/* ----------------------------------------------------------------------
* Project: CMSIS DSP Library
* Title: arm_cmplx_mult_real_q15.c
* Description: Q15 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 Q15 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 Q15 range [0x8000 0x7FFF] are saturated.
*/
void arm_cmplx_mult_real_q15(
const q15_t * pSrcCmplx,
const q15_t * pSrcReal,
q15_t * pCmplxDst,
uint32_t numSamples)
{
uint32_t blkCnt; /* Loop counter */
q15_t in; /* Temporary variable */
#if defined (ARM_MATH_LOOPUNROLL)
#if defined (ARM_MATH_DSP)
q31_t inA1, inA2; /* Temporary variables to hold input data */
q31_t inB1; /* Temporary variables to hold input data */
q15_t out1, out2, out3, out4; /* Temporary variables to hold output data */
q31_t mul1, mul2, mul3, mul4; /* Temporary variables to hold intermediate data */
#endif
/* 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]. */
#if defined (ARM_MATH_DSP)
/* read 2 complex numbers both real and imaginary from complex input buffer */
inA1 = read_q15x2_ia ((q15_t **) &pSrcCmplx);
inA2 = read_q15x2_ia ((q15_t **) &pSrcCmplx);
/* read 2 real values at a time from real input buffer */
inB1 = read_q15x2_ia ((q15_t **) &pSrcReal);
/* multiply complex number with real numbers */
#ifndef ARM_MATH_BIG_ENDIAN
mul1 = (q31_t) ((q15_t) (inA1) * (q15_t) (inB1));
mul2 = (q31_t) ((q15_t) (inA1 >> 16) * (q15_t) (inB1));
mul3 = (q31_t) ((q15_t) (inA2) * (q15_t) (inB1 >> 16));
mul4 = (q31_t) ((q15_t) (inA2 >> 16) * (q15_t) (inB1 >> 16));
#else
mul2 = (q31_t) ((q15_t) (inA1 >> 16) * (q15_t) (inB1 >> 16));
mul1 = (q31_t) ((q15_t) inA1 * (q15_t) (inB1 >> 16));
mul4 = (q31_t) ((q15_t) (inA2 >> 16) * (q15_t) inB1);
mul3 = (q31_t) ((q15_t) inA2 * (q15_t) inB1);
#endif /* #ifndef ARM_MATH_BIG_ENDIAN */
/* saturate the result */
out1 = (q15_t) __SSAT(mul1 >> 15U, 16);
out2 = (q15_t) __SSAT(mul2 >> 15U, 16);
out3 = (q15_t) __SSAT(mul3 >> 15U, 16);
out4 = (q15_t) __SSAT(mul4 >> 15U, 16);
/* pack real and imaginary outputs and store them to destination */
write_q15x2_ia (&pCmplxDst, __PKHBT(out1, out2, 16));
write_q15x2_ia (&pCmplxDst, __PKHBT(out3, out4, 16));
inA1 = read_q15x2_ia ((q15_t **) &pSrcCmplx);
inA2 = read_q15x2_ia ((q15_t **) &pSrcCmplx);
inB1 = read_q15x2_ia ((q15_t **) &pSrcReal);
#ifndef ARM_MATH_BIG_ENDIAN
mul1 = (q31_t) ((q15_t) (inA1) * (q15_t) (inB1));
mul2 = (q31_t) ((q15_t) (inA1 >> 16) * (q15_t) (inB1));
mul3 = (q31_t) ((q15_t) (inA2) * (q15_t) (inB1 >> 16));
mul4 = (q31_t) ((q15_t) (inA2 >> 16) * (q15_t) (inB1 >> 16));
#else
mul2 = (q31_t) ((q15_t) (inA1 >> 16) * (q15_t) (inB1 >> 16));
mul1 = (q31_t) ((q15_t) inA1 * (q15_t) (inB1 >> 16));
mul4 = (q31_t) ((q15_t) (inA2 >> 16) * (q15_t) inB1);
mul3 = (q31_t) ((q15_t) inA2 * (q15_t) inB1);
#endif /* #ifndef ARM_MATH_BIG_ENDIAN */
out1 = (q15_t) __SSAT(mul1 >> 15U, 16);
out2 = (q15_t) __SSAT(mul2 >> 15U, 16);
out3 = (q15_t) __SSAT(mul3 >> 15U, 16);
out4 = (q15_t) __SSAT(mul4 >> 15U, 16);
write_q15x2_ia (&pCmplxDst, __PKHBT(out1, out2, 16));
write_q15x2_ia (&pCmplxDst, __PKHBT(out3, out4, 16));
#else
in = *pSrcReal++;
*pCmplxDst++ = (q15_t) __SSAT((((q31_t) *pSrcCmplx++ * in) >> 15), 16);
*pCmplxDst++ = (q15_t) __SSAT((((q31_t) *pSrcCmplx++ * in) >> 15), 16);
in = *pSrcReal++;
*pCmplxDst++ = (q15_t) __SSAT((((q31_t) *pSrcCmplx++ * in) >> 15), 16);
*pCmplxDst++ = (q15_t) __SSAT((((q31_t) *pSrcCmplx++ * in) >> 15), 16);
in = *pSrcReal++;
*pCmplxDst++ = (q15_t) __SSAT((((q31_t) *pSrcCmplx++ * in) >> 15), 16);
*pCmplxDst++ = (q15_t) __SSAT((((q31_t) *pSrcCmplx++ * in) >> 15), 16);
in = *pSrcReal++;
*pCmplxDst++ = (q15_t) __SSAT((((q31_t) *pSrcCmplx++ * in) >> 15), 16);
*pCmplxDst++ = (q15_t) __SSAT((((q31_t) *pSrcCmplx++ * in) >> 15), 16);
#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++;
/* store the result in the destination buffer. */
*pCmplxDst++ = (q15_t) __SSAT((((q31_t) *pSrcCmplx++ * in) >> 15), 16);
*pCmplxDst++ = (q15_t) __SSAT((((q31_t) *pSrcCmplx++ * in) >> 15), 16);
/* Decrement loop counter */
blkCnt--;
}
}
/**
@} end of CmplxByRealMult group
*/
