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git.gir.st - tmk_keyboard.git/blob - tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/ComplexMathFunctions/arm_cmplx_mag_q31.c
1 /* ----------------------------------------------------------------------
2 * Copyright (C) 2010-2013 ARM Limited. All rights reserved.
4 * $Date: 17. January 2013
7 * Project: CMSIS DSP Library
8 * Title: arm_cmplx_mag_q31.c
10 * Description: Q31 complex magnitude
12 * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions
17 * - Redistributions of source code must retain the above copyright
18 * notice, this list of conditions and the following disclaimer.
19 * - Redistributions in binary form must reproduce the above copyright
20 * notice, this list of conditions and the following disclaimer in
21 * the documentation and/or other materials provided with the
23 * - Neither the name of ARM LIMITED nor the names of its contributors
24 * may be used to endorse or promote products derived from this
25 * software without specific prior written permission.
27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
28 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
29 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
30 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
31 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
32 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
33 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
34 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
35 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
37 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
38 * POSSIBILITY OF SUCH DAMAGE.
39 * ---------------------------------------------------------------------------- */
44 * @ingroup groupCmplxMath
48 * @addtogroup cmplx_mag
53 * @brief Q31 complex magnitude
54 * @param *pSrc points to the complex input vector
55 * @param *pDst points to the real output vector
56 * @param numSamples number of complex samples in the input vector
59 * <b>Scaling and Overflow Behavior:</b>
61 * The function implements 1.31 by 1.31 multiplications and finally output is converted into 2.30 format.
62 * Input down scaling is not required.
65 void arm_cmplx_mag_q31(
70 q31_t real
, imag
; /* Temporary variables to hold input values */
71 q31_t acc0
, acc1
; /* Accumulators */
72 uint32_t blkCnt
; /* loop counter */
74 #ifndef ARM_MATH_CM0_FAMILY
76 /* Run the below code for Cortex-M4 and Cortex-M3 */
77 q31_t real1
, real2
, imag1
, imag2
; /* Temporary variables to hold input values */
78 q31_t out1
, out2
, out3
, out4
; /* Accumulators */
79 q63_t mul1
, mul2
, mul3
, mul4
; /* Temporary variables */
83 blkCnt
= numSamples
>> 2u;
85 /* First part of the processing with loop unrolling. Compute 4 outputs at a time.
86 ** a second loop below computes the remaining 1 to 3 samples. */
89 /* read complex input from source buffer */
95 /* calculate power of input values */
96 mul1
= (q63_t
) real1
*real1
;
97 mul2
= (q63_t
) imag1
*imag1
;
98 mul3
= (q63_t
) real2
*real2
;
99 mul4
= (q63_t
) imag2
*imag2
;
101 /* get the result to 3.29 format */
102 out1
= (q31_t
) (mul1
>> 33);
103 out2
= (q31_t
) (mul2
>> 33);
104 out3
= (q31_t
) (mul3
>> 33);
105 out4
= (q31_t
) (mul4
>> 33);
107 /* add real and imaginary accumulators */
111 /* read complex input from source buffer */
117 /* calculate square root */
118 arm_sqrt_q31(out1
, &pDst
[0]);
120 /* calculate power of input values */
121 mul1
= (q63_t
) real1
*real1
;
123 /* calculate square root */
124 arm_sqrt_q31(out3
, &pDst
[1]);
126 /* calculate power of input values */
127 mul2
= (q63_t
) imag1
*imag1
;
128 mul3
= (q63_t
) real2
*real2
;
129 mul4
= (q63_t
) imag2
*imag2
;
131 /* get the result to 3.29 format */
132 out1
= (q31_t
) (mul1
>> 33);
133 out2
= (q31_t
) (mul2
>> 33);
134 out3
= (q31_t
) (mul3
>> 33);
135 out4
= (q31_t
) (mul4
>> 33);
137 /* add real and imaginary accumulators */
141 /* calculate square root */
142 arm_sqrt_q31(out1
, &pDst
[2]);
144 /* increment destination by 8 to process next samples */
147 /* calculate square root */
148 arm_sqrt_q31(out3
, &pDst
[3]);
150 /* increment destination by 4 to process next samples */
153 /* Decrement the loop counter */
157 /* If the numSamples is not a multiple of 4, compute any remaining output samples here.
158 ** No loop unrolling is used. */
159 blkCnt
= numSamples
% 0x4u
;
163 /* Run the below code for Cortex-M0 */
166 #endif /* #ifndef ARM_MATH_CM0_FAMILY */
170 /* C[0] = sqrt(A[0] * A[0] + A[1] * A[1]) */
173 acc0
= (q31_t
) (((q63_t
) real
* real
) >> 33);
174 acc1
= (q31_t
) (((q63_t
) imag
* imag
) >> 33);
175 /* store the result in 2.30 format in the destination buffer. */
176 arm_sqrt_q31(acc0
+ acc1
, pDst
++);
178 /* Decrement the loop counter */
184 * @} end of cmplx_mag group