CMSIS DSP Software Library: arm_dot_prod_q31.c Source File

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# arm_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_dot_prod_q31.c
    00009 *
    00010 * Description:  Q31 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 * Version 0.0.7  2010/06/10
    00030 *    Misra-C changes done
    00031 * -------------------------------------------------------------------- */
    00032
    00033 #include "arm_math.h"
    00034
    00062 void arm_dot_prod_q31(
    00063   q31_t * pSrcA,
    00064   q31_t * pSrcB,
    00065   uint32_t blockSize,
    00066   q63_t * result)
    00067 {
    00068   q63_t sum = 0;                                 /* Temporary result storage */
    00069   uint32_t blkCnt;                               /* loop counter */
    00070
    00071
    00072 #ifndef ARM_MATH_CM0
    00073
    00074 /* Run the below code for Cortex-M4 and Cortex-M3 */
    00075
    00076   /*loop Unrolling */
    00077   blkCnt = blockSize >> 2u;
    00078
    00079   /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.
    00080    ** a second loop below computes the remaining 1 to 3 samples. */
    00081   while(blkCnt > 0u)
    00082   {
    00083     /* C = A[0]* B[0] + A[1]* B[1] + A[2]* B[2] + .....+ A[blockSize-1]* B[blockSize-1] */
    00084     /* Calculate dot product and then store the result in a temporary buffer. */
    00085     sum += ((q63_t) * pSrcA++ * *pSrcB++) >> 14u;
    00086     sum += ((q63_t) * pSrcA++ * *pSrcB++) >> 14u;
    00087     sum += ((q63_t) * pSrcA++ * *pSrcB++) >> 14u;
    00088     sum += ((q63_t) * pSrcA++ * *pSrcB++) >> 14u;
    00089
    00090     /* Decrement the loop counter */
    00091     blkCnt--;
    00092   }
    00093
    00094   /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
    00095    ** No loop unrolling is used. */
    00096   blkCnt = blockSize % 0x4u;
    00097
    00098 #else
    00099
    00100   /* Run the below code for Cortex-M0 */
    00101
    00102   /* Initialize blkCnt with number of samples */
    00103   blkCnt = blockSize;
    00104
    00105 #endif /* #ifndef ARM_MATH_CM0 */
    00106
    00107
    00108   while(blkCnt > 0u)
    00109   {
    00110     /* C = A[0]* B[0] + A[1]* B[1] + A[2]* B[2] + .....+ A[blockSize-1]* B[blockSize-1] */
    00111     /* Calculate dot product and then store the result in a temporary buffer. */
    00112     sum += ((q63_t) * pSrcA++ * *pSrcB++) >> 14u;
    00113
    00114     /* Decrement the loop counter */
    00115     blkCnt--;
    00116   }
    00117
    00118   /* Store the result in the destination buffer in 16.48 format */
    00119   *result = sum;
    00120 }
    00121

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