imag) >> 33);
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/* store the result in 3.29 format in the destination buffer. */
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*pDst++ = acc0 + acc1;
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real = *pSrc++;
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imag = *pSrc++;
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acc0 = (q31_t) (((q63_t) real * real) >> 33);
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acc1 = (q31_t) (((q63_t) imag * imag) >> 33);
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/* store the result in 3.29 format in the destination buffer. */
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*pDst++ = acc0 + acc1;
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real = *pSrc++;
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imag = *pSrc++;
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acc0 = (q31_t) (((q63_t) real * real) >> 33);
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acc1 = (q31_t) (((q63_t) imag * imag) >> 33);
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/* store the result in 3.29 format in the destination buffer. */
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*pDst++ = acc0 + acc1;
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real = *pSrc++;
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imag = *pSrc++;
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acc0 = (q31_t) (((q63_t) real * real) >> 33);
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acc1 = (q31_t) (((q63_t) imag * imag) >> 33);
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/* store the result in 3.29 format in the destination buffer. */
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*pDst++ = acc0 + acc1;
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/* Decrement the loop counter */
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blkCnt--;
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}
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/* If the numSamples is not a multiple of 4, compute any remaining output samples here.
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** No loop unrolling is used. */
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blkCnt = numSamples % 0x4U;
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while (blkCnt > 0U)
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{
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/* C[0] = (A[0] * A[0] + A[1] * A[1]) */
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real = *pSrc++;
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imag = *pSrc++;
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acc0 = (q31_t) (((q63_t) real * real) >> 33);
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acc1 = (q31_t) (((q63_t) imag * imag) >> 33);
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/* store the result in 3.29 format in the destination buffer. */
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*pDst++ = acc0 + acc1;
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/* Decrement the loop counter */
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blkCnt--;
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}
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#else
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/* Run the below code for Cortex-M0 */
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while (numSamples > 0U)
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{
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/* out = ((real * real) + (imag * imag)) */
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real = *pSrc++;
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imag = *pSrc++;
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acc0 = (q31_t) (((q63_t) real * real) >> 33);
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acc1 = (q31_t) (((q63_t) imag * imag) >> 33);
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/* store the result in 3.29 format in the destination buffer. */
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*pDst++ = acc0 + acc1;
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/* Decrement the loop counter */
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numSamples--;
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}
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#endif /* #if defined (ARM_MATH_DSP) */
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}
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/**
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* @} end of cmplx_mag_squared group
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*/
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