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git.gir.st - tmk_keyboard.git/blob - tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/BasicMathFunctions/arm_sub_f32.c
1 /* ----------------------------------------------------------------------
2 * Copyright (C) 2010-2013 ARM Limited. All rights reserved.
4 * $Date: 17. January 2013
7 * Project: CMSIS DSP Library
10 * Description: Floating-point vector subtraction.
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 * ---------------------------------------------------------------------------- */
48 * @defgroup BasicSub Vector Subtraction
50 * Element-by-element subtraction of two vectors.
53 * pDst[n] = pSrcA[n] - pSrcB[n], 0 <= n < blockSize.
56 * There are separate functions for floating-point, Q7, Q15, and Q31 data types.
60 * @addtogroup BasicSub
66 * @brief Floating-point vector subtraction.
67 * @param[in] *pSrcA points to the first input vector
68 * @param[in] *pSrcB points to the second input vector
69 * @param[out] *pDst points to the output vector
70 * @param[in] blockSize number of samples in each vector
80 uint32_t blkCnt
; /* loop counter */
82 #ifndef ARM_MATH_CM0_FAMILY
84 /* Run the below code for Cortex-M4 and Cortex-M3 */
85 float32_t inA1
, inA2
, inA3
, inA4
; /* temporary variables */
86 float32_t inB1
, inB2
, inB3
, inB4
; /* temporary variables */
89 blkCnt
= blockSize
>> 2u;
91 /* First part of the processing with loop unrolling. Compute 4 outputs at a time.
92 ** a second loop below computes the remaining 1 to 3 samples. */
96 /* Subtract and then store the results in the destination buffer. */
97 /* Read 4 input samples from sourceA and sourceB */
107 /* dst = srcA - srcB */
108 /* subtract and store the result */
110 *(pDst
+ 1) = inA2
- inB2
;
111 *(pDst
+ 2) = inA3
- inB3
;
112 *(pDst
+ 3) = inA4
- inB4
;
115 /* Update pointers to process next sampels */
120 /* Decrement the loop counter */
124 /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
125 ** No loop unrolling is used. */
126 blkCnt
= blockSize
% 0x4u
;
130 /* Run the below code for Cortex-M0 */
132 /* Initialize blkCnt with number of samples */
135 #endif /* #ifndef ARM_MATH_CM0_FAMILY */
140 /* Subtract and then store the results in the destination buffer. */
141 *pDst
++ = (*pSrcA
++) - (*pSrcB
++);
143 /* Decrement the loop counter */
149 * @} end of BasicSub group