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git.gir.st - tmk_keyboard.git/blob - tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/MatrixFunctions/arm_mat_sub_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_mat_sub_q15.c
10 * Description: Q15 Matrix 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 * -------------------------------------------------------------------- */
44 * @ingroup groupMatrix
48 * @addtogroup MatrixSub
53 * @brief Q15 matrix subtraction.
54 * @param[in] *pSrcA points to the first input matrix structure
55 * @param[in] *pSrcB points to the second input matrix structure
56 * @param[out] *pDst points to output matrix structure
57 * @return The function returns either
58 * <code>ARM_MATH_SIZE_MISMATCH</code> or <code>ARM_MATH_SUCCESS</code> based on the outcome of size checking.
60 * <b>Scaling and Overflow Behavior:</b>
62 * The function uses saturating arithmetic.
63 * Results outside of the allowable Q15 range [0x8000 0x7FFF] will be saturated.
66 arm_status
arm_mat_sub_q15(
67 const arm_matrix_instance_q15
* pSrcA
,
68 const arm_matrix_instance_q15
* pSrcB
,
69 arm_matrix_instance_q15
* pDst
)
71 q15_t
*pInA
= pSrcA
->pData
; /* input data matrix pointer A */
72 q15_t
*pInB
= pSrcB
->pData
; /* input data matrix pointer B */
73 q15_t
*pOut
= pDst
->pData
; /* output data matrix pointer */
74 uint32_t numSamples
; /* total number of elements in the matrix */
75 uint32_t blkCnt
; /* loop counters */
76 arm_status status
; /* status of matrix subtraction */
79 #ifdef ARM_MATH_MATRIX_CHECK
82 /* Check for matrix mismatch condition */
83 if((pSrcA
->numRows
!= pSrcB
->numRows
) ||
84 (pSrcA
->numCols
!= pSrcB
->numCols
) ||
85 (pSrcA
->numRows
!= pDst
->numRows
) || (pSrcA
->numCols
!= pDst
->numCols
))
87 /* Set status as ARM_MATH_SIZE_MISMATCH */
88 status
= ARM_MATH_SIZE_MISMATCH
;
91 #endif /* #ifdef ARM_MATH_MATRIX_CHECK */
94 /* Total number of samples in the input matrix */
95 numSamples
= (uint32_t) pSrcA
->numRows
* pSrcA
->numCols
;
97 #ifndef ARM_MATH_CM0_FAMILY
99 /* Run the below code for Cortex-M4 and Cortex-M3 */
101 /* Apply loop unrolling */
102 blkCnt
= numSamples
>> 2u;
104 /* First part of the processing with loop unrolling. Compute 4 outputs at a time.
105 ** a second loop below computes the remaining 1 to 3 samples. */
108 /* C(m,n) = A(m,n) - B(m,n) */
109 /* Subtract, Saturate and then store the results in the destination buffer. */
110 *__SIMD32(pOut
)++ = __QSUB16(*__SIMD32(pInA
)++, *__SIMD32(pInB
)++);
111 *__SIMD32(pOut
)++ = __QSUB16(*__SIMD32(pInA
)++, *__SIMD32(pInB
)++);
113 /* Decrement the loop counter */
117 /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
118 ** No loop unrolling is used. */
119 blkCnt
= numSamples
% 0x4u
;
123 /* C(m,n) = A(m,n) - B(m,n) */
124 /* Subtract and then store the results in the destination buffer. */
125 *pOut
++ = (q15_t
) __QSUB16(*pInA
++, *pInB
++);
127 /* Decrement the loop counter */
133 /* Run the below code for Cortex-M0 */
135 /* Initialize blkCnt with number of samples */
140 /* C(m,n) = A(m,n) - B(m,n) */
141 /* Subtract and then store the results in the destination buffer. */
142 *pOut
++ = (q15_t
) __SSAT(((q31_t
) * pInA
++ - *pInB
++), 16);
144 /* Decrement the loop counter */
148 #endif /* #ifndef ARM_MATH_CM0_FAMILY */
150 /* Set status as ARM_MATH_SUCCESS */
151 status
= ARM_MATH_SUCCESS
;
154 /* Return to application */
159 * @} end of MatrixSub group