arm_mat_sub_f32.c

00001 /* ----------------------------------------------------------------------
00002  * Project:      CMSIS DSP Library
00003  * Title:        arm_mat_sub_f32.c
00004  * Description:  Floating-point matrix subtraction
00005  *
00006  * $Date:        27. January 2017
00007  * $Revision:    V.1.5.1
00008  *
00009  * Target Processor: Cortex-M cores
00010  * -------------------------------------------------------------------- */
00011 /*
00012  * Copyright (C) 2010-2017 ARM Limited or its affiliates. All rights reserved.
00013  *
00014  * SPDX-License-Identifier: Apache-2.0
00015  *
00016  * Licensed under the Apache License, Version 2.0 (the License); you may
00017  * not use this file except in compliance with the License.
00018  * You may obtain a copy of the License at
00019  *
00020  * www.apache.org/licenses/LICENSE-2.0
00021  *
00022  * Unless required by applicable law or agreed to in writing, software
00023  * distributed under the License is distributed on an AS IS BASIS, WITHOUT
00024  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00025  * See the License for the specific language governing permissions and
00026  * limitations under the License.
00027  */
00028 
00029 #include "arm_math.h"
00030 
00031 /**
00032  * @ingroup groupMatrix
00033  */
00034 
00035 /**
00036  * @defgroup MatrixSub Matrix Subtraction
00037  *
00038  * Subtract two matrices.
00039  * \image html MatrixSubtraction.gif "Subraction of two 3 x 3 matrices"
00040  *
00041  * The functions check to make sure that
00042  * <code>pSrcA</code>, <code>pSrcB</code>, and <code>pDst</code> have the same
00043  * number of rows and columns.
00044  */
00045 
00046 /**
00047  * @addtogroup MatrixSub
00048  * @{
00049  */
00050 
00051 /**
00052  * @brief Floating-point matrix subtraction
00053  * @param[in]       *pSrcA points to the first input matrix structure
00054  * @param[in]       *pSrcB points to the second input matrix structure
00055  * @param[out]      *pDst points to output matrix structure
00056  * @return          The function returns either
00057  * <code>ARM_MATH_SIZE_MISMATCH</code> or <code>ARM_MATH_SUCCESS</code> based on the outcome of size checking.
00058  */
00059 
00060 arm_status arm_mat_sub_f32(
00061   const arm_matrix_instance_f32 * pSrcA,
00062   const arm_matrix_instance_f32 * pSrcB,
00063   arm_matrix_instance_f32 * pDst)
00064 {
00065   float32_t *pIn1 = pSrcA->pData;                /* input data matrix pointer A */
00066   float32_t *pIn2 = pSrcB->pData;                /* input data matrix pointer B */
00067   float32_t *pOut = pDst->pData;                 /* output data matrix pointer  */
00068 
00069 #if defined (ARM_MATH_DSP)
00070 
00071   float32_t inA1, inA2, inB1, inB2, out1, out2;  /* temporary variables */
00072 
00073 #endif //      #if defined (ARM_MATH_DSP)
00074 
00075   uint32_t numSamples;                           /* total number of elements in the matrix  */
00076   uint32_t blkCnt;                               /* loop counters */
00077   arm_status status;                             /* status of matrix subtraction */
00078 
00079 #ifdef ARM_MATH_MATRIX_CHECK
00080   /* Check for matrix mismatch condition */
00081   if ((pSrcA->numRows != pSrcB->numRows) ||
00082      (pSrcA->numCols != pSrcB->numCols) ||
00083      (pSrcA->numRows != pDst->numRows) || (pSrcA->numCols != pDst->numCols))
00084   {
00085     /* Set status as ARM_MATH_SIZE_MISMATCH */
00086     status = ARM_MATH_SIZE_MISMATCH;
00087   }
00088   else
00089 #endif /*    #ifdef ARM_MATH_MATRIX_CHECK    */
00090   {
00091     /* Total number of samples in the input matrix */
00092     numSamples = (uint32_t) pSrcA->numRows * pSrcA->numCols;
00093 
00094 #if defined (ARM_MATH_DSP)
00095 
00096     /* Run the below code for Cortex-M4 and Cortex-M3 */
00097 
00098     /* Loop Unrolling */
00099     blkCnt = numSamples >> 2U;
00100 
00101     /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.
00102      ** a second loop below computes the remaining 1 to 3 samples. */
00103     while (blkCnt > 0U)
00104     {
00105       /* C(m,n) = A(m,n) - B(m,n) */
00106       /* Subtract and then store the results in the destination buffer. */
00107       /* Read values from source A */
00108       inA1 = pIn1[0];
00109 
00110       /* Read values from source B */
00111       inB1 = pIn2[0];
00112 
00113       /* Read values from source A */
00114       inA2 = pIn1[1];
00115 
00116       /* out = sourceA - sourceB */
00117       out1 = inA1 - inB1;
00118 
00119       /* Read values from source B */
00120       inB2 = pIn2[1];
00121 
00122       /* Read values from source A */
00123       inA1 = pIn1[2];
00124 
00125       /* out = sourceA - sourceB */
00126       out2 = inA2 - inB2;
00127 
00128       /* Read values from source B */
00129       inB1 = pIn2[2];
00130 
00131       /* Store result in destination */
00132       pOut[0] = out1;
00133       pOut[1] = out2;
00134 
00135       /* Read values from source A */
00136       inA2 = pIn1[3];
00137 
00138       /* Read values from source B */
00139       inB2 = pIn2[3];
00140 
00141       /* out = sourceA - sourceB */
00142       out1 = inA1 - inB1;
00143 
00144 
00145       /* out = sourceA - sourceB */
00146       out2 = inA2 - inB2;
00147 
00148       /* Store result in destination */
00149       pOut[2] = out1;
00150 
00151       /* Store result in destination */
00152       pOut[3] = out2;
00153 
00154 
00155       /* update pointers to process next sampels */
00156       pIn1 += 4U;
00157       pIn2 += 4U;
00158       pOut += 4U;
00159 
00160       /* Decrement the loop counter */
00161       blkCnt--;
00162     }
00163 
00164     /* If the numSamples is not a multiple of 4, compute any remaining output samples here.
00165      ** No loop unrolling is used. */
00166     blkCnt = numSamples % 0x4U;
00167 
00168 #else
00169 
00170     /* Run the below code for Cortex-M0 */
00171 
00172     /* Initialize blkCnt with number of samples */
00173     blkCnt = numSamples;
00174 
00175 #endif /* #if defined (ARM_MATH_DSP) */
00176 
00177     while (blkCnt > 0U)
00178     {
00179       /* C(m,n) = A(m,n) - B(m,n) */
00180       /* Subtract and then store the results in the destination buffer. */
00181       *pOut++ = (*pIn1++) - (*pIn2++);
00182 
00183       /* Decrement the loop counter */
00184       blkCnt--;
00185     }
00186 
00187     /* Set status as ARM_MATH_SUCCESS */
00188     status = ARM_MATH_SUCCESS;
00189   }
00190 
00191   /* Return to application */
00192   return (status);
00193 }
00194 
00195 /**
00196  * @} end of MatrixSub group
00197  */
00198