/* ----------------------------------------------------------------------
* Project: CMSIS DSP Library
* Title: arm_cmplx_conj_q15.c
* Description: Q15 complex conjugate
*
* $Date: 18. March 2019
* $Revision: V1.6.0
*
* Target Processor: Cortex-M cores
* -------------------------------------------------------------------- */
/*
* Copyright (C) 2010-2019 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[in] pSrc points to the input vector
@param[out] pDst points to the output vector
@param[in] numSamples number of samples in each vector
@return none
@par Scaling and Overflow Behavior
The function uses saturating arithmetic.
The Q15 value -1 (0x8000) is saturated to the maximum allowable positive value 0x7FFF.
*/
void arm_cmplx_conj_q15(
const q15_t * pSrc,
q15_t * pDst,
uint32_t numSamples)
{
uint32_t blkCnt; /* Loop counter */
q31_t in1; /* Temporary input variable */
#if defined (ARM_MATH_LOOPUNROLL) && defined (ARM_MATH_DSP)
q31_t in2, in3, in4; /* Temporary input variables */
#endif
#if defined (ARM_MATH_LOOPUNROLL)
/* Loop unrolling: Compute 4 outputs at a time */
blkCnt = numSamples >> 2U;
while (blkCnt > 0U)
{
/* C[0] + jC[1] = A[0]+ j(-1)A[1] */
/* Calculate Complex Conjugate and store result in destination buffer. */
#if defined (ARM_MATH_DSP)
in1 = read_q15x2_ia ((q15_t **) &pSrc);
in2 = read_q15x2_ia ((q15_t **) &pSrc);
in3 = read_q15x2_ia ((q15_t **) &pSrc);
in4 = read_q15x2_ia ((q15_t **) &pSrc);
#ifndef ARM_MATH_BIG_ENDIAN
in1 = __QASX(0, in1);
in2 = __QASX(0, in2);
in3 = __QASX(0, in3);
in4 = __QASX(0, in4);
#else
in1 = __QSAX(0, in1);
in2 = __QSAX(0, in2);
in3 = __QSAX(0, in3);
in4 = __QSAX(0, 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);
write_q15x2_ia (&pDst, in1);
write_q15x2_ia (&pDst, in2);
write_q15x2_ia (&pDst, in3);
write_q15x2_ia (&pDst, in4);
#else
*pDst++ = *pSrc++;
in1 = *pSrc++;
*pDst++ = (in1 == (q15_t) 0x8000) ? (q15_t) 0x7fff : -in1;
*pDst++ = *pSrc++;
in1 = *pSrc++;
*pDst++ = (in1 == (q15_t) 0x8000) ? (q15_t) 0x7fff : -in1;
*pDst++ = *pSrc++;
in1 = *pSrc++;
*pDst++ = (in1 == (q15_t) 0x8000) ? (q15_t) 0x7fff : -in1;
*pDst++ = *pSrc++;
in1 = *pSrc++;
*pDst++ = (in1 == (q15_t) 0x8000) ? (q15_t) 0x7fff : -in1;
#endif /* #if defined (ARM_MATH_DSP) */
/* Decrement loop counter */
blkCnt--;
}
/* Loop unrolling: Compute remaining outputs */
blkCnt = numSamples % 0x4U;
#else
/* Initialize blkCnt with number of samples */
blkCnt = numSamples;
#endif /* #if defined (ARM_MATH_LOOPUNROLL) */
while (blkCnt > 0U)
{
/* C[0] + jC[1] = A[0]+ j(-1)A[1] */
/* Calculate Complex Conjugate and store result in destination buffer. */
*pDst++ = *pSrc++;
in1 = *pSrc++;
#if defined (ARM_MATH_DSP)
*pDst++ = __SSAT(-in1, 16);
#else
*pDst++ = (in1 == (q15_t) 0x8000) ? (q15_t) 0x7fff : -in1;
#endif
/* Decrement loop counter */
blkCnt--;
}
}
/**
@} end of cmplx_conj group
*/
