lib/main/CMSIS/DSP/Source/MatrixFunctions/arm_mat_sub_f32.c

   1 /* ----------------------------------------------------------------------
   2  * Project:      CMSIS DSP Library
   3  * Title:        arm_mat_sub_f32.c
   4  * Description:  Floating-point matrix subtraction
   5  *
   6  * $Date:        27. January 2017
   7  * $Revision:    V.1.5.1
   8  *
   9  * Target Processor: Cortex-M cores
  10  * -------------------------------------------------------------------- */
  11 /*
  12  * Copyright (C) 2010-2017 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 "arm_math.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              The function returns either
  57  * <code>ARM_MATH_SIZE_MISMATCH</code> or <code>ARM_MATH_SUCCESS</code> based on the outcome of size checking.
  58  */
  59
  60 arm_status arm_mat_sub_f32(
  61   const arm_matrix_instance_f32 * pSrcA,
  62   const arm_matrix_instance_f32 * pSrcB,
  63   arm_matrix_instance_f32 * pDst)
  64 {
  65   float32_t *pIn1 = pSrcA->pData;                /* input data matrix pointer A */
  66   float32_t *pIn2 = pSrcB->pData;                /* input data matrix pointer B */
  67   float32_t *pOut = pDst->pData;                 /* output data matrix pointer  */
  68
  69 #if defined (ARM_MATH_DSP)
  70
  71   float32_t inA1, inA2, inB1, inB2, out1, out2;  /* temporary variables */
  72
  73 #endif //      #if defined (ARM_MATH_DSP)
  74
  75   uint32_t numSamples;                           /* total number of elements in the matrix  */
  76   uint32_t blkCnt;                               /* loop counters */
  77   arm_status status;                             /* status of matrix subtraction */
  78
  79 #ifdef ARM_MATH_MATRIX_CHECK
  80   /* Check for matrix mismatch condition */
  81   if ((pSrcA->numRows != pSrcB->numRows) ||
  82      (pSrcA->numCols != pSrcB->numCols) ||
  83      (pSrcA->numRows != pDst->numRows) || (pSrcA->numCols != pDst->numCols))
  84   {
  85     /* Set status as ARM_MATH_SIZE_MISMATCH */
  86     status = ARM_MATH_SIZE_MISMATCH;
  87   }
  88   else
  89 #endif /*    #ifdef ARM_MATH_MATRIX_CHECK    */
  90   {
  91     /* Total number of samples in the input matrix */
  92     numSamples = (uint32_t) pSrcA->numRows * pSrcA->numCols;
  93
  94 #if defined (ARM_MATH_DSP)
  95
  96     /* Run the below code for Cortex-M4 and Cortex-M3 */
  97
  98     /* Loop Unrolling */
  99     blkCnt = numSamples >> 2U;
 100
 101     /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.
 102      ** a second loop below computes the remaining 1 to 3 samples. */
 103     while (blkCnt > 0U)
 104     {
 105       /* C(m,n) = A(m,n) - B(m,n) */
 106       /* Subtract and then store the results in the destination buffer. */
 107       /* Read values from source A */
 108       inA1 = pIn1[0];
 109
 110       /* Read values from source B */
 111       inB1 = pIn2[0];
 112
 113       /* Read values from source A */
 114       inA2 = pIn1[1];
 115
 116       /* out = sourceA - sourceB */
 117       out1 = inA1 - inB1;
 118
 119       /* Read values from source B */
 120       inB2 = pIn2[1];
 121
 122       /* Read values from source A */
 123       inA1 = pIn1[2];
 124
 125       /* out = sourceA - sourceB */
 126       out2 = inA2 - inB2;
 127
 128       /* Read values from source B */
 129       inB1 = pIn2[2];
 130
 131       /* Store result in destination */
 132       pOut[0] = out1;
 133       pOut[1] = out2;
 134
 135       /* Read values from source A */
 136       inA2 = pIn1[3];
 137
 138       /* Read values from source B */
 139       inB2 = pIn2[3];
 140
 141       /* out = sourceA - sourceB */
 142       out1 = inA1 - inB1;
 143
 144
 145       /* out = sourceA - sourceB */
 146       out2 = inA2 - inB2;
 147
 148       /* Store result in destination */
 149       pOut[2] = out1;
 150
 151       /* Store result in destination */
 152       pOut[3] = out2;
 153
 154
 155       /* update pointers to process next sampels */
 156       pIn1 += 4U;
 157       pIn2 += 4U;
 158       pOut += 4U;
 159
 160       /* Decrement the loop counter */
 161       blkCnt--;
 162     }
 163
 164     /* If the numSamples is not a multiple of 4, compute any remaining output samples here.
 165      ** No loop unrolling is used. */
 166     blkCnt = numSamples % 0x4U;
 167
 168 #else
 169
 170     /* Run the below code for Cortex-M0 */
 171
 172     /* Initialize blkCnt with number of samples */
 173     blkCnt = numSamples;
 174
 175 #endif /* #if defined (ARM_MATH_DSP) */
 176
 177     while (blkCnt > 0U)
 178     {
 179       /* C(m,n) = A(m,n) - B(m,n) */
 180       /* Subtract and then store the results in the destination buffer. */
 181       *pOut++ = (*pIn1++) - (*pIn2++);
 182
 183       /* Decrement the loop counter */
 184       blkCnt--;
 185     }
 186
 187     /* Set status as ARM_MATH_SUCCESS */
 188     status = ARM_MATH_SUCCESS;
 189   }
 190
 191   /* Return to application */
 192   return (status);
 193 }
 194
 195 /**
 196  * @} end of MatrixSub group
 197  */