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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_squared_f32.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_squared_f32.c
10 * Description: Floating-point complex magnitude squared.
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 * ---------------------------------------------------------------------------- */
43 * @ingroup groupCmplxMath
47 * @defgroup cmplx_mag_squared Complex Magnitude Squared
49 * Computes the magnitude squared of the elements of a complex data vector.
51 * The <code>pSrc</code> points to the source data and
52 * <code>pDst</code> points to the where the result should be written.
53 * <code>numSamples</code> specifies the number of complex samples
54 * in the input array and the data is stored in an interleaved fashion
55 * (real, imag, real, imag, ...).
56 * The input array has a total of <code>2*numSamples</code> values;
57 * the output array has a total of <code>numSamples</code> values.
59 * The underlying algorithm is used:
62 * for(n=0; n<numSamples; n++) {
63 * pDst[n] = pSrc[(2*n)+0]^2 + pSrc[(2*n)+1]^2;
67 * There are separate functions for floating-point, Q15, and Q31 data types.
71 * @addtogroup cmplx_mag_squared
77 * @brief Floating-point complex magnitude squared
78 * @param[in] *pSrc points to the complex input vector
79 * @param[out] *pDst points to the real output vector
80 * @param[in] numSamples number of complex samples in the input vector
84 void arm_cmplx_mag_squared_f32(
89 float32_t real
, imag
; /* Temporary variables to store real and imaginary values */
90 uint32_t blkCnt
; /* loop counter */
92 #ifndef ARM_MATH_CM0_FAMILY
93 float32_t real1
, real2
, real3
, real4
; /* Temporary variables to hold real values */
94 float32_t imag1
, imag2
, imag3
, imag4
; /* Temporary variables to hold imaginary values */
95 float32_t mul1
, mul2
, mul3
, mul4
; /* Temporary variables */
96 float32_t mul5
, mul6
, mul7
, mul8
; /* Temporary variables */
97 float32_t out1
, out2
, out3
, out4
; /* Temporary variables to hold output values */
100 blkCnt
= numSamples
>> 2u;
102 /* First part of the processing with loop unrolling. Compute 4 outputs at a time.
103 ** a second loop below computes the remaining 1 to 3 samples. */
106 /* C[0] = (A[0] * A[0] + A[1] * A[1]) */
107 /* read real input sample from source buffer */
109 /* read imaginary input sample from source buffer */
112 /* calculate power of real value */
113 mul1
= real1
* real1
;
115 /* read real input sample from source buffer */
118 /* calculate power of imaginary value */
119 mul2
= imag1
* imag1
;
121 /* read imaginary input sample from source buffer */
124 /* calculate power of real value */
125 mul3
= real2
* real2
;
127 /* read real input sample from source buffer */
130 /* calculate power of imaginary value */
131 mul4
= imag2
* imag2
;
133 /* read imaginary input sample from source buffer */
136 /* calculate power of real value */
137 mul5
= real3
* real3
;
138 /* calculate power of imaginary value */
139 mul6
= imag3
* imag3
;
141 /* read real input sample from source buffer */
144 /* accumulate real and imaginary powers */
147 /* read imaginary input sample from source buffer */
150 /* accumulate real and imaginary powers */
153 /* calculate power of real value */
154 mul7
= real4
* real4
;
155 /* calculate power of imaginary value */
156 mul8
= imag4
* imag4
;
158 /* store output to destination */
161 /* accumulate real and imaginary powers */
164 /* store output to destination */
167 /* accumulate real and imaginary powers */
170 /* store output to destination */
173 /* increment destination pointer by 8 to process next samples */
176 /* store output to destination */
179 /* increment destination pointer by 4 to process next samples */
182 /* Decrement the loop counter */
186 /* If the numSamples is not a multiple of 4, compute any remaining output samples here.
187 ** No loop unrolling is used. */
188 blkCnt
= numSamples
% 0x4u
;
192 /* Run the below code for Cortex-M0 */
196 #endif /* #ifndef ARM_MATH_CM0_FAMILY */
200 /* C[0] = (A[0] * A[0] + A[1] * A[1]) */
204 /* out = (real * real) + (imag * imag) */
205 /* store the result in the destination buffer. */
206 *pDst
++ = (real
* real
) + (imag
* imag
);
208 /* Decrement the loop counter */
214 * @} end of cmplx_mag_squared group