CMSIS DSP Software Library: arm_cmplx_dot_prod_q31.c Source File

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# arm_cmplx_dot_prod_q31.c

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    00001 /* ----------------------------------------------------------------------
    00002 * Copyright (C) 2010 ARM Limited. All rights reserved.
    00003 *
    00004 * $Date:        15. July 2011
    00005 * $Revision:    V1.0.10
    00006 *
    00007 * Project:      CMSIS DSP Library
    00008 * Title:        arm_cmplx_dot_prod_q31.c
    00009 *
    00010 * Description:  Q31 complex dot product
    00011 *
    00012 * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
    00013 *
    00014 * Version 1.0.10 2011/7/15
    00015 *    Big Endian support added and Merged M0 and M3/M4 Source code.
    00016 *
    00017 * Version 1.0.3 2010/11/29
    00018 *    Re-organized the CMSIS folders and updated documentation.
    00019 *
    00020 * Version 1.0.2 2010/11/11
    00021 *    Documentation updated.
    00022 *
    00023 * Version 1.0.1 2010/10/05
    00024 *    Production release and review comments incorporated.
    00025 *
    00026 * Version 1.0.0 2010/09/20
    00027 *    Production release and review comments incorporated.
    00028 * -------------------------------------------------------------------- */
    00029
    00030 #include "arm_math.h"
    00031
    00060 void arm_cmplx_dot_prod_q31(
    00061   q31_t * pSrcA,
    00062   q31_t * pSrcB,
    00063   uint32_t numSamples,
    00064   q63_t * realResult,
    00065   q63_t * imagResult)
    00066 {
    00067   q63_t real_sum = 0, imag_sum = 0;              /* Temporary result storage */
    00068
    00069 #ifndef ARM_MATH_CM0
    00070
    00071   /* Run the below code for Cortex-M4 and Cortex-M3 */
    00072   uint32_t blkCnt;                               /* loop counter */
    00073
    00074
    00075   /*loop Unrolling */
    00076   blkCnt = numSamples >> 2u;
    00077
    00078   /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.
    00079    ** a second loop below computes the remaining 1 to 3 samples. */
    00080   while(blkCnt > 0u)
    00081   {
    00082     /* CReal = A[0]* B[0] + A[2]* B[2] + A[4]* B[4] + .....+ A[numSamples-2]* B[numSamples-2] */
    00083     /* Convert real data in 2.62 to 16.48 by 14 right shifts */
    00084     real_sum += (q63_t) * pSrcA++ * (*pSrcB++) >> 14;
    00085     /* CImag = A[1]* B[1] + A[3]* B[3] + A[5]* B[5] + .....+ A[numSamples-1]* B[numSamples-1] */
    00086     /* Convert imag data in 2.62 to 16.48 by 14 right shifts */
    00087     imag_sum += (q63_t) * pSrcA++ * (*pSrcB++) >> 14;
    00088
    00089     real_sum += (q63_t) * pSrcA++ * (*pSrcB++) >> 14;
    00090     imag_sum += (q63_t) * pSrcA++ * (*pSrcB++) >> 14;
    00091
    00092     real_sum += (q63_t) * pSrcA++ * (*pSrcB++) >> 14;
    00093     imag_sum += (q63_t) * pSrcA++ * (*pSrcB++) >> 14;
    00094
    00095     real_sum += (q63_t) * pSrcA++ * (*pSrcB++) >> 14;
    00096     imag_sum += (q63_t) * pSrcA++ * (*pSrcB++) >> 14;
    00097
    00098
    00099     /* Decrement the loop counter */
    00100     blkCnt--;
    00101   }
    00102
    00103   /* If the numSamples  is not a multiple of 4, compute any remaining output samples here.
    00104    ** No loop unrolling is used. */
    00105   blkCnt = numSamples % 0x4u;
    00106
    00107   while(blkCnt > 0u)
    00108   {
    00109     /* CReal = A[0]* B[0] + A[2]* B[2] + A[4]* B[4] + .....+ A[numSamples-2]* B[numSamples-2] */
    00110     real_sum += (q63_t) * pSrcA++ * (*pSrcB++) >> 14;
    00111     /* CImag = A[1]* B[1] + A[3]* B[3] + A[5]* B[5] + .....+ A[numSamples-1]* B[numSamples-1] */
    00112     imag_sum += (q63_t) * pSrcA++ * (*pSrcB++) >> 14;
    00113
    00114     /* Decrement the loop counter */
    00115     blkCnt--;
    00116   }
    00117
    00118 #else
    00119
    00120   /* Run the below code for Cortex-M0 */
    00121
    00122   while(numSamples > 0u)
    00123   {
    00124     /* outReal = realA[0]* realB[0] + realA[2]* realB[2] + realA[4]* realB[4] + .....+ realA[numSamples-2]* realB[numSamples-2] */
    00125     real_sum += (q63_t) * pSrcA++ * (*pSrcB++) >> 14;
    00126     /* outImag = imagA[1]* imagB[1] + imagA[3]* imagB[3] + imagA[5]* imagB[5] + .....+ imagA[numSamples-1]* imagB[numSamples-1] */
    00127     imag_sum += (q63_t) * pSrcA++ * (*pSrcB++) >> 14;
    00128
    00129     /* Decrement the loop counter */
    00130     numSamples--;
    00131   }
    00132
    00133 #endif /* #ifndef ARM_MATH_CM0 */
    00134
    00135   /* Store the real and imaginary results in 16.48 format  */
    00136   *realResult = real_sum;
    00137   *imagResult = imag_sum;
    00138 }
    00139

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