CMSIS DSP Software Library: arm_mat_scale_q15.c Source File

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# arm_mat_scale_q15.c

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    00001 /* ----------------------------------------------------------------------
    00002 * Copyright (C) 2010 ARM Limited. All rights reserved.
    00003 *
    00004 * $Date:        15. July 2011
    00005 * $Revision:    V1.0.10
    00006 *
    00007 * Project:      CMSIS DSP Library
    00008 * Title:        arm_mat_scale_q15.c
    00009 *
    00010 * Description:  Multiplies a Q15 matrix by a scalar.
    00011 *
    00012 * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
    00013 *
    00014 * Version 1.0.10 2011/7/15
    00015 *    Big Endian support added and Merged M0 and M3/M4 Source code.
    00016 *
    00017 * Version 1.0.3 2010/11/29
    00018 *    Re-organized the CMSIS folders and updated documentation.
    00019 *
    00020 * Version 1.0.2 2010/11/11
    00021 *    Documentation updated.
    00022 *
    00023 * Version 1.0.1 2010/10/05
    00024 *    Production release and review comments incorporated.
    00025 *
    00026 * Version 1.0.0 2010/09/20
    00027 *    Production release and review comments incorporated.
    00028 *
    00029 * Version 0.0.5  2010/04/26
    00030 *    incorporated review comments and updated with latest CMSIS layer
    00031 *
    00032 * Version 0.0.3  2010/03/10
    00033 *    Initial version
    00034 * -------------------------------------------------------------------- */
    00035
    00036 #include "arm_math.h"
    00037
    00063 arm_status arm_mat_scale_q15(
    00064   const arm_matrix_instance_q15 * pSrc,
    00065   q15_t scaleFract,
    00066   int32_t shift,
    00067   arm_matrix_instance_q15 * pDst)
    00068 {
    00069   q15_t *pIn = pSrc->pData;                      /* input data matrix pointer */
    00070   q15_t *pOut = pDst->pData;                     /* output data matrix pointer */
    00071   uint32_t numSamples;                           /* total number of elements in the matrix */
    00072   int32_t totShift = 15 - shift;                 /* total shift to apply after scaling */
    00073   uint32_t blkCnt;                               /* loop counters */
    00074   arm_status status;                             /* status of matrix scaling     */
    00075
    00076 #ifdef ARM_MATH_MATRIX_CHECK
    00077
    00078
    00079   /* Check for matrix mismatch */
    00080   if((pSrc->numRows != pDst->numRows) || (pSrc->numCols != pDst->numCols))
    00081   {
    00082     /* Set status as ARM_MATH_SIZE_MISMATCH */
    00083     status = ARM_MATH_SIZE_MISMATCH;
    00084   }
    00085   else
    00086 #endif /*    #ifdef ARM_MATH_MATRIX_CHECK    */
    00087
    00088   {
    00089     /* Total number of samples in the input matrix */
    00090     numSamples = (uint32_t) pSrc->numRows * pSrc->numCols;
    00091
    00092 #ifndef ARM_MATH_CM0
    00093
    00094     /* Run the below code for Cortex-M4 and Cortex-M3 */
    00095     /* Loop Unrolling */
    00096     blkCnt = numSamples >> 2;
    00097
    00098     /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.
    00099      ** a second loop below computes the remaining 1 to 3 samples. */
    00100     while(blkCnt > 0u)
    00101     {
    00102       /* C(m,n) = A(m,n) * k */
    00103       /* Scale, saturate and then store the results in the destination buffer. */
    00104       *pOut++ =
    00105         (q15_t) (__SSAT(((q31_t) (*pIn++) * scaleFract) >> totShift, 16));
    00106       *pOut++ =
    00107         (q15_t) (__SSAT(((q31_t) (*pIn++) * scaleFract) >> totShift, 16));
    00108       *pOut++ =
    00109         (q15_t) (__SSAT(((q31_t) (*pIn++) * scaleFract) >> totShift, 16));
    00110       *pOut++ =
    00111         (q15_t) (__SSAT(((q31_t) (*pIn++) * scaleFract) >> totShift, 16));
    00112
    00113       /* Decrement the numSamples loop counter */
    00114       blkCnt--;
    00115     }
    00116
    00117     /* If the numSamples is not a multiple of 4, compute any remaining output samples here.
    00118      ** No loop unrolling is used. */
    00119     blkCnt = numSamples % 0x4u;
    00120
    00121 #else
    00122
    00123     /* Run the below code for Cortex-M0 */
    00124
    00125     /* Initialize blkCnt with number of samples */
    00126     blkCnt = numSamples;
    00127
    00128 #endif /* #ifndef ARM_MATH_CM0 */
    00129
    00130     while(blkCnt > 0u)
    00131     {
    00132       /* C(m,n) = A(m,n) * k */
    00133       /* Scale, saturate and then store the results in the destination buffer. */
    00134       *pOut++ =
    00135         (q15_t) (__SSAT(((q31_t) (*pIn++) * scaleFract) >> totShift, 16));
    00136
    00137       /* Decrement the numSamples loop counter */
    00138       blkCnt--;
    00139     }
    00140     /* Set status as ARM_MATH_SUCCESS */
    00141     status = ARM_MATH_SUCCESS;
    00142   }
    00143
    00144   /* Return to application */
    00145   return (status);
    00146 }
    00147

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