lib/main/CMSIS/DSP/Source/BasicMathFunctions/arm_dot_prod_f32.c

   1 /* ----------------------------------------------------------------------
   2  * Project:      CMSIS DSP Library
   3  * Title:        arm_dot_prod_f32.c
   4  * Description:  Floating-point dot product
   5  *
   6  * $Date:        27. January 2017
   7  * $Revision:    V.1.5.1
   8  *
   9  * Target Processor: Cortex-M cores
  10  * -------------------------------------------------------------------- */
  11 /*
  12  * Copyright (C) 2010-2017 ARM Limited or its affiliates. All rights reserved.
  13  *
  14  * SPDX-License-Identifier: Apache-2.0
  15  *
  16  * Licensed under the Apache License, Version 2.0 (the License); you may
  17  * not use this file except in compliance with the License.
  18  * You may obtain a copy of the License at
  19  *
  20  * www.apache.org/licenses/LICENSE-2.0
  21  *
  22  * Unless required by applicable law or agreed to in writing, software
  23  * distributed under the License is distributed on an AS IS BASIS, WITHOUT
  24  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  25  * See the License for the specific language governing permissions and
  26  * limitations under the License.
  27  */
  28
  29 #include "arm_math.h"
  30
  31 /**
  32  * @ingroup groupMath
  33  */
  34
  35 /**
  36  * @defgroup dot_prod Vector Dot Product
  37  *
  38  * Computes the dot product of two vectors.
  39  * The vectors are multiplied element-by-element and then summed.
  40  *
  41  * <pre>
  42  *     sum = pSrcA[0]*pSrcB[0] + pSrcA[1]*pSrcB[1] + ... + pSrcA[blockSize-1]*pSrcB[blockSize-1]
  43  * </pre>
  44  *
  45  * There are separate functions for floating-point, Q7, Q15, and Q31 data types.
  46  */
  47
  48 /**
  49  * @addtogroup dot_prod
  50  * @{
  51  */
  52
  53 /**
  54  * @brief Dot product of floating-point vectors.
  55  * @param[in]       *pSrcA points to the first input vector
  56  * @param[in]       *pSrcB points to the second input vector
  57  * @param[in]       blockSize number of samples in each vector
  58  * @param[out]      *result output result returned here
  59  * @return none.
  60  */
  61
  62
  63 void arm_dot_prod_f32(
  64   float32_t * pSrcA,
  65   float32_t * pSrcB,
  66   uint32_t blockSize,
  67   float32_t * result)
  68 {
  69   float32_t sum = 0.0f;                          /* Temporary result storage */
  70   uint32_t blkCnt;                               /* loop counter */
  71
  72
  73 #if defined (ARM_MATH_DSP)
  74
  75 /* Run the below code for Cortex-M4 and Cortex-M3 */
  76   /*loop Unrolling */
  77   blkCnt = blockSize >> 2U;
  78
  79   /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.
  80    ** a second loop below computes the remaining 1 to 3 samples. */
  81   while (blkCnt > 0U)
  82   {
  83     /* C = A[0]* B[0] + A[1]* B[1] + A[2]* B[2] + .....+ A[blockSize-1]* B[blockSize-1] */
  84     /* Calculate dot product and then store the result in a temporary buffer */
  85     sum += (*pSrcA++) * (*pSrcB++);
  86     sum += (*pSrcA++) * (*pSrcB++);
  87     sum += (*pSrcA++) * (*pSrcB++);
  88     sum += (*pSrcA++) * (*pSrcB++);
  89
  90     /* Decrement the loop counter */
  91     blkCnt--;
  92   }
  93
  94   /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
  95    ** No loop unrolling is used. */
  96   blkCnt = blockSize % 0x4U;
  97
  98 #else
  99
 100   /* Run the below code for Cortex-M0 */
 101
 102   /* Initialize blkCnt with number of samples */
 103   blkCnt = blockSize;
 104
 105 #endif /* #if defined (ARM_MATH_DSP) */
 106
 107
 108   while (blkCnt > 0U)
 109   {
 110     /* C = A[0]* B[0] + A[1]* B[1] + A[2]* B[2] + .....+ A[blockSize-1]* B[blockSize-1] */
 111     /* Calculate dot product and then store the result in a temporary buffer. */
 112     sum += (*pSrcA++) * (*pSrcB++);
 113
 114     /* Decrement the loop counter */
 115     blkCnt--;
 116   }
 117   /* Store the result back in the destination buffer */
 118   *result = sum;
 119 }
 120
 121 /**
 122  * @} end of dot_prod group
 123  */