Subversion Repositories FuelGauge

Rev

Blame | Last modification | View Log | Download | RSS feed

  1. /* ----------------------------------------------------------------------
  2.  * Project:      CMSIS DSP Library
  3.  * Title:        arm_mult_q7.c
  4.  * Description:  Q7 vector multiplication
  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.  * @addtogroup BasicMult
  37.  * @{
  38.  */
  39.  
  40. /**
  41.  * @brief           Q7 vector multiplication
  42.  * @param[in]       *pSrcA points to the first input vector
  43.  * @param[in]       *pSrcB points to the second input vector
  44.  * @param[out]      *pDst points to the output vector
  45.  * @param[in]       blockSize number of samples in each vector
  46.  * @return none.
  47.  *
  48.  * <b>Scaling and Overflow Behavior:</b>
  49.  * \par
  50.  * The function uses saturating arithmetic.
  51.  * Results outside of the allowable Q7 range [0x80 0x7F] will be saturated.
  52.  */
  53.  
  54. void arm_mult_q7(
  55.   q7_t * pSrcA,
  56.   q7_t * pSrcB,
  57.   q7_t * pDst,
  58.   uint32_t blockSize)
  59. {
  60.   uint32_t blkCnt;                               /* loop counters */
  61.  
  62. #if defined (ARM_MATH_DSP)
  63.  
  64. /* Run the below code for Cortex-M4 and Cortex-M3 */
  65.   q7_t out1, out2, out3, out4;                   /* Temporary variables to store the product */
  66.  
  67.   /* loop Unrolling */
  68.   blkCnt = blockSize >> 2U;
  69.  
  70.   /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.
  71.    ** a second loop below computes the remaining 1 to 3 samples. */
  72.   while (blkCnt > 0U)
  73.   {
  74.     /* C = A * B */
  75.     /* Multiply the inputs and store the results in temporary variables */
  76.     out1 = (q7_t) __SSAT((((q15_t) (*pSrcA++) * (*pSrcB++)) >> 7), 8);
  77.     out2 = (q7_t) __SSAT((((q15_t) (*pSrcA++) * (*pSrcB++)) >> 7), 8);
  78.     out3 = (q7_t) __SSAT((((q15_t) (*pSrcA++) * (*pSrcB++)) >> 7), 8);
  79.     out4 = (q7_t) __SSAT((((q15_t) (*pSrcA++) * (*pSrcB++)) >> 7), 8);
  80.  
  81.     /* Store the results of 4 inputs in the destination buffer in single cycle by packing */
  82.     *__SIMD32(pDst)++ = __PACKq7(out1, out2, out3, out4);
  83.  
  84.     /* Decrement the blockSize loop counter */
  85.     blkCnt--;
  86.   }
  87.  
  88.   /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
  89.    ** No loop unrolling is used. */
  90.   blkCnt = blockSize % 0x4U;
  91.  
  92. #else
  93.  
  94.   /* Run the below code for Cortex-M0 */
  95.  
  96.   /* Initialize blkCnt with number of samples */
  97.   blkCnt = blockSize;
  98.  
  99. #endif /* #if defined (ARM_MATH_DSP) */
  100.  
  101.  
  102.   while (blkCnt > 0U)
  103.   {
  104.     /* C = A * B */
  105.     /* Multiply the inputs and store the result in the destination buffer */
  106.     *pDst++ = (q7_t) __SSAT((((q15_t) (*pSrcA++) * (*pSrcB++)) >> 7), 8);
  107.  
  108.     /* Decrement the blockSize loop counter */
  109.     blkCnt--;
  110.   }
  111. }
  112.  
  113. /**
  114.  * @} end of BasicMult group
  115.  */
  116.