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Sem-dma/Drivers/CMSIS/DSP/Source/ComplexMathFunctions/arm_cmplx_conj_q15.c
Julien Chevalley 902141e8b6 Initial commit
2023-12-11 14:43:05 +01:00

150 lines
3.8 KiB
C

/* ----------------------------------------------------------------------
* Project: CMSIS DSP Library
* Title: arm_cmplx_conj_q15.c
* Description: Q15 complex conjugate
*
* $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_conj
* @{
*/
/**
* @brief Q15 complex conjugate.
* @param *pSrc points to the input vector
* @param *pDst points to the output vector
* @param numSamples number of complex samples in each vector
* @return none.
*
* <b>Scaling and Overflow Behavior:</b>
* \par
* The function uses saturating arithmetic.
* The Q15 value -1 (0x8000) will be saturated to the maximum allowable positive value 0x7FFF.
*/
void arm_cmplx_conj_q15(
q15_t * pSrc,
q15_t * pDst,
uint32_t numSamples)
{
#if defined (ARM_MATH_DSP)
/* Run the below code for Cortex-M4 and Cortex-M3 */
uint32_t blkCnt; /* loop counter */
q31_t in1, in2, in3, in4;
q31_t zero = 0;
/*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)
{
/* C[0]+jC[1] = A[0]+ j (-1) A[1] */
/* Calculate Complex Conjugate and then store the results in the destination buffer. */
in1 = *__SIMD32(pSrc)++;
in2 = *__SIMD32(pSrc)++;
in3 = *__SIMD32(pSrc)++;
in4 = *__SIMD32(pSrc)++;
#ifndef ARM_MATH_BIG_ENDIAN
in1 = __QASX(zero, in1);
in2 = __QASX(zero, in2);
in3 = __QASX(zero, in3);
in4 = __QASX(zero, in4);
#else
in1 = __QSAX(zero, in1);
in2 = __QSAX(zero, in2);
in3 = __QSAX(zero, in3);
in4 = __QSAX(zero, in4);
#endif /* #ifndef ARM_MATH_BIG_ENDIAN */
in1 = ((uint32_t) in1 >> 16) | ((uint32_t) in1 << 16);
in2 = ((uint32_t) in2 >> 16) | ((uint32_t) in2 << 16);
in3 = ((uint32_t) in3 >> 16) | ((uint32_t) in3 << 16);
in4 = ((uint32_t) in4 >> 16) | ((uint32_t) in4 << 16);
*__SIMD32(pDst)++ = in1;
*__SIMD32(pDst)++ = in2;
*__SIMD32(pDst)++ = in3;
*__SIMD32(pDst)++ = in4;
/* 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;
while (blkCnt > 0U)
{
/* C[0]+jC[1] = A[0]+ j (-1) A[1] */
/* Calculate Complex Conjugate and then store the results in the destination buffer. */
*pDst++ = *pSrc++;
*pDst++ = __SSAT(-*pSrc++, 16);
/* Decrement the loop counter */
blkCnt--;
}
#else
q15_t in;
/* Run the below code for Cortex-M0 */
while (numSamples > 0U)
{
/* realOut + j (imagOut) = realIn+ j (-1) imagIn */
/* Calculate Complex Conjugate and then store the results in the destination buffer. */
*pDst++ = *pSrc++;
in = *pSrc++;
*pDst++ = (in == (q15_t) 0x8000) ? 0x7fff : -in;
/* Decrement the loop counter */
numSamples--;
}
#endif /* #if defined (ARM_MATH_DSP) */
}
/**
* @} end of cmplx_conj group
*/