| /* ---------------------------------------------------------------------- |
| * Copyright (C) 2010 ARM Limited. All rights reserved. |
| * |
| * $Date: 15. July 2011 |
| * $Revision: V1.0.10 |
| * |
| * Project: CMSIS DSP Library |
| * Title: arm_cmplx_dot_prod_q31.c |
| * |
| * Description: Q31 complex dot product |
| * |
| * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0 |
| * |
| * 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 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 */ |
| |
| #ifndef ARM_MATH_CM0 |
| |
| /* Run the below code for Cortex-M4 and Cortex-M3 */ |
| 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--; |
| } |
| |
| #else |
| |
| /* Run the below code for Cortex-M0 */ |
| |
| while(numSamples > 0u) |
| { |
| /* outReal = realA[0]* realB[0] + realA[2]* realB[2] + realA[4]* realB[4] + .....+ realA[numSamples-2]* realB[numSamples-2] */ |
| real_sum += (q63_t) * pSrcA++ * (*pSrcB++) >> 14; |
| /* outImag = imagA[1]* imagB[1] + imagA[3]* imagB[3] + imagA[5]* imagB[5] + .....+ imagA[numSamples-1]* imagB[numSamples-1] */ |
| imag_sum += (q63_t) * pSrcA++ * (*pSrcB++) >> 14; |
| |
| /* Decrement the loop counter */ |
| numSamples--; |
| } |
| |
| #endif /* #ifndef ARM_MATH_CM0 */ |
| |
| /* Store the real and imaginary results in 16.48 format */ |
| *realResult = real_sum; |
| *imagResult = imag_sum; |
| } |
| |
| /** |
| * @} end of cmplx_dot_prod group |
| */ |