summaryrefslogtreecommitdiff
path: root/platform/CMSIS/DSP_Lib/Source/ComplexMathFunctions/arm_cmplx_mag_q31.c
blob: 984a51770b93dff47803e2a1d18da74932733fe6 (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
/* ----------------------------------------------------------------------    
* Copyright (C) 2010-2014 ARM Limited. All rights reserved.    
*    
* $Date:        12. March 2014
* $Revision: 	V1.4.4
*    
* Project: 	    CMSIS DSP Library    
* Title:		arm_cmplx_mag_q31.c    
*    
* Description:	Q31 complex magnitude    
*    
* 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 cmplx_mag        
 * @{        
 */

/**        
 * @brief  Q31 complex magnitude        
 * @param  *pSrc points to the complex input vector        
 * @param  *pDst points to the real output vector        
 * @param  numSamples number of complex samples in the input vector        
 * @return none.        
 *        
 * <b>Scaling and Overflow Behavior:</b>        
 * \par        
 * The function implements 1.31 by 1.31 multiplications and finally output is converted into 2.30 format.        
 * Input down scaling is not required.        
 */

void arm_cmplx_mag_q31(
  q31_t * pSrc,
  q31_t * pDst,
  uint32_t numSamples)
{
  q31_t real, imag;                              /* Temporary variables to hold input values */
  q31_t acc0, acc1;                              /* Accumulators */
  uint32_t blkCnt;                               /* loop counter */

#ifndef ARM_MATH_CM0_FAMILY

  /* Run the below code for Cortex-M4 and Cortex-M3 */
  q31_t real1, real2, imag1, imag2;              /* Temporary variables to hold input values */
  q31_t out1, out2, out3, out4;                  /* Accumulators */
  q63_t mul1, mul2, mul3, mul4;                  /* Temporary variables */


  /*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)
  {
    /* read complex input from source buffer */
    real1 = pSrc[0];
    imag1 = pSrc[1];
    real2 = pSrc[2];
    imag2 = pSrc[3];

    /* calculate power of input values */
    mul1 = (q63_t) real1 *real1;
    mul2 = (q63_t) imag1 *imag1;
    mul3 = (q63_t) real2 *real2;
    mul4 = (q63_t) imag2 *imag2;

    /* get the result to 3.29 format */
    out1 = (q31_t) (mul1 >> 33);
    out2 = (q31_t) (mul2 >> 33);
    out3 = (q31_t) (mul3 >> 33);
    out4 = (q31_t) (mul4 >> 33);

    /* add real and imaginary accumulators */
    out1 = out1 + out2;
    out3 = out3 + out4;

    /* read complex input from source buffer */
    real1 = pSrc[4];
    imag1 = pSrc[5];
    real2 = pSrc[6];
    imag2 = pSrc[7];

    /* calculate square root */
    arm_sqrt_q31(out1, &pDst[0]);

    /* calculate power of input values */
    mul1 = (q63_t) real1 *real1;

    /* calculate square root */
    arm_sqrt_q31(out3, &pDst[1]);

    /* calculate power of input values */
    mul2 = (q63_t) imag1 *imag1;
    mul3 = (q63_t) real2 *real2;
    mul4 = (q63_t) imag2 *imag2;

    /* get the result to 3.29 format */
    out1 = (q31_t) (mul1 >> 33);
    out2 = (q31_t) (mul2 >> 33);
    out3 = (q31_t) (mul3 >> 33);
    out4 = (q31_t) (mul4 >> 33);

    /* add real and imaginary accumulators */
    out1 = out1 + out2;
    out3 = out3 + out4;

    /* calculate square root */
    arm_sqrt_q31(out1, &pDst[2]);

    /* increment destination by 8 to process next samples */
    pSrc += 8u;

    /* calculate square root */
    arm_sqrt_q31(out3, &pDst[3]);

    /* increment destination by 4 to process next samples */
    pDst += 4u;

    /* Decrement the 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;

#else

  /* Run the below code for Cortex-M0 */
  blkCnt = numSamples;

#endif /* #ifndef ARM_MATH_CM0_FAMILY */

  while(blkCnt > 0u)
  {
    /* C[0] = sqrt(A[0] * A[0] + A[1] * A[1]) */
    real = *pSrc++;
    imag = *pSrc++;
    acc0 = (q31_t) (((q63_t) real * real) >> 33);
    acc1 = (q31_t) (((q63_t) imag * imag) >> 33);
    /* store the result in 2.30 format in the destination buffer. */
    arm_sqrt_q31(acc0 + acc1, pDst++);

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

/**        
 * @} end of cmplx_mag group        
 */