dsp_vecsumsq.h64

dm642函数库

;* ======================================================================== *;
;*  TEXAS INSTRUMENTS, INC.                                                 *;
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;*  DSPLIB  DSP Signal Processing Library                                   *;
;*                                                                          *;
;*      Release:        Revision 1.04b                                      *;
;*      CVS Revision:   1.8     Sun Sep 29 03:32:30 2002 (UTC)              *;
;*      Snapshot date:  23-Oct-2003                                         *;
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;*  This library contains proprietary intellectual property of Texas        *;
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;*  This software is licensed for use with Texas Instruments TMS320         *;
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;*  the software.  You may review this license by consulting the file       *;
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;* ------------------------------------------------------------------------ *;
;*          Copyright (C) 2003 Texas Instruments, Incorporated.             *;
;*                          All Rights Reserved.                            *;
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;* ======================================================================== *;
;*  Assembler compatibility shim for assembling 4.30 and later code on      *;
;*  tools prior to 4.30.                                                    *;
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;*  End of assembler compatibility shim.                                    *;
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* ========================================================================= *
*                                                                           *
*   TEXAS INSTRUMENTS, INC.                                                 *
*                                                                           *
*   NAME                                                                    *
*       DSP_vecsumsq                                                        *
*                                                                           *
*   REVISION DATE                                                           *
*       29-Mar-2002                                                         *
*                                                                           *
*   USAGE                                                                   *
*       This routine is C callable, and has the following C prototype:      *
*                                                                           *
*           int DSP_vecsumsq                                                *
*           (                                                               *
*               const short *x,    /* Pointer to vector  */                 *
*               int          nx    /* Length of vector.  */                 *
*           );                                                              *
*                                                                           *
*       This routine returns the sum of squares as its return value.        *
*                                                                           *
*   DESCRIPTION                                                             *
*       The "DSP_vecsumsq" function returns the sum of squares of the       *
*       elements contained in vector "x".                                   *
*                                                                           *
*   C CODE                                                                  *
*       The following C code is a general implementation without            *
*       restrictions.  This implementation may have restrictions, as        *
*       noted under "ASSUMPTIONS" below.                                    *
*                                                                           *
*           int DSP_vecsumsq                                                *
*           (                                                               *
*               const short *x,    /* Pointer to vector  */                 *
*               int          nx    /* Length of vector.  */                 *
*           )                                                               *
*           {                                                               *
*               int i, sum = 0;                                             *
*                                                                           *
*               for (i = 0; i < nx; i++)                                    *
*                   sum += x[i] * x[i];                                     *
*                                                                           *
*               return sum;                                                 *
*           }                                                               *
*                                                                           *
*   TECHNIQUES                                                              *
*       The code is unrolled 4 times to enable full memory and multiplier   *
*       bandwidth to be utilized.                                           *
*                                                                           *
*   ASSUMPTIONS                                                             *
*       The input length is a multiple of 4 and at >= 12.                   *
*                                                                           *
*   NOTES                                                                   *
*       This code is ENDIAN NEUTRAL                                         *
*                                                                           *
*       This function is interrupt tolerant, but not interruptible.         *
*       It locks out interrupts for its entire duration.                    *
*                                                                           *
*   MEMORY NOTE                                                             *
*       This function is ENDIAN NEUTRAL.                                    *
*       No bank conflicts occur under any conditions.                       *
*                                                                           *
*   CYCLES                                                                  *
*       cycles = nx/2 + 11.                                                 *
*                                                                           *
*   CODESIZE                                                                *
*       148 bytes                                                           *
*                                                                           *
* ------------------------------------------------------------------------- *
*             Copyright (c) 2003 Texas Instruments, Incorporated.           *
*                            All Rights Reserved.                           *
* ========================================================================= *

        .global _DSP_vecsumsq

* ========================================================================= *
*   End of file:  dsp_vecsumsq.h64                                          *
* ------------------------------------------------------------------------- *
*             Copyright (c) 2003 Texas Instruments, Incorporated.           *
*                            All Rights Reserved.                           *
* ========================================================================= *