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/* ----------------------------------------------------------------------
* Project: CMSIS DSP Library
* Title: arm_cmplx_mult_real_q31.c
* Description: Q31 complex by real multiplication
*
* $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 CmplxByRealMult
@{
*/
/**
@brief Q31 complex-by-real multiplication.
@param[in] pSrcCmplx points to complex input vector
@param[in] pSrcReal points to real input vector
@param[out] pCmplxDst points to complex output vector
@param[in] numSamples number of samples in each vector
@return none
@par Scaling and Overflow Behavior
The function uses saturating arithmetic.
Results outside of the allowable Q31 range[0x80000000 0x7FFFFFFF] are saturated.
*/
void arm_cmplx_mult_real_q31(
const q31_t * pSrcCmplx,
const q31_t * pSrcReal,
q31_t * pCmplxDst,
uint32_t numSamples)
{
uint32_t blkCnt; /* Loop counter */
q31_t in; /* Temporary variable */
#if defined (ARM_MATH_LOOPUNROLL)
/* Loop unrolling: Compute 4 outputs at a time */
blkCnt = numSamples >> 2U;
while (blkCnt > 0U)
{
/* C[2 * i ] = A[2 * i ] * B[i]. */
/* C[2 * i + 1] = A[2 * i + 1] * B[i]. */
in = *pSrcReal++;
#if defined (ARM_MATH_DSP)
/* store saturated result in 1.31 format to destination buffer */
*pCmplxDst++ = (__SSAT((q31_t) (((q63_t) *pSrcCmplx++ * in) >> 32), 31) << 1);
*pCmplxDst++ = (__SSAT((q31_t) (((q63_t) *pSrcCmplx++ * in) >> 32), 31) << 1);
#else
/* store result in destination buffer. */
*pCmplxDst++ = (q31_t) clip_q63_to_q31(((q63_t) *pSrcCmplx++ * in) >> 31);
*pCmplxDst++ = (q31_t) clip_q63_to_q31(((q63_t) *pSrcCmplx++ * in) >> 31);
#endif
in = *pSrcReal++;
#if defined (ARM_MATH_DSP)
*pCmplxDst++ = (__SSAT((q31_t) (((q63_t) *pSrcCmplx++ * in) >> 32), 31) << 1);
*pCmplxDst++ = (__SSAT((q31_t) (((q63_t) *pSrcCmplx++ * in) >> 32), 31) << 1);
#else
*pCmplxDst++ = (q31_t) clip_q63_to_q31(((q63_t) *pSrcCmplx++ * in) >> 31);
*pCmplxDst++ = (q31_t) clip_q63_to_q31(((q63_t) *pSrcCmplx++ * in) >> 31);
#endif
in = *pSrcReal++;
#if defined (ARM_MATH_DSP)
*pCmplxDst++ = (__SSAT((q31_t) (((q63_t) *pSrcCmplx++ * in) >> 32), 31) << 1);
*pCmplxDst++ = (__SSAT((q31_t) (((q63_t) *pSrcCmplx++ * in) >> 32), 31) << 1);
#else
*pCmplxDst++ = (q31_t) clip_q63_to_q31(((q63_t) *pSrcCmplx++ * in) >> 31);
*pCmplxDst++ = (q31_t) clip_q63_to_q31(((q63_t) *pSrcCmplx++ * in) >> 31);
#endif
in = *pSrcReal++;
#if defined (ARM_MATH_DSP)
*pCmplxDst++ = (__SSAT((q31_t) (((q63_t) *pSrcCmplx++ * in) >> 32), 31) << 1);
*pCmplxDst++ = (__SSAT((q31_t) (((q63_t) *pSrcCmplx++ * in) >> 32), 31) << 1);
#else
*pCmplxDst++ = (q31_t) clip_q63_to_q31(((q63_t) *pSrcCmplx++ * in) >> 31);
*pCmplxDst++ = (q31_t) clip_q63_to_q31(((q63_t) *pSrcCmplx++ * in) >> 31);
#endif
/* 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[2 * i ] = A[2 * i ] * B[i]. */
/* C[2 * i + 1] = A[2 * i + 1] * B[i]. */
in = *pSrcReal++;
#if defined (ARM_MATH_DSP)
/* store saturated result in 1.31 format to destination buffer */
*pCmplxDst++ = (__SSAT((q31_t) (((q63_t) *pSrcCmplx++ * in) >> 32), 31) << 1);
*pCmplxDst++ = (__SSAT((q31_t) (((q63_t) *pSrcCmplx++ * in) >> 32), 31) << 1);
#else
/* store result in destination buffer. */
*pCmplxDst++ = (q31_t) clip_q63_to_q31(((q63_t) *pSrcCmplx++ * in) >> 31);
*pCmplxDst++ = (q31_t) clip_q63_to_q31(((q63_t) *pSrcCmplx++ * in) >> 31);
#endif
/* Decrement loop counter */
blkCnt--;
}
}
/**
@} end of CmplxByRealMult group
*/
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