|
|
/* ----------------------------------------------------------------------
|
|
|
* Copyright (C) 2010 ARM Limited. All rights reserved.
|
|
|
*
|
|
|
* $Date: 29. November 2010
|
|
|
* $Revision: V1.0.3
|
|
|
*
|
|
|
* Project: CMSIS DSP Library
|
|
|
* Title: arm_mult_q15.c
|
|
|
*
|
|
|
* Description: Q15 vector multiplication.
|
|
|
*
|
|
|
* Target Processor: Cortex-M4/Cortex-M3
|
|
|
*
|
|
|
* 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.
|
|
|
*
|
|
|
* Version 0.0.5 2010/04/26
|
|
|
* incorporated review comments and updated with latest CMSIS layer
|
|
|
*
|
|
|
* Version 0.0.3 2010/03/10
|
|
|
* Initial version
|
|
|
* -------------------------------------------------------------------- */
|
|
|
|
|
|
#include "arm_math.h"
|
|
|
|
|
|
/**
|
|
|
* @ingroup groupMath
|
|
|
*/
|
|
|
|
|
|
/**
|
|
|
* @addtogroup BasicMult
|
|
|
* @{
|
|
|
*/
|
|
|
|
|
|
|
|
|
/**
|
|
|
* @brief Q15 vector multiplication
|
|
|
* @param[in] *pSrcA points to the first input vector
|
|
|
* @param[in] *pSrcB points to the second input vector
|
|
|
* @param[out] *pDst points to the output vector
|
|
|
* @param[in] blockSize 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_mult_q15(
|
|
|
q15_t * pSrcA,
|
|
|
q15_t * pSrcB,
|
|
|
q15_t * pDst,
|
|
|
uint32_t blockSize)
|
|
|
{
|
|
|
uint32_t blkCnt; /* loop counters */
|
|
|
|
|
|
/* loop Unrolling */
|
|
|
blkCnt = blockSize >> 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 = A * B */
|
|
|
/* Multiply the inputs and store the result in the destination buffer */
|
|
|
*pDst++ = (q15_t) __SSAT((((q31_t) (*pSrcA++) * (*pSrcB++)) >> 15), 16);
|
|
|
*pDst++ = (q15_t) __SSAT((((q31_t) (*pSrcA++) * (*pSrcB++)) >> 15), 16);
|
|
|
*pDst++ = (q15_t) __SSAT((((q31_t) (*pSrcA++) * (*pSrcB++)) >> 15), 16);
|
|
|
*pDst++ = (q15_t) __SSAT((((q31_t) (*pSrcA++) * (*pSrcB++)) >> 15), 16);
|
|
|
|
|
|
/* Decrement the blockSize loop counter */
|
|
|
blkCnt--;
|
|
|
}
|
|
|
|
|
|
/* If the blockSize is not a multiple of 4, compute any remaining output samples here.
|
|
|
** No loop unrolling is used. */
|
|
|
blkCnt = blockSize % 0x4u;
|
|
|
|
|
|
while(blkCnt > 0u)
|
|
|
{
|
|
|
/* C = A * B */
|
|
|
/* Multiply the inputs and store the result in the destination buffer */
|
|
|
*pDst++ = (q15_t) __SSAT((((q31_t) (*pSrcA++) * (*pSrcB++)) >> 15), 16);
|
|
|
|
|
|
/* Decrement the blockSize loop counter */
|
|
|
blkCnt--;
|
|
|
}
|
|
|
}
|
|
|
|
|
|
/**
|
|
|
* @} end of BasicMult group
|
|
|
*/
|
|
|
|
