summaryrefslogtreecommitdiff
path: root/platform/CMSIS/DSP_Lib/Source/ComplexMathFunctions/arm_cmplx_mult_real_q15.c
blob: d2cc66af9b7c1c9d59a3ba10f2937d20f1d6959f (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
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
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
/* ----------------------------------------------------------------------    
* Copyright (C) 2010-2014 ARM Limited. All rights reserved.    
*    
* $Date:        12. March 2014
* $Revision: 	V1.4.4
*    
* Project: 	    CMSIS DSP Library    
* Title:	    arm_cmplx_mult_real_q15.c    
*    
* Description:	Q15 complex by real multiplication    
*    
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
*  
* Redistribution and use in source and binary forms, with or without 
* modification, are permitted provided that the following conditions
* are met:
*   - Redistributions of source code must retain the above copyright
*     notice, this list of conditions and the following disclaimer.
*   - Redistributions in binary form must reproduce the above copyright
*     notice, this list of conditions and the following disclaimer in
*     the documentation and/or other materials provided with the 
*     distribution.
*   - Neither the name of ARM LIMITED nor the names of its contributors
*     may be used to endorse or promote products derived from this
*     software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE. 
* -------------------------------------------------------------------- */

#include "arm_math.h"

/**    
 * @ingroup groupCmplxMath    
 */

/**    
 * @addtogroup CmplxByRealMult    
 * @{    
 */


/**    
 * @brief  Q15 complex-by-real multiplication    
 * @param[in]  *pSrcCmplx points to the complex input vector    
 * @param[in]  *pSrcReal points to the real input vector    
 * @param[out]  *pCmplxDst points to the complex output vector    
 * @param[in]  numSamples 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_cmplx_mult_real_q15(
  q15_t * pSrcCmplx,
  q15_t * pSrcReal,
  q15_t * pCmplxDst,
  uint32_t numSamples)
{
  q15_t in;                                      /* Temporary variable to store input value */

#ifndef ARM_MATH_CM0_FAMILY

  /* Run the below code for Cortex-M4 and Cortex-M3 */
  uint32_t blkCnt;                               /* loop counters */
  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 */

  /* loop Unrolling */
  blkCnt = numSamples >> 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)
  {
    /* C[2 * i] = A[2 * i] * B[i].            */
    /* C[2 * i + 1] = A[2 * i + 1] * B[i].        */
    /* read complex number both real and imaginary from complex input buffer */
    inA1 = *__SIMD32(pSrcCmplx)++;
    /* read two real values at a time from real input buffer */
    inB1 = *__SIMD32(pSrcReal)++;
    /* read complex number both real and imaginary from complex input buffer */
    inA2 = *__SIMD32(pSrcCmplx)++;

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

    inA1 = *__SIMD32(pSrcCmplx)++;
    inB1 = *__SIMD32(pSrcReal)++;
    inA2 = *__SIMD32(pSrcCmplx)++;

#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);

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

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

  /* If the numSamples is not a multiple of 4, compute any remaining output samples here.    
   ** No loop unrolling is used. */
  blkCnt = numSamples % 0x4u;

  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 the numSamples loop counter */
    blkCnt--;
  }

#else

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

  while(numSamples > 0u)
  {
    /* realOut = realA * realB.            */
    /* imagOut = imagA * realB.                */
    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 the numSamples loop counter */
    numSamples--;
  }

#endif /* #ifndef ARM_MATH_CM0_FAMILY */

}

/**    
 * @} end of CmplxByRealMult group    
 */