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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_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_conj_q31.c
10 * Description: Q31 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
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 * @addtogroup cmplx_conj
52 * @brief Q31 complex conjugate.
53 * @param *pSrc points to the input vector
54 * @param *pDst points to the output vector
55 * @param numSamples number of complex samples in each vector
58 * <b>Scaling and Overflow Behavior:</b>
60 * The function uses saturating arithmetic.
61 * The Q31 value -1 (0x80000000) will be saturated to the maximum allowable positive value 0x7FFFFFFF.
64 void arm_cmplx_conj_q31(
69 uint32_t blkCnt
; /* loop counter */
70 q31_t in
; /* Input value */
72 #ifndef ARM_MATH_CM0_FAMILY
74 /* Run the below code for Cortex-M4 and Cortex-M3 */
75 q31_t inR1
, inR2
, inR3
, inR4
; /* Temporary real variables */
76 q31_t inI1
, inI2
, inI3
, inI4
; /* Temporary imaginary variables */
79 blkCnt
= numSamples
>> 2u;
81 /* First part of the processing with loop unrolling. Compute 4 outputs at a time.
82 ** a second loop below computes the remaining 1 to 3 samples. */
85 /* C[0]+jC[1] = A[0]+ j (-1) A[1] */
86 /* Calculate Complex Conjugate and then store the results in the destination buffer. */
87 /* Saturated to 0x7fffffff if the input is -1(0x80000000) */
88 /* read real input sample */
90 /* store real input sample */
93 /* read imaginary input sample */
96 /* read real input sample */
98 /* store real input sample */
101 /* read imaginary input sample */
104 /* negate imaginary input sample */
105 inI1
= __QSUB(0, inI1
);
107 /* read real input sample */
109 /* store real input sample */
112 /* read imaginary input sample */
115 /* negate imaginary input sample */
116 inI2
= __QSUB(0, inI2
);
118 /* read real input sample */
120 /* store real input sample */
123 /* negate imaginary input sample */
124 inI3
= __QSUB(0, inI3
);
126 /* store imaginary input sample */
129 /* store imaginary input samples */
132 /* negate imaginary input sample */
133 inI4
= __QSUB(0, inI4
);
135 /* store imaginary input samples */
138 /* increment source pointer by 8 to proecess next samples */
141 /* store imaginary input samples */
145 /* increment destination pointer by 8 to process next samples */
148 /* Decrement the loop counter */
152 /* If the numSamples is not a multiple of 4, compute any remaining output samples here.
153 ** No loop unrolling is used. */
154 blkCnt
= numSamples
% 0x4u
;
158 /* Run the below code for Cortex-M0 */
162 #endif /* #ifndef ARM_MATH_CM0_FAMILY */
166 /* C[0]+jC[1] = A[0]+ j (-1) A[1] */
167 /* Calculate Complex Conjugate and then store the results in the destination buffer. */
168 /* Saturated to 0x7fffffff if the input is -1(0x80000000) */
171 *pDst
++ = (in
== INT32_MIN
) ? INT32_MAX
: -in
;
173 /* Decrement the loop counter */
179 * @} end of cmplx_conj group