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git.gir.st - tmk_keyboard.git/blob - tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/ComplexMathFunctions/arm_cmplx_conj_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_conj_f32.c
10 * Description: Floating-point complex conjugate.
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
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18 * notice, this list of conditions and the following disclaimer.
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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,
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39 * ---------------------------------------------------------------------------- */
43 * @ingroup groupCmplxMath
47 * @defgroup cmplx_conj Complex Conjugate
49 * Conjugates 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 * and the data in each array is stored in an interleaved fashion
55 * (real, imag, real, imag, ...).
56 * Each array has a total of <code>2*numSamples</code> values.
57 * The underlying algorithm is used:
60 * for(n=0; n<numSamples; n++) {
61 * pDst[(2*n)+0)] = pSrc[(2*n)+0]; // real part
62 * pDst[(2*n)+1)] = -pSrc[(2*n)+1]; // imag part
66 * There are separate functions for floating-point, Q15, and Q31 data types.
70 * @addtogroup cmplx_conj
75 * @brief Floating-point complex conjugate.
76 * @param *pSrc points to the input vector
77 * @param *pDst points to the output vector
78 * @param numSamples number of complex samples in each vector
82 void arm_cmplx_conj_f32(
87 uint32_t blkCnt
; /* loop counter */
89 #ifndef ARM_MATH_CM0_FAMILY
91 /* Run the below code for Cortex-M4 and Cortex-M3 */
92 float32_t inR1
, inR2
, inR3
, inR4
;
93 float32_t inI1
, inI2
, inI3
, inI4
;
96 blkCnt
= numSamples
>> 2u;
98 /* First part of the processing with loop unrolling. Compute 4 outputs at a time.
99 ** a second loop below computes the remaining 1 to 3 samples. */
102 /* C[0]+jC[1] = A[0]+ j (-1) A[1] */
103 /* Calculate Complex Conjugate and then store the results in the destination buffer. */
104 /* read real input samples */
106 /* store real samples to destination */
115 /* read imaginary input samples */
119 /* conjugate input */
122 /* read imaginary input samples */
125 /* conjugate input */
128 /* read imaginary input samples */
131 /* conjugate input */
134 /* store imaginary samples to destination */
138 /* conjugate input */
141 /* store imaginary samples to destination */
144 /* increment source pointer by 8 to process next sampels */
147 /* store imaginary sample to destination */
150 /* increment destination pointer by 8 to store 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 /* realOut + j (imagOut) = realIn + j (-1) imagIn */
171 /* Calculate Complex Conjugate and then store the results in the destination buffer. */
175 /* Decrement the loop counter */
181 * @} end of cmplx_conj group