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git.gir.st - tmk_keyboard.git/blob - tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/StatisticsFunctions/arm_max_q15.c
1 /* ----------------------------------------------------------------------
2 * Copyright (C) 2010-2013 ARM Limited. All rights reserved.
4 * $Date: 17. January 2013
7 * Project: CMSIS DSP Library
10 * Description: Maximum value of a Q15 vector.
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 * ---------------------------------------------------------------------------- */
54 * @brief Maximum value of a Q15 vector.
55 * @param[in] *pSrc points to the input vector
56 * @param[in] blockSize length of the input vector
57 * @param[out] *pResult maximum value returned here
58 * @param[out] *pIndex index of maximum value returned here
68 #ifndef ARM_MATH_CM0_FAMILY
70 /* Run the below code for Cortex-M4 and Cortex-M3 */
71 q15_t maxVal1
, maxVal2
, out
; /* Temporary variables to store the output value. */
72 uint32_t blkCnt
, outIndex
, count
; /* loop counter */
74 /* Initialise the count value. */
76 /* Initialise the index value to zero. */
78 /* Load first input value that act as reference value for comparision */
82 blkCnt
= (blockSize
- 1u) >> 2u;
84 /* Run the below code for Cortex-M4 and Cortex-M3 */
87 /* Initialize maxVal to the next consecutive values one by one */
92 /* compare for the maximum value */
95 /* Update the maximum value and its index */
97 outIndex
= count
+ 1u;
102 /* compare for the maximum value */
105 /* Update the maximum value and its index */
107 outIndex
= count
+ 2u;
112 /* compare for the maximum value */
115 /* Update the maximum value and its index */
117 outIndex
= count
+ 3u;
120 /* compare for the maximum value */
123 /* Update the maximum value and its index */
125 outIndex
= count
+ 4u;
130 /* Decrement the loop counter */
134 /* if (blockSize - 1u) is not multiple of 4 */
135 blkCnt
= (blockSize
- 1u) % 4u;
139 /* Run the below code for Cortex-M0 */
140 q15_t maxVal1
, out
; /* Temporary variables to store the output value. */
141 uint32_t blkCnt
, outIndex
; /* loop counter */
143 blkCnt
= (blockSize
- 1u);
145 /* Initialise the index value to zero. */
147 /* Load first input value that act as reference value for comparision */
150 #endif /* #ifndef ARM_MATH_CM0_FAMILY */
154 /* Initialize maxVal to the next consecutive values one by one */
157 /* compare for the maximum value */
160 /* Update the maximum value and it's index */
162 outIndex
= blockSize
- blkCnt
;
164 /* Decrement the loop counter */
169 /* Store the maximum value and its index into destination pointers */
175 * @} end of Max group