1 /* ----------------------------------------------------------------------
2  * Project:      CMSIS DSP Library
3  * Title:        arm_mat_sub_f64.c
4  * Description:  Floating-point matrix subtraction
5  *
6  * $Date:        23 April 2021
7  * $Revision:    V1.9.0
8  *
9  * Target Processor: Cortex-M and Cortex-A cores
10  * -------------------------------------------------------------------- */
11 /*
12  * Copyright (C) 2010-2021 ARM Limited or its affiliates. All rights reserved.
13  *
14  * SPDX-License-Identifier: Apache-2.0
15  *
16  * Licensed under the Apache License, Version 2.0 (the License); you may
17  * not use this file except in compliance with the License.
18  * You may obtain a copy of the License at
19  *
20  * www.apache.org/licenses/LICENSE-2.0
21  *
22  * Unless required by applicable law or agreed to in writing, software
23  * distributed under the License is distributed on an AS IS BASIS, WITHOUT
24  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
25  * See the License for the specific language governing permissions and
26  * limitations under the License.
27  */
28 
29 #include "dsp/matrix_functions.h"
30 
31 /**
32   @ingroup groupMatrix
33  */
34 
35 /**
36   @defgroup MatrixSub Matrix Subtraction
37 
38   Subtract two matrices.
39   \image html MatrixSubtraction.gif "Subraction of two 3 x 3 matrices"
40 
41   The functions check to make sure that
42   <code>pSrcA</code>, <code>pSrcB</code>, and <code>pDst</code> have the same
43   number of rows and columns.
44  */
45 
46 /**
47   @addtogroup MatrixSub
48   @{
49  */
50 
51 /**
52   @brief         Floating-point matrix subtraction.
53   @param[in]     pSrcA      points to the first input matrix structure
54   @param[in]     pSrcB      points to the second input matrix structure
55   @param[out]    pDst       points to output matrix structure
56   @return        execution status
57                    - \ref ARM_MATH_SUCCESS       : Operation successful
58                    - \ref ARM_MATH_SIZE_MISMATCH : Matrix size check failed
59  */
60 
arm_mat_sub_f64(const arm_matrix_instance_f64 * pSrcA,const arm_matrix_instance_f64 * pSrcB,arm_matrix_instance_f64 * pDst)61 arm_status arm_mat_sub_f64(
62   const arm_matrix_instance_f64 * pSrcA,
63   const arm_matrix_instance_f64 * pSrcB,
64         arm_matrix_instance_f64 * pDst)
65 {
66   float64_t *pInA = pSrcA->pData;                /* input data matrix pointer A */
67   float64_t *pInB = pSrcB->pData;                /* input data matrix pointer B */
68   float64_t *pOut = pDst->pData;                 /* output data matrix pointer */
69 
70   uint64_t numSamples;                           /* total number of elements in the matrix */
71   uint64_t blkCnt;                               /* loop counters */
72   arm_status status;                             /* status of matrix subtraction */
73 
74 #ifdef ARM_MATH_MATRIX_CHECK
75 
76   /* Check for matrix mismatch condition */
77   if ((pSrcA->numRows != pSrcB->numRows) ||
78       (pSrcA->numCols != pSrcB->numCols) ||
79       (pSrcA->numRows != pDst->numRows)  ||
80       (pSrcA->numCols != pDst->numCols)    )
81   {
82     /* Set status as ARM_MATH_SIZE_MISMATCH */
83     status = ARM_MATH_SIZE_MISMATCH;
84   }
85   else
86 
87 #endif /* #ifdef ARM_MATH_MATRIX_CHECK */
88 
89   {
90     /* Total number of samples in input matrix */
91     numSamples = (uint64_t) pSrcA->numRows * pSrcA->numCols;
92 
93 #if defined (ARM_MATH_LOOPUNROLL)
94 
95     /* Loop unrolling: Compute 4 outputs at a time */
96     blkCnt = numSamples >> 2U;
97 
98     while (blkCnt > 0U)
99     {
100       /* C(m,n) = A(m,n) - B(m,n) */
101 
102       /* Subtract and store result in destination buffer. */
103       *pOut++ = (*pInA++) - (*pInB++);
104       *pOut++ = (*pInA++) - (*pInB++);
105       *pOut++ = (*pInA++) - (*pInB++);
106       *pOut++ = (*pInA++) - (*pInB++);
107 
108       /* Decrement loop counter */
109       blkCnt--;
110     }
111 
112     /* Loop unrolling: Compute remaining outputs */
113     blkCnt = numSamples % 0x4U;
114 
115 #else
116 
117     /* Initialize blkCnt with number of samples */
118     blkCnt = numSamples;
119 
120 #endif /* #if defined (ARM_MATH_LOOPUNROLL) */
121 
122     while (blkCnt > 0U)
123     {
124       /* C(m,n) = A(m,n) - B(m,n) */
125 
126       /* Subtract and store result in destination buffer. */
127       *pOut++ = (*pInA++) - (*pInB++);
128 
129       /* Decrement loop counter */
130       blkCnt--;
131     }
132 
133     /* Set status as ARM_MATH_SUCCESS */
134     status = ARM_MATH_SUCCESS;
135   }
136 
137   /* Return to application */
138   return (status);
139 }
140 
141 /**
142   @} end of MatrixSub group
143  */
144