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# arm_dot_prod_q7.c

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    00001 /* ----------------------------------------------------------------------
    00002 * Copyright (C) 2010 ARM Limited. All rights reserved.
    00003 *
    00004 * $Date:        29. November 2010
    00005 * $Revision:    V1.0.3
    00006 *
    00007 * Project:      CMSIS DSP Library
    00008 * Title:        arm_dot_prod_q7.c
    00009 *
    00010 * Description:  Q7 dot product.
    00011 *
    00012 * Target Processor: Cortex-M4/Cortex-M3
    00013 *
    00014 * Version 1.0.3 2010/11/29
    00015 *    Re-organized the CMSIS folders and updated documentation.
    00016 *
    00017 * Version 1.0.2 2010/11/11
    00018 *    Documentation updated.
    00019 *
    00020 * Version 1.0.1 2010/10/05
    00021 *    Production release and review comments incorporated.
    00022 *
    00023 * Version 1.0.0 2010/09/20
    00024 *    Production release and review comments incorporated.
    00025 *
    00026 * Version 0.0.7  2010/06/10
    00027 *    Misra-C changes done
    00028 * -------------------------------------------------------------------- */
    00029
    00030 #include "arm_math.h"
    00031
    00058 void arm_dot_prod_q7(
    00059   q7_t * pSrcA,
    00060   q7_t * pSrcB,
    00061   uint32_t blockSize,
    00062   q31_t * result)
    00063 {
    00064   q31_t input1, input2;                          /* Temporary variables to store input */
    00065   q15_t in1, in2;                                /* Temporary variables to store input */
    00066   q31_t sum = 0;                                 /* Temporary variables to store output */
    00067   uint32_t blkCnt;                               /* loop counter */
    00068
    00069
    00070
    00071   /*loop Unrolling */
    00072   blkCnt = blockSize >> 2u;
    00073
    00074   /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.
    00075    ** a second loop below computes the remaining 1 to 3 samples. */
    00076   while(blkCnt > 0u)
    00077   {
    00078     /* Reading two inputs of SrcA buffer and packing */
    00079     in1 = (q15_t) * pSrcA++;
    00080     in2 = (q15_t) * pSrcA++;
    00081     input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
    00082
    00083     /* Reading two inputs of SrcB buffer and packing */
    00084     in1 = (q15_t) * pSrcB++;
    00085     in2 = (q15_t) * pSrcB++;
    00086     input2 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
    00087
    00088     /* C = A[0]* B[0] + A[1]* B[1] + A[2]* B[2] + .....+ A[blockSize-1]* B[blockSize-1] */
    00089     /* Perform Dot product of 2 packed inputs using SMLALD and store the result in a temporary variable. */
    00090     sum = __SMLAD(input1, input2, sum);
    00091
    00092     /* Reading two inputs of SrcA buffer and packing */
    00093     in1 = (q15_t) * pSrcA++;
    00094     in2 = (q15_t) * pSrcA++;
    00095     input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
    00096
    00097     /* Reading two inputs of SrcB buffer and packing */
    00098     in1 = (q15_t) * pSrcB++;
    00099     in2 = (q15_t) * pSrcB++;
    00100     input2 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
    00101
    00102     /* C = A[0]* B[0] + A[1]* B[1] + A[2]* B[2] + .....+ A[blockSize-1]* B[blockSize-1] */
    00103     /* Perform Dot product of 2 packed inputs using SMLALD and store the result in a temporary variable. */
    00104     sum = __SMLAD(input1, input2, sum);
    00105
    00106
    00107
    00108     /* Decrement the loop counter */
    00109     blkCnt--;
    00110   }
    00111
    00112   /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
    00113    ** No loop unrolling is used. */
    00114   blkCnt = blockSize % 0x4u;
    00115
    00116   while(blkCnt > 0u)
    00117   {
    00118     /* C = A[0]* B[0] + A[1]* B[1] + A[2]* B[2] + .....+ A[blockSize-1]* B[blockSize-1] */
    00119     /* Dot product and then store the results in a temporary buffer. */
    00120     sum = __SMLAD(*pSrcA++, *pSrcB++, sum);
    00121
    00122     /* Decrement the loop counter */
    00123     blkCnt--;
    00124   }
    00125
    00126   /* Store the result in the destination buffer in 18.14 format */
    00127   *result = sum;
    00128 }
    00129

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