summaryrefslogtreecommitdiff
path: root/fw/midi-dials/Drivers/CMSIS/NN/Source/NNSupportFunctions/arm_nn_mult_q15.c
blob: de7668b93dd0d6e7286808554fce8fb5a72f937c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
/*
 * Copyright (C) 2010-2018 Arm Limited or its affiliates. All rights reserved.
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Licensed under the Apache License, Version 2.0 (the License); you may
 * not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an AS IS BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/* ----------------------------------------------------------------------
 * Project:      CMSIS NN Library
 * Title:        arm_nn_mult_q15.c
 * Description:  Q15 vector multiplication with variable output shifts
 *
 * $Date:        13. July 2018
 * $Revision:    V.1.0.0
 *
 * Target Processor:  Cortex-M cores
 *
 * -------------------------------------------------------------------- */

#include "arm_nnfunctions.h"

/**    
 * @ingroup groupSupport    
 */

/**
 * @addtogroup NNBasicMath
 * @{
 */


/**
 * @brief           Q7 vector multiplication with variable output shifts
 * @param[in]       *pSrcA        pointer to the first input vector
 * @param[in]       *pSrcB        pointer to the second input vector
 * @param[out]      *pDst         pointer to the output vector
 * @param[in]       out_shift     amount of right-shift for output
 * @param[in]       blockSize     number of samples in each vector
 * @return none.
 *
 * <b>Scaling and Overflow Behavior:</b>
 * \par
 * The function uses saturating arithmetic.
 * Results outside of the allowable Q15 range [0x8000 0x7FFF] will be saturated.
 */

void arm_nn_mult_q15(
  q15_t * pSrcA,
  q15_t * pSrcB,
  q15_t * pDst,
  const uint16_t out_shift,
  uint32_t blockSize)
{
  uint32_t blkCnt;                               /* loop counters */

#if defined (ARM_MATH_DSP)

/* Run the below code for Cortex-M4 and Cortex-M3 */
  q31_t inA1, inA2, inB1, inB2;                  /* temporary input variables */
  q15_t out1, out2, out3, out4;                  /* temporary output variables */
  q31_t mul1, mul2, mul3, mul4;                  /* temporary variables */

  /* loop Unrolling */
  blkCnt = blockSize >> 2U;

  /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.
   ** a second loop below computes the remaining 1 to 3 samples. */
  while (blkCnt > 0U)
  {
    /* read two samples at a time from sourceA */
    inA1 = *__SIMD32(pSrcA)++;
    /* read two samples at a time from sourceB */
    inB1 = *__SIMD32(pSrcB)++;
    /* read two samples at a time from sourceA */
    inA2 = *__SIMD32(pSrcA)++;
    /* read two samples at a time from sourceB */
    inB2 = *__SIMD32(pSrcB)++;

    /* multiply mul = sourceA * sourceB */
    mul1 = (q31_t) ((q15_t) (inA1 >> 16) * (q15_t) (inB1 >> 16));
    mul2 = (q31_t) ((q15_t) inA1 * (q15_t) inB1);
    mul3 = (q31_t) ((q15_t) (inA2 >> 16) * (q15_t) (inB2 >> 16));
    mul4 = (q31_t) ((q15_t) inA2 * (q15_t) inB2);

    /* saturate result to 16 bit */
    out1 = (q15_t) __SSAT((mul1 + NN_ROUND(out_shift)) >> out_shift, 16);
    out2 = (q15_t) __SSAT((mul2 + NN_ROUND(out_shift)) >> out_shift, 16);
    out3 = (q15_t) __SSAT((mul3 + NN_ROUND(out_shift)) >> out_shift, 16);
    out4 = (q15_t) __SSAT((mul4 + NN_ROUND(out_shift)) >> out_shift, 16);

    /* store the result */
#ifndef ARM_MATH_BIG_ENDIAN

    *__SIMD32(pDst)++ = __PKHBT(out2, out1, 16);
    *__SIMD32(pDst)++ = __PKHBT(out4, out3, 16);

#else

    *__SIMD32(pDst)++ = __PKHBT(out2, out1, 16);
    *__SIMD32(pDst)++ = __PKHBT(out4, out3, 16);

#endif /* #ifndef ARM_MATH_BIG_ENDIAN */

    /* Decrement the blockSize loop counter */
    blkCnt--;
  }

  /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
   ** No loop unrolling is used. */
  blkCnt = blockSize % 0x4U;

#else

  /* Run the below code for Cortex-M0 */

  /* Initialize blkCnt with number of samples */
  blkCnt = blockSize;

#endif /* #if defined (ARM_MATH_DSP) */


  while (blkCnt > 0U)
  {
    /* C = A * B */
    /* Multiply the inputs and store the result in the destination buffer */
    *pDst++ = (q15_t) __SSAT((((q31_t) (*pSrcA++) * (*pSrcB++) + NN_ROUND(out_shift)) >> out_shift), 16);

    /* Decrement the blockSize loop counter */
    blkCnt--;
  }
}

/**
 * @} end of NNBasicMath group
 */