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Sem-dma/Drivers/CMSIS/DSP/Source/ComplexMathFunctions/arm_cmplx_mag_q31.c
Julien Chevalley 902141e8b6 Initial commit
2023-12-11 14:43:05 +01:00

174 lines
4.7 KiB
C

/* ----------------------------------------------------------------------
* Project: CMSIS DSP Library
* Title: arm_cmplx_mag_q31.c
* Description: Q31 complex magnitude
*
* $Date: 27. January 2017
* $Revision: V.1.5.1
*
* Target Processor: Cortex-M cores
* -------------------------------------------------------------------- */
/*
* Copyright (C) 2010-2017 ARM Limited or its affiliates. All rights reserved.
*
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the License); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an AS IS BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "arm_math.h"
/**
* @ingroup groupCmplxMath
*/
/**
* @addtogroup cmplx_mag
* @{
*/
/**
* @brief Q31 complex magnitude
* @param *pSrc points to the complex input vector
* @param *pDst points to the real output vector
* @param numSamples number of complex samples in the input vector
* @return none.
*
* <b>Scaling and Overflow Behavior:</b>
* \par
* The function implements 1.31 by 1.31 multiplications and finally output is converted into 2.30 format.
* Input down scaling is not required.
*/
void arm_cmplx_mag_q31(
q31_t * pSrc,
q31_t * pDst,
uint32_t numSamples)
{
q31_t real, imag; /* Temporary variables to hold input values */
q31_t acc0, acc1; /* Accumulators */
uint32_t blkCnt; /* loop counter */
#if defined (ARM_MATH_DSP)
/* Run the below code for Cortex-M4 and Cortex-M3 */
q31_t real1, real2, imag1, imag2; /* Temporary variables to hold input values */
q31_t out1, out2, out3, out4; /* Accumulators */
q63_t mul1, mul2, mul3, mul4; /* Temporary variables */
/*loop Unrolling */
blkCnt = numSamples >> 2U;
/* First part of the processing with loop unrolling. Compute 4 outputs at a time.
** a second loop below computes the remaining 1 to 3 samples. */
while (blkCnt > 0U)
{
/* read complex input from source buffer */
real1 = pSrc[0];
imag1 = pSrc[1];
real2 = pSrc[2];
imag2 = pSrc[3];
/* calculate power of input values */
mul1 = (q63_t) real1 *real1;
mul2 = (q63_t) imag1 *imag1;
mul3 = (q63_t) real2 *real2;
mul4 = (q63_t) imag2 *imag2;
/* get the result to 3.29 format */
out1 = (q31_t) (mul1 >> 33);
out2 = (q31_t) (mul2 >> 33);
out3 = (q31_t) (mul3 >> 33);
out4 = (q31_t) (mul4 >> 33);
/* add real and imaginary accumulators */
out1 = out1 + out2;
out3 = out3 + out4;
/* read complex input from source buffer */
real1 = pSrc[4];
imag1 = pSrc[5];
real2 = pSrc[6];
imag2 = pSrc[7];
/* calculate square root */
arm_sqrt_q31(out1, &pDst[0]);
/* calculate power of input values */
mul1 = (q63_t) real1 *real1;
/* calculate square root */
arm_sqrt_q31(out3, &pDst[1]);
/* calculate power of input values */
mul2 = (q63_t) imag1 *imag1;
mul3 = (q63_t) real2 *real2;
mul4 = (q63_t) imag2 *imag2;
/* get the result to 3.29 format */
out1 = (q31_t) (mul1 >> 33);
out2 = (q31_t) (mul2 >> 33);
out3 = (q31_t) (mul3 >> 33);
out4 = (q31_t) (mul4 >> 33);
/* add real and imaginary accumulators */
out1 = out1 + out2;
out3 = out3 + out4;
/* calculate square root */
arm_sqrt_q31(out1, &pDst[2]);
/* increment destination by 8 to process next samples */
pSrc += 8U;
/* calculate square root */
arm_sqrt_q31(out3, &pDst[3]);
/* increment destination by 4 to process next samples */
pDst += 4U;
/* Decrement the loop counter */
blkCnt--;
}
/* If the numSamples is not a multiple of 4, compute any remaining output samples here.
** No loop unrolling is used. */
blkCnt = numSamples % 0x4U;
#else
/* Run the below code for Cortex-M0 */
blkCnt = numSamples;
#endif /* #if defined (ARM_MATH_DSP) */
while (blkCnt > 0U)
{
/* C[0] = sqrt(A[0] * A[0] + A[1] * A[1]) */
real = *pSrc++;
imag = *pSrc++;
acc0 = (q31_t) (((q63_t) real * real) >> 33);
acc1 = (q31_t) (((q63_t) imag * imag) >> 33);
/* store the result in 2.30 format in the destination buffer. */
arm_sqrt_q31(acc0 + acc1, pDst++);
/* Decrement the loop counter */
blkCnt--;
}
}
/**
* @} end of cmplx_mag group
*/