summaryrefslogtreecommitdiff
path: root/Drivers/CMSIS/DSP/Source/ComplexMathFunctions/arm_cmplx_mult_real_q15.c
blob: b6d3cb810dcc23d97b144e02488444adaa23dc8e (plain) (blame)
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
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
/* ----------------------------------------------------------------------
 * Project:      CMSIS DSP Library
 * Title:        arm_cmplx_mult_real_q15.c
 * Description:  Q15 complex by real multiplication
 *
 * $Date:        18. March 2019
 * $Revision:    V1.6.0
 *
 * Target Processor: Cortex-M cores
 * -------------------------------------------------------------------- */
/*
 * Copyright (C) 2010-2019 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.
 */

#include "arm_math.h"

/**
  @ingroup groupCmplxMath
 */

/**
  @addtogroup CmplxByRealMult
  @{
 */

/**
  @brief         Q15 complex-by-real multiplication.
  @param[in]     pSrcCmplx   points to complex input vector
  @param[in]     pSrcReal    points to real input vector
  @param[out]    pCmplxDst   points to complex output vector
  @param[in]     numSamples  number of samples in each vector
  @return        none

  @par           Scaling and Overflow Behavior
                   The function uses saturating arithmetic.
                   Results outside of the allowable Q15 range [0x8000 0x7FFF] are saturated.
 */

void arm_cmplx_mult_real_q15(
  const q15_t * pSrcCmplx,
  const q15_t * pSrcReal,
        q15_t * pCmplxDst,
        uint32_t numSamples)
{
        uint32_t blkCnt;                               /* Loop counter */
        q15_t in;                                      /* Temporary variable */

#if defined (ARM_MATH_LOOPUNROLL)

#if defined (ARM_MATH_DSP)
        q31_t inA1, inA2;                              /* Temporary variables to hold input data */
        q31_t inB1;                                    /* Temporary variables to hold input data */
        q15_t out1, out2, out3, out4;                  /* Temporary variables to hold output data */
        q31_t mul1, mul2, mul3, mul4;                  /* Temporary variables to hold intermediate data */
#endif

  /* Loop unrolling: Compute 4 outputs at a time */
  blkCnt = numSamples >> 2U;

  while (blkCnt > 0U)
  {
    /* C[2 * i    ] = A[2 * i    ] * B[i]. */
    /* C[2 * i + 1] = A[2 * i + 1] * B[i]. */

#if defined (ARM_MATH_DSP)
    /* read 2 complex numbers both real and imaginary from complex input buffer */
    inA1 = read_q15x2_ia ((q15_t **) &pSrcCmplx);
    inA2 = read_q15x2_ia ((q15_t **) &pSrcCmplx);
    /* read 2 real values at a time from real input buffer */
    inB1 = read_q15x2_ia ((q15_t **) &pSrcReal);

    /* multiply complex number with real numbers */
#ifndef ARM_MATH_BIG_ENDIAN
    mul1 = (q31_t) ((q15_t) (inA1)       * (q15_t) (inB1));
    mul2 = (q31_t) ((q15_t) (inA1 >> 16) * (q15_t) (inB1));
    mul3 = (q31_t) ((q15_t) (inA2)       * (q15_t) (inB1 >> 16));
    mul4 = (q31_t) ((q15_t) (inA2 >> 16) * (q15_t) (inB1 >> 16));
#else
    mul2 = (q31_t) ((q15_t) (inA1 >> 16) * (q15_t) (inB1 >> 16));
    mul1 = (q31_t) ((q15_t) inA1         * (q15_t) (inB1 >> 16));
    mul4 = (q31_t) ((q15_t) (inA2 >> 16) * (q15_t) inB1);
    mul3 = (q31_t) ((q15_t) inA2         * (q15_t) inB1);
#endif /* #ifndef ARM_MATH_BIG_ENDIAN */

    /* saturate the result */
    out1 = (q15_t) __SSAT(mul1 >> 15U, 16);
    out2 = (q15_t) __SSAT(mul2 >> 15U, 16);
    out3 = (q15_t) __SSAT(mul3 >> 15U, 16);
    out4 = (q15_t) __SSAT(mul4 >> 15U, 16);

    /* pack real and imaginary outputs and store them to destination */
    write_q15x2_ia (&pCmplxDst, __PKHBT(out1, out2, 16));
    write_q15x2_ia (&pCmplxDst, __PKHBT(out3, out4, 16));

    inA1 = read_q15x2_ia ((q15_t **) &pSrcCmplx);
    inA2 = read_q15x2_ia ((q15_t **) &pSrcCmplx);
    inB1 = read_q15x2_ia ((q15_t **) &pSrcReal);

#ifndef ARM_MATH_BIG_ENDIAN
    mul1 = (q31_t) ((q15_t) (inA1)       * (q15_t) (inB1));
    mul2 = (q31_t) ((q15_t) (inA1 >> 16) * (q15_t) (inB1));
    mul3 = (q31_t) ((q15_t) (inA2)       * (q15_t) (inB1 >> 16));
    mul4 = (q31_t) ((q15_t) (inA2 >> 16) * (q15_t) (inB1 >> 16));
#else
    mul2 = (q31_t) ((q15_t) (inA1 >> 16) * (q15_t) (inB1 >> 16));
    mul1 = (q31_t) ((q15_t) inA1         * (q15_t) (inB1 >> 16));
    mul4 = (q31_t) ((q15_t) (inA2 >> 16) * (q15_t) inB1);
    mul3 = (q31_t) ((q15_t) inA2 * (q15_t) inB1);
#endif /* #ifndef ARM_MATH_BIG_ENDIAN */

    out1 = (q15_t) __SSAT(mul1 >> 15U, 16);
    out2 = (q15_t) __SSAT(mul2 >> 15U, 16);
    out3 = (q15_t) __SSAT(mul3 >> 15U, 16);
    out4 = (q15_t) __SSAT(mul4 >> 15U, 16);

    write_q15x2_ia (&pCmplxDst, __PKHBT(out1, out2, 16));
    write_q15x2_ia (&pCmplxDst, __PKHBT(out3, out4, 16));
#else
    in = *pSrcReal++;
    *pCmplxDst++ = (q15_t) __SSAT((((q31_t) *pSrcCmplx++ * in) >> 15), 16);
    *pCmplxDst++ = (q15_t) __SSAT((((q31_t) *pSrcCmplx++ * in) >> 15), 16);

    in = *pSrcReal++;
    *pCmplxDst++ = (q15_t) __SSAT((((q31_t) *pSrcCmplx++ * in) >> 15), 16);
    *pCmplxDst++ = (q15_t) __SSAT((((q31_t) *pSrcCmplx++ * in) >> 15), 16);

    in = *pSrcReal++;
    *pCmplxDst++ = (q15_t) __SSAT((((q31_t) *pSrcCmplx++ * in) >> 15), 16);
    *pCmplxDst++ = (q15_t) __SSAT((((q31_t) *pSrcCmplx++ * in) >> 15), 16);

    in = *pSrcReal++;
    *pCmplxDst++ = (q15_t) __SSAT((((q31_t) *pSrcCmplx++ * in) >> 15), 16);
    *pCmplxDst++ = (q15_t) __SSAT((((q31_t) *pSrcCmplx++ * in) >> 15), 16);
#endif

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

  /* Loop unrolling: Compute remaining outputs */
  blkCnt = numSamples % 0x4U;

#else

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

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

  while (blkCnt > 0U)
  {
    /* C[2 * i    ] = A[2 * i    ] * B[i]. */
    /* C[2 * i + 1] = A[2 * i + 1] * B[i]. */

    in = *pSrcReal++;
    /* store the result in the destination buffer. */
    *pCmplxDst++ = (q15_t) __SSAT((((q31_t) *pSrcCmplx++ * in) >> 15), 16);
    *pCmplxDst++ = (q15_t) __SSAT((((q31_t) *pSrcCmplx++ * in) >> 15), 16);

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

}

/**
  @} end of CmplxByRealMult group
 */