/* ----------------------------------------------------------------------
* Copyright (C) 2010 ARM Limited. All rights reserved.
*
* $Date: 15. February 2012
* $Revision: V1.1.0
*
* Project: CMSIS DSP Library
* Title: arm_cmplx_mult_real_q15.c
*
* Description: Q15 complex by real multiplication
*
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
*
* Version 1.1.0 2012/02/15
* Updated with more optimizations, bug fixes and minor API changes.
*
* Version 1.0.10 2011/7/15
* Big Endian support added and Merged M0 and M3/M4 Source code.
*
* Version 1.0.3 2010/11/29
* Re-organized the CMSIS folders and updated documentation.
*
* Version 1.0.2 2010/11/11
* Documentation updated.
*
* Version 1.0.1 2010/10/05
* Production release and review comments incorporated.
*
* Version 1.0.0 2010/09/20
* Production release and review comments incorporated.
* -------------------------------------------------------------------- */
#include "arm_math.h"
/**
* @ingroup groupCmplxMath
*/
/**
* @addtogroup CmplxByRealMult
* @{
*/
/**
* @brief Q15 complex-by-real multiplication
* @param[in] *pSrcCmplx points to the complex input vector
* @param[in] *pSrcReal points to the real input vector
* @param[out] *pCmplxDst points to the complex output vector
* @param[in] numSamples number of samples in each vector
* @return none.
*
* <b>Scaling and Overflow Behavior:</b>
* \par
* The function uses saturating arithmetic.
* Results outside of the allowable Q15 range [0x8000 0x7FFF] will be saturated.
*/
void arm_cmplx_mult_real_q15(
q15_t * pSrcCmplx,
q15_t * pSrcReal,
q15_t * pCmplxDst,
uint32_t numSamples)
{
q15_t in; /* Temporary variable to store input value */
#ifndef ARM_MATH_CM0
/* Run the below code for Cortex-M4 and Cortex-M3 */
uint32_t blkCnt; /* loop counters */
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 */
/* 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[2 * i] = A[2 * i] * B[i]. */
/* C[2 * i + 1] = A[2 * i + 1] * B[i]. */
/* read complex number both real and imaginary from complex input buffer */
inA1 = *__SIMD32(pSrcCmplx)++;
/* read two real values at a time from real input buffer */
inB1 = *__SIMD32(pSrcReal)++;
/* read complex number both real and imaginary from complex input buffer */
inA2 = *__SIMD32(pSrcCmplx)++;
/* 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 */
*__SIMD32(pCmplxDst)++ = __PKHBT(out1, out2, 16);
*__SIMD32(pCmplxDst)++ = __PKHBT(out3, out4, 16);
inA1 = *__SIMD32(pSrcCmplx)++;
inB1 = *__SIMD32(pSrcReal)++;
inA2 = *__SIMD32(pSrcCmplx)++;
#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);
*__SIMD32(pCmplxDst)++ = __PKHBT(out1, out2, 16);
*__SIMD32(pCmplxDst)++ = __PKHBT(out3, out4, 16);
/* Decrement the numSamples 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[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 the numSamples loop counter */
blkCnt--;
}
#else
/* Run the below code for Cortex-M0 */
while(numSamples > 0u)
{
/* realOut = realA * realB. */
/* imagOut = imagA * realB. */
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 the numSamples loop counter */
numSamples--;
}
#endif /* #ifndef ARM_MATH_CM0 */
}
/**
* @} end of CmplxByRealMult group
*/