arm_cmplx_dot_prod_q31.c
118 lines
| 4.0 KiB
| text/x-c
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CLexer
jeandet@pc-de-jeandet3.lab-lpp.local
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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_dot_prod_q31.c | ||||
| * | ||||
| * Description: Q31 complex dot product | ||||
| * | ||||
| * 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_dot_prod | ||||
| * @{ | ||||
| */ | ||||
| /** | ||||
| * @brief Q31 complex dot product | ||||
| * @param *pSrcA points to the first input vector | ||||
| * @param *pSrcB points to the second input vector | ||||
| * @param numSamples number of complex samples in each vector | ||||
| * @param *realResult real part of the result returned here | ||||
| * @param *imagResult imaginary part of the result returned here | ||||
| * @return none. | ||||
| * | ||||
| * <b>Scaling and Overflow Behavior:</b> | ||||
| * \par | ||||
| * The function is implemented using an internal 64-bit accumulator. | ||||
| * The intermediate 1.31 by 1.31 multiplications are performed with 64-bit precision and then shifted to 16.48 format. | ||||
| * The internal real and imaginary accumulators are in 16.48 format and provide 15 guard bits. | ||||
| * Additions are nonsaturating and no overflow will occur as long as <code>numSamples</code> is less than 32768. | ||||
| * The return results <code>realResult</code> and <code>imagResult</code> are in 16.48 format. | ||||
| * Input down scaling is not required. | ||||
| */ | ||||
| void arm_cmplx_dot_prod_q31( | ||||
| q31_t * pSrcA, | ||||
| q31_t * pSrcB, | ||||
| uint32_t numSamples, | ||||
| q63_t * realResult, | ||||
| q63_t * imagResult) | ||||
| { | ||||
| q63_t real_sum = 0, imag_sum = 0; /* Temporary result storage */ | ||||
| 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) | ||||
| { | ||||
| /* CReal = A[0]* B[0] + A[2]* B[2] + A[4]* B[4] + .....+ A[numSamples-2]* B[numSamples-2] */ | ||||
| /* Convert real data in 2.62 to 16.48 by 14 right shifts */ | ||||
| real_sum += (q63_t) * pSrcA++ * (*pSrcB++) >> 14; | ||||
| /* CImag = A[1]* B[1] + A[3]* B[3] + A[5]* B[5] + .....+ A[numSamples-1]* B[numSamples-1] */ | ||||
| /* Convert imag data in 2.62 to 16.48 by 14 right shifts */ | ||||
| imag_sum += (q63_t) * pSrcA++ * (*pSrcB++) >> 14; | ||||
| real_sum += (q63_t) * pSrcA++ * (*pSrcB++) >> 14; | ||||
| imag_sum += (q63_t) * pSrcA++ * (*pSrcB++) >> 14; | ||||
| real_sum += (q63_t) * pSrcA++ * (*pSrcB++) >> 14; | ||||
| imag_sum += (q63_t) * pSrcA++ * (*pSrcB++) >> 14; | ||||
| real_sum += (q63_t) * pSrcA++ * (*pSrcB++) >> 14; | ||||
| imag_sum += (q63_t) * pSrcA++ * (*pSrcB++) >> 14; | ||||
| /* 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) | ||||
| { | ||||
| /* CReal = A[0]* B[0] + A[2]* B[2] + A[4]* B[4] + .....+ A[numSamples-2]* B[numSamples-2] */ | ||||
| real_sum += (q63_t) * pSrcA++ * (*pSrcB++) >> 14; | ||||
| /* CImag = A[1]* B[1] + A[3]* B[3] + A[5]* B[5] + .....+ A[numSamples-1]* B[numSamples-1] */ | ||||
| imag_sum += (q63_t) * pSrcA++ * (*pSrcB++) >> 14; | ||||
| /* Decrement the loop counter */ | ||||
| blkCnt--; | ||||
| } | ||||
| /* Store the real and imaginary results in 16.48 format */ | ||||
| *realResult = real_sum; | ||||
| *imagResult = imag_sum; | ||||
| } | ||||
| /** | ||||
| * @} end of cmplx_dot_prod group | ||||
| */ | ||||