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git.gir.st - tmk_keyboard.git/blob - tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/BasicMathFunctions/arm_offset_q15.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_offset_q15.c
10 * Description: Q15 vector offset.
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 * -------------------------------------------------------------------- */
53 * @brief Adds a constant offset to a Q15 vector.
54 * @param[in] *pSrc points to the input vector
55 * @param[in] offset is the offset to be added
56 * @param[out] *pDst points to the output vector
57 * @param[in] blockSize number of samples in the vector
60 * <b>Scaling and Overflow Behavior:</b>
62 * The function uses saturating arithmetic.
63 * Results outside of the allowable Q15 range [0x8000 0x7FFF] are saturated.
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 offset_packed
; /* Offset packed to 32 bit */
81 blkCnt
= blockSize
>> 2u;
83 /* Offset is packed to 32 bit in order to use SIMD32 for addition */
84 offset_packed
= __PKHBT(offset
, offset
, 16);
86 /* First part of the processing with loop unrolling. Compute 4 outputs at a time.
87 ** a second loop below computes the remaining 1 to 3 samples. */
91 /* Add offset and then store the results in the destination buffer, 2 samples at a time. */
92 *__SIMD32(pDst
)++ = __QADD16(*__SIMD32(pSrc
)++, offset_packed
);
93 *__SIMD32(pDst
)++ = __QADD16(*__SIMD32(pSrc
)++, offset_packed
);
95 /* Decrement the loop counter */
99 /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
100 ** No loop unrolling is used. */
101 blkCnt
= blockSize
% 0x4u
;
106 /* Add offset and then store the results in the destination buffer. */
107 *pDst
++ = (q15_t
) __QADD16(*pSrc
++, offset
);
109 /* Decrement the loop counter */
115 /* Run the below code for Cortex-M0 */
117 /* Initialize blkCnt with number of samples */
123 /* Add offset and then store the results in the destination buffer. */
124 *pDst
++ = (q15_t
) __SSAT(((q31_t
) * pSrc
++ + offset
), 16);
126 /* Decrement the loop counter */
130 #endif /* #ifndef ARM_MATH_CM0_FAMILY */
135 * @} end of offset group