arm_cmplx_conj_q15.c
98 lines
| 2.7 KiB
| text/x-c
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CLexer
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r16 | /* ---------------------------------------------------------------------- | ||
* Copyright (C) 2010 ARM Limited. All rights reserved. | ||||
* | ||||
* $Date: 29. November 2010 | ||||
* $Revision: V1.0.3 | ||||
* | ||||
* Project: CMSIS DSP Library | ||||
* Title: arm_cmplx_conj_q15.c | ||||
* | ||||
* Description: Q15 complex conjugate. | ||||
* | ||||
* 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. | ||||
* ---------------------------------------------------------------------------- */ | ||||
#include "arm_math.h" | ||||
/** | ||||
* @ingroup groupCmplxMath | ||||
*/ | ||||
/** | ||||
* @addtogroup cmplx_conj | ||||
* @{ | ||||
*/ | ||||
/** | ||||
* @brief Q15 complex conjugate. | ||||
* @param *pSrc points to the input vector | ||||
* @param *pDst points to the output vector | ||||
* @param numSamples number of complex samples in each vector | ||||
* @return none. | ||||
* | ||||
* <b>Scaling and Overflow Behavior:</b> | ||||
* \par | ||||
* The function uses saturating arithmetic. | ||||
* The Q15 value -1 (0x8000) will be saturated to the maximum allowable positive value 0x7FFF. | ||||
*/ | ||||
void arm_cmplx_conj_q15( | ||||
q15_t * pSrc, | ||||
q15_t * pDst, | ||||
uint32_t numSamples) | ||||
{ | ||||
uint32_t blkCnt; /* loop counter */ | ||||
/*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[0]+jC[1] = A[0]+ j (-1) A[1] */ | ||||
/* Calculate Complex Conjugate and then store the results in the destination buffer. */ | ||||
*pDst++ = *pSrc++; | ||||
*pDst++ = __SSAT(-*pSrc++, 16); | ||||
*pDst++ = *pSrc++; | ||||
*pDst++ = __SSAT(-*pSrc++, 16); | ||||
*pDst++ = *pSrc++; | ||||
*pDst++ = __SSAT(-*pSrc++, 16); | ||||
*pDst++ = *pSrc++; | ||||
*pDst++ = __SSAT(-*pSrc++, 16); | ||||
/* Decrement the 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[0]+jC[1] = A[0]+ j (-1) A[1] */ | ||||
/* Calculate Complex Conjugate and then store the results in the destination buffer. */ | ||||
*pDst++ = *pSrc++; | ||||
*pDst++ = __SSAT(-*pSrc++, 16); | ||||
/* Decrement the loop counter */ | ||||
blkCnt--; | ||||
} | ||||
} | ||||
/** | ||||
* @} end of cmplx_conj group | ||||
*/ | ||||