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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_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_mat_sub_q31.c
10 * Description: Q31 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 Q31 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 Q31 range [0x80000000 0x7FFFFFFF] will be saturated.
67 arm_status
arm_mat_sub_q31(
68 const arm_matrix_instance_q31
* pSrcA
,
69 const arm_matrix_instance_q31
* pSrcB
,
70 arm_matrix_instance_q31
* pDst
)
72 q31_t
*pIn1
= pSrcA
->pData
; /* input data matrix pointer A */
73 q31_t
*pIn2
= pSrcB
->pData
; /* input data matrix pointer B */
74 q31_t
*pOut
= pDst
->pData
; /* output data matrix pointer */
75 q31_t inA1
, inB1
; /* temporary variables */
77 #ifndef ARM_MATH_CM0_FAMILY
79 q31_t inA2
, inB2
; /* temporary variables */
80 q31_t out1
, out2
; /* temporary variables */
82 #endif // #ifndef ARM_MATH_CM0_FAMILY
84 uint32_t numSamples
; /* total number of elements in the matrix */
85 uint32_t blkCnt
; /* loop counters */
86 arm_status status
; /* status of matrix subtraction */
89 #ifdef ARM_MATH_MATRIX_CHECK
90 /* Check for matrix mismatch condition */
91 if((pSrcA
->numRows
!= pSrcB
->numRows
) ||
92 (pSrcA
->numCols
!= pSrcB
->numCols
) ||
93 (pSrcA
->numRows
!= pDst
->numRows
) || (pSrcA
->numCols
!= pDst
->numCols
))
95 /* Set status as ARM_MATH_SIZE_MISMATCH */
96 status
= ARM_MATH_SIZE_MISMATCH
;
101 /* Total number of samples in the input matrix */
102 numSamples
= (uint32_t) pSrcA
->numRows
* pSrcA
->numCols
;
104 #ifndef ARM_MATH_CM0_FAMILY
106 /* Run the below code for Cortex-M4 and Cortex-M3 */
109 blkCnt
= numSamples
>> 2u;
111 /* First part of the processing with loop unrolling. Compute 4 outputs at a time.
112 ** a second loop below computes the remaining 1 to 3 samples. */
115 /* C(m,n) = A(m,n) - B(m,n) */
116 /* Subtract, saturate and then store the results in the destination buffer. */
117 /* Read values from source A */
120 /* Read values from source B */
123 /* Read values from source A */
126 /* Subtract and saturate */
127 out1
= __QSUB(inA1
, inB1
);
129 /* Read values from source B */
132 /* Read values from source A */
135 /* Subtract and saturate */
136 out2
= __QSUB(inA2
, inB2
);
138 /* Read values from source B */
141 /* Store result in destination */
145 /* Read values from source A */
148 /* Read values from source B */
151 /* Subtract and saturate */
152 out1
= __QSUB(inA1
, inB1
);
154 /* Subtract and saturate */
155 out2
= __QSUB(inA2
, inB2
);
157 /* Store result in destination */
161 /* update pointers to process next samples */
166 /* Decrement the loop counter */
170 /* If the numSamples is not a multiple of 4, compute any remaining output samples here.
171 ** No loop unrolling is used. */
172 blkCnt
= numSamples
% 0x4u
;
176 /* Run the below code for Cortex-M0 */
178 /* Initialize blkCnt with number of samples */
181 #endif /* #ifndef ARM_MATH_CM0_FAMILY */
185 /* C(m,n) = A(m,n) - B(m,n) */
186 /* Subtract, saturate and then store the results in the destination buffer. */
190 inA1
= __QSUB(inA1
, inB1
);
194 /* Decrement the loop counter */
198 /* Set status as ARM_MATH_SUCCESS */
199 status
= ARM_MATH_SUCCESS
;
202 /* Return to application */
207 * @} end of MatrixSub group