tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/MatrixFunctions/arm_mat_scale_q15.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_q15.c
   9 *
  10 * Description:  Multiplies a Q15 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  * @addtogroup MatrixScale
  49  * @{
  50  */
  51
  52 /**
  53  * @brief Q15 matrix scaling.
  54  * @param[in]       *pSrc points to input matrix
  55  * @param[in]       scaleFract fractional portion of the scale factor
  56  * @param[in]       shift number of bits to shift the result by
  57  * @param[out]      *pDst points to output matrix structure
  58  * @return              The function returns either
  59  * <code>ARM_MATH_SIZE_MISMATCH</code> or <code>ARM_MATH_SUCCESS</code> based on the outcome of size checking.
  60  *
  61  * @details
  62  * <b>Scaling and Overflow Behavior:</b>
  63  * \par
  64  * The input data <code>*pSrc</code> and <code>scaleFract</code> are in 1.15 format.
  65  * These are multiplied to yield a 2.30 intermediate result and this is shifted with saturation to 1.15 format.
  66  */
  67
  68 arm_status arm_mat_scale_q15(
  69   const arm_matrix_instance_q15 * pSrc,
  70   q15_t scaleFract,
  71   int32_t shift,
  72   arm_matrix_instance_q15 * pDst)
  73 {
  74   q15_t *pIn = pSrc->pData;                      /* input data matrix pointer */
  75   q15_t *pOut = pDst->pData;                     /* output data matrix pointer */
  76   uint32_t numSamples;                           /* total number of elements in the matrix */
  77   int32_t totShift = 15 - shift;                 /* total shift to apply after scaling */
  78   uint32_t blkCnt;                               /* loop counters */
  79   arm_status status;                             /* status of matrix scaling     */
  80
  81 #ifndef ARM_MATH_CM0_FAMILY
  82
  83   q15_t in1, in2, in3, in4;
  84   q31_t out1, out2, out3, out4;
  85   q31_t inA1, inA2;
  86
  87 #endif //     #ifndef ARM_MATH_CM0_FAMILY
  88
  89 #ifdef ARM_MATH_MATRIX_CHECK
  90   /* Check for matrix mismatch */
  91   if((pSrc->numRows != pDst->numRows) || (pSrc->numCols != pDst->numCols))
  92   {
  93     /* Set status as ARM_MATH_SIZE_MISMATCH */
  94     status = ARM_MATH_SIZE_MISMATCH;
  95   }
  96   else
  97 #endif //    #ifdef ARM_MATH_MATRIX_CHECK
  98   {
  99     /* Total number of samples in the input matrix */
 100     numSamples = (uint32_t) pSrc->numRows * pSrc->numCols;
 101
 102 #ifndef ARM_MATH_CM0_FAMILY
 103
 104     /* Run the below code for Cortex-M4 and Cortex-M3 */
 105     /* Loop Unrolling */
 106     blkCnt = numSamples >> 2;
 107
 108     /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.
 109      ** a second loop below computes the remaining 1 to 3 samples. */
 110     while(blkCnt > 0u)
 111     {
 112       /* C(m,n) = A(m,n) * k */
 113       /* Scale, saturate and then store the results in the destination buffer. */
 114       /* Reading 2 inputs from memory */
 115       inA1 = _SIMD32_OFFSET(pIn);
 116       inA2 = _SIMD32_OFFSET(pIn + 2);
 117
 118       /* C = A * scale */
 119       /* Scale the inputs and then store the 2 results in the destination buffer
 120        * in single cycle by packing the outputs */
 121       out1 = (q31_t) ((q15_t) (inA1 >> 16) * scaleFract);
 122       out2 = (q31_t) ((q15_t) inA1 * scaleFract);
 123       out3 = (q31_t) ((q15_t) (inA2 >> 16) * scaleFract);
 124       out4 = (q31_t) ((q15_t) inA2 * scaleFract);
 125
 126       out1 = out1 >> totShift;
 127       inA1 = _SIMD32_OFFSET(pIn + 4);
 128       out2 = out2 >> totShift;
 129       inA2 = _SIMD32_OFFSET(pIn + 6);
 130       out3 = out3 >> totShift;
 131       out4 = out4 >> totShift;
 132
 133       in1 = (q15_t) (__SSAT(out1, 16));
 134       in2 = (q15_t) (__SSAT(out2, 16));
 135       in3 = (q15_t) (__SSAT(out3, 16));
 136       in4 = (q15_t) (__SSAT(out4, 16));
 137
 138       _SIMD32_OFFSET(pOut) = __PKHBT(in2, in1, 16);
 139       _SIMD32_OFFSET(pOut + 2) = __PKHBT(in4, in3, 16);
 140
 141       /* update pointers to process next sampels */
 142       pIn += 4u;
 143       pOut += 4u;
 144
 145
 146       /* Decrement the numSamples loop counter */
 147       blkCnt--;
 148     }
 149
 150     /* If the numSamples is not a multiple of 4, compute any remaining output samples here.
 151      ** No loop unrolling is used. */
 152     blkCnt = numSamples % 0x4u;
 153
 154 #else
 155
 156     /* Run the below code for Cortex-M0 */
 157
 158     /* Initialize blkCnt with number of samples */
 159     blkCnt = numSamples;
 160
 161 #endif /* #ifndef ARM_MATH_CM0_FAMILY */
 162
 163     while(blkCnt > 0u)
 164     {
 165       /* C(m,n) = A(m,n) * k */
 166       /* Scale, saturate and then store the results in the destination buffer. */
 167       *pOut++ =
 168         (q15_t) (__SSAT(((q31_t) (*pIn++) * scaleFract) >> totShift, 16));
 169
 170       /* Decrement the numSamples loop counter */
 171       blkCnt--;
 172     }
 173     /* Set status as ARM_MATH_SUCCESS */
 174     status = ARM_MATH_SUCCESS;
 175   }
 176
 177   /* Return to application */
 178   return (status);
 179 }
 180
 181 /**
 182  * @} end of MatrixScale group
 183  */