tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/MatrixFunctions/arm_mat_mult_q31.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_mult_q31.c
   9 *
  10 * Description:   Q31 matrix multiplication.
  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 MatrixMult
  49  * @{
  50  */
  51
  52 /**
  53  * @brief Q31 matrix multiplication
  54  * @param[in]       *pSrcA points to the first input matrix structure
  55  * @param[in]       *pSrcB points to the second input matrix structure
  56  * @param[out]      *pDst points to output matrix structure
  57  * @return              The function returns either
  58  * <code>ARM_MATH_SIZE_MISMATCH</code> or <code>ARM_MATH_SUCCESS</code> based on the outcome of size checking.
  59  *
  60  * @details
  61  * <b>Scaling and Overflow Behavior:</b>
  62  *
  63  * \par
  64  * The function is implemented using an internal 64-bit accumulator.
  65  * The accumulator has a 2.62 format and maintains full precision of the intermediate
  66  * multiplication results but provides only a single guard bit. There is no saturation
  67  * on intermediate additions. Thus, if the accumulator overflows it wraps around and
  68  * distorts the result. The input signals should be scaled down to avoid intermediate
  69  * overflows. The input is thus scaled down by log2(numColsA) bits
  70  * to avoid overflows, as a total of numColsA additions are performed internally.
  71  * The 2.62 accumulator is right shifted by 31 bits and saturated to 1.31 format to yield the final result.
  72  *
  73  * \par
  74  * See <code>arm_mat_mult_fast_q31()</code> for a faster but less precise implementation of this function for Cortex-M3 and Cortex-M4.
  75  *
  76  */
  77
  78 arm_status arm_mat_mult_q31(
  79   const arm_matrix_instance_q31 * pSrcA,
  80   const arm_matrix_instance_q31 * pSrcB,
  81   arm_matrix_instance_q31 * pDst)
  82 {
  83   q31_t *pIn1 = pSrcA->pData;                    /* input data matrix pointer A */
  84   q31_t *pIn2 = pSrcB->pData;                    /* input data matrix pointer B */
  85   q31_t *pInA = pSrcA->pData;                    /* input data matrix pointer A */
  86   q31_t *pOut = pDst->pData;                     /* output data matrix pointer */
  87   q31_t *px;                                     /* Temporary output data matrix pointer */
  88   q63_t sum;                                     /* Accumulator */
  89   uint16_t numRowsA = pSrcA->numRows;            /* number of rows of input matrix A    */
  90   uint16_t numColsB = pSrcB->numCols;            /* number of columns of input matrix B */
  91   uint16_t numColsA = pSrcA->numCols;            /* number of columns of input matrix A */
  92
  93 #ifndef ARM_MATH_CM0_FAMILY
  94
  95   /* Run the below code for Cortex-M4 and Cortex-M3 */
  96
  97   uint16_t col, i = 0u, j, row = numRowsA, colCnt;      /* loop counters */
  98   arm_status status;                             /* status of matrix multiplication */
  99   q31_t a0, a1, a2, a3, b0, b1, b2, b3;
 100
 101 #ifdef ARM_MATH_MATRIX_CHECK
 102
 103
 104   /* Check for matrix mismatch condition */
 105   if((pSrcA->numCols != pSrcB->numRows) ||
 106      (pSrcA->numRows != pDst->numRows) || (pSrcB->numCols != pDst->numCols))
 107   {
 108     /* Set status as ARM_MATH_SIZE_MISMATCH */
 109     status = ARM_MATH_SIZE_MISMATCH;
 110   }
 111   else
 112 #endif /*    #ifdef ARM_MATH_MATRIX_CHECK    */
 113
 114   {
 115     /* The following loop performs the dot-product of each row in pSrcA with each column in pSrcB */
 116     /* row loop */
 117     do
 118     {
 119       /* Output pointer is set to starting address of the row being processed */
 120       px = pOut + i;
 121
 122       /* For every row wise process, the column loop counter is to be initiated */
 123       col = numColsB;
 124
 125       /* For every row wise process, the pIn2 pointer is set
 126        ** to the starting address of the pSrcB data */
 127       pIn2 = pSrcB->pData;
 128
 129       j = 0u;
 130
 131       /* column loop */
 132       do
 133       {
 134         /* Set the variable sum, that acts as accumulator, to zero */
 135         sum = 0;
 136
 137         /* Initiate the pointer pIn1 to point to the starting address of pInA */
 138         pIn1 = pInA;
 139
 140         /* Apply loop unrolling and compute 4 MACs simultaneously. */
 141         colCnt = numColsA >> 2;
 142
 143
 144         /* matrix multiplication */
 145         while(colCnt > 0u)
 146         {
 147           /* c(m,n) = a(1,1)*b(1,1) + a(1,2) * b(2,1) + .... + a(m,p)*b(p,n) */
 148           /* Perform the multiply-accumulates */
 149           b0 = *pIn2;
 150           pIn2 += numColsB;
 151
 152           a0 = *pIn1++;
 153           a1 = *pIn1++;
 154
 155           b1 = *pIn2;
 156           pIn2 += numColsB;
 157           b2 = *pIn2;
 158           pIn2 += numColsB;
 159
 160           sum += (q63_t) a0 *b0;
 161           sum += (q63_t) a1 *b1;
 162
 163           a2 = *pIn1++;
 164           a3 = *pIn1++;
 165
 166           b3 = *pIn2;
 167           pIn2 += numColsB;
 168
 169           sum += (q63_t) a2 *b2;
 170           sum += (q63_t) a3 *b3;
 171
 172           /* Decrement the loop counter */
 173           colCnt--;
 174         }
 175
 176         /* If the columns of pSrcA is not a multiple of 4, compute any remaining output samples here.
 177          ** No loop unrolling is used. */
 178         colCnt = numColsA % 0x4u;
 179
 180         while(colCnt > 0u)
 181         {
 182           /* c(m,n) = a(1,1)*b(1,1) + a(1,2) * b(2,1) + .... + a(m,p)*b(p,n) */
 183           /* Perform the multiply-accumulates */
 184           sum += (q63_t) * pIn1++ * *pIn2;
 185           pIn2 += numColsB;
 186
 187           /* Decrement the loop counter */
 188           colCnt--;
 189         }
 190
 191         /* Convert the result from 2.62 to 1.31 format and store in destination buffer */
 192         *px++ = (q31_t) (sum >> 31);
 193
 194         /* Update the pointer pIn2 to point to the  starting address of the next column */
 195         j++;
 196         pIn2 = (pSrcB->pData) + j;
 197
 198         /* Decrement the column loop counter */
 199         col--;
 200
 201       } while(col > 0u);
 202
 203 #else
 204
 205   /* Run the below code for Cortex-M0 */
 206
 207   q31_t *pInB = pSrcB->pData;                    /* input data matrix pointer B */
 208   uint16_t col, i = 0u, row = numRowsA, colCnt;  /* loop counters */
 209   arm_status status;                             /* status of matrix multiplication */
 210
 211
 212 #ifdef ARM_MATH_MATRIX_CHECK
 213
 214   /* Check for matrix mismatch condition */
 215   if((pSrcA->numCols != pSrcB->numRows) ||
 216      (pSrcA->numRows != pDst->numRows) || (pSrcB->numCols != pDst->numCols))
 217   {
 218     /* Set status as ARM_MATH_SIZE_MISMATCH */
 219     status = ARM_MATH_SIZE_MISMATCH;
 220   }
 221   else
 222 #endif /*    #ifdef ARM_MATH_MATRIX_CHECK    */
 223
 224   {
 225     /* The following loop performs the dot-product of each row in pSrcA with each column in pSrcB */
 226     /* row loop */
 227     do
 228     {
 229       /* Output pointer is set to starting address of the row being processed */
 230       px = pOut + i;
 231
 232       /* For every row wise process, the column loop counter is to be initiated */
 233       col = numColsB;
 234
 235       /* For every row wise process, the pIn2 pointer is set
 236        ** to the starting address of the pSrcB data */
 237       pIn2 = pSrcB->pData;
 238
 239       /* column loop */
 240       do
 241       {
 242         /* Set the variable sum, that acts as accumulator, to zero */
 243         sum = 0;
 244
 245         /* Initiate the pointer pIn1 to point to the starting address of pInA */
 246         pIn1 = pInA;
 247
 248         /* Matrix A columns number of MAC operations are to be performed */
 249         colCnt = numColsA;
 250
 251         /* matrix multiplication */
 252         while(colCnt > 0u)
 253         {
 254           /* c(m,n) = a(1,1)*b(1,1) + a(1,2) * b(2,1) + .... + a(m,p)*b(p,n) */
 255           /* Perform the multiply-accumulates */
 256           sum += (q63_t) * pIn1++ * *pIn2;
 257           pIn2 += numColsB;
 258
 259           /* Decrement the loop counter */
 260           colCnt--;
 261         }
 262
 263         /* Convert the result from 2.62 to 1.31 format and store in destination buffer */
 264         *px++ = (q31_t) (sum >> 31);
 265
 266         /* Decrement the column loop counter */
 267         col--;
 268
 269         /* Update the pointer pIn2 to point to the  starting address of the next column */
 270         pIn2 = pInB + (numColsB - col);
 271
 272       } while(col > 0u);
 273
 274 #endif
 275
 276       /* Update the pointer pInA to point to the  starting address of the next row */
 277       i = i + numColsB;
 278       pInA = pInA + numColsA;
 279
 280       /* Decrement the row loop counter */
 281       row--;
 282
 283     } while(row > 0u);
 284
 285     /* set status as ARM_MATH_SUCCESS */
 286     status = ARM_MATH_SUCCESS;
 287   }
 288   /* Return to application */
 289   return (status);
 290 }
 291
 292 /**
 293  * @} end of MatrixMult group
 294  */