tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/MatrixFunctions/arm_mat_scale_f32.c

   1 /* ----------------------------------------------------------------------
   2 * Copyright (C) 2010-2013 ARM Limited. All rights reserved.
   3 *
   4 * $Date:        17. January 2013
   5 * $Revision:    V1.4.1
   6 *
   7 * Project:          CMSIS DSP Library
   8 * Title:        arm_mat_scale_f32.c
   9 *
  10 * Description:  Multiplies a floating-point matrix by a scalar.
  11 *
  12 * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
  13 *
  14 * Redistribution and use in source and binary forms, with or without
  15 * modification, are permitted provided that the following conditions
  16 * are met:
  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
  22 *     distribution.
  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.
  26 *
  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 * -------------------------------------------------------------------- */
  40
  41 #include "arm_math.h"
  42
  43 /**
  44  * @ingroup groupMatrix
  45  */
  46
  47 /**
  48  * @defgroup MatrixScale Matrix Scale
  49  *
  50  * Multiplies a matrix by a scalar.  This is accomplished by multiplying each element in the
  51  * matrix by the scalar.  For example:
  52  * \image html MatrixScale.gif "Matrix Scaling of a 3 x 3 matrix"
  53  *
  54  * The function checks to make sure that the input and output matrices are of the same size.
  55  *
  56  * In the fixed-point Q15 and Q31 functions, <code>scale</code> is represented by
  57  * a fractional multiplication <code>scaleFract</code> and an arithmetic shift <code>shift</code>.
  58  * The shift allows the gain of the scaling operation to exceed 1.0.
  59  * The overall scale factor applied to the fixed-point data is
  60  * <pre>
  61  *     scale = scaleFract * 2^shift.
  62  * </pre>
  63  */
  64
  65 /**
  66  * @addtogroup MatrixScale
  67  * @{
  68  */
  69
  70 /**
  71  * @brief Floating-point matrix scaling.
  72  * @param[in]       *pSrc points to input matrix structure
  73  * @param[in]       scale scale factor to be applied
  74  * @param[out]      *pDst points to output matrix structure
  75  * @return              The function returns either <code>ARM_MATH_SIZE_MISMATCH</code>
  76  * or <code>ARM_MATH_SUCCESS</code> based on the outcome of size checking.
  77  *
  78  */
  79
  80 arm_status arm_mat_scale_f32(
  81   const arm_matrix_instance_f32 * pSrc,
  82   float32_t scale,
  83   arm_matrix_instance_f32 * pDst)
  84 {
  85   float32_t *pIn = pSrc->pData;                  /* input data matrix pointer */
  86   float32_t *pOut = pDst->pData;                 /* output data matrix pointer */
  87   uint32_t numSamples;                           /* total number of elements in the matrix */
  88   uint32_t blkCnt;                               /* loop counters */
  89   arm_status status;                             /* status of matrix scaling     */
  90
  91 #ifndef ARM_MATH_CM0_FAMILY
  92
  93   float32_t in1, in2, in3, in4;                  /* temporary variables */
  94   float32_t out1, out2, out3, out4;              /* temporary variables */
  95
  96 #endif //      #ifndef ARM_MATH_CM0_FAMILY
  97
  98 #ifdef ARM_MATH_MATRIX_CHECK
  99   /* Check for matrix mismatch condition */
 100   if((pSrc->numRows != pDst->numRows) || (pSrc->numCols != pDst->numCols))
 101   {
 102     /* Set status as ARM_MATH_SIZE_MISMATCH */
 103     status = ARM_MATH_SIZE_MISMATCH;
 104   }
 105   else
 106 #endif /*    #ifdef ARM_MATH_MATRIX_CHECK    */
 107   {
 108     /* Total number of samples in the input matrix */
 109     numSamples = (uint32_t) pSrc->numRows * pSrc->numCols;
 110
 111 #ifndef ARM_MATH_CM0_FAMILY
 112
 113     /* Run the below code for Cortex-M4 and Cortex-M3 */
 114
 115     /* Loop Unrolling */
 116     blkCnt = numSamples >> 2;
 117
 118     /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.
 119      ** a second loop below computes the remaining 1 to 3 samples. */
 120     while(blkCnt > 0u)
 121     {
 122       /* C(m,n) = A(m,n) * scale */
 123       /* Scaling and results are stored in the destination buffer. */
 124       in1 = pIn[0];
 125       in2 = pIn[1];
 126       in3 = pIn[2];
 127       in4 = pIn[3];
 128
 129       out1 = in1 * scale;
 130       out2 = in2 * scale;
 131       out3 = in3 * scale;
 132       out4 = in4 * scale;
 133
 134
 135       pOut[0] = out1;
 136       pOut[1] = out2;
 137       pOut[2] = out3;
 138       pOut[3] = out4;
 139
 140       /* update pointers to process next sampels */
 141       pIn += 4u;
 142       pOut += 4u;
 143
 144       /* Decrement the numSamples loop counter */
 145       blkCnt--;
 146     }
 147
 148     /* If the numSamples is not a multiple of 4, compute any remaining output samples here.
 149      ** No loop unrolling is used. */
 150     blkCnt = numSamples % 0x4u;
 151
 152 #else
 153
 154     /* Run the below code for Cortex-M0 */
 155
 156     /* Initialize blkCnt with number of samples */
 157     blkCnt = numSamples;
 158
 159 #endif /* #ifndef ARM_MATH_CM0_FAMILY */
 160
 161     while(blkCnt > 0u)
 162     {
 163       /* C(m,n) = A(m,n) * scale */
 164       /* The results are stored in the destination buffer. */
 165       *pOut++ = (*pIn++) * scale;
 166
 167       /* Decrement the loop counter */
 168       blkCnt--;
 169     }
 170
 171     /* Set status as ARM_MATH_SUCCESS */
 172     status = ARM_MATH_SUCCESS;
 173   }
 174
 175   /* Return to application */
 176   return (status);
 177 }
 178
 179 /**
 180  * @} end of MatrixScale group
 181  */