omxsp_dotprod_s16.c

来自「The OpenMAX DL (Development Layer) APIs 」· C语言 代码 · 共 82 行

/**
 * 
 * File Name:  omxSP_DotProd_S16.c
 * OpenMAX DL: v1.0.2
 * Revision:   10586
 * Date:       Wednesday, March 5, 2008
 * 
 * (c) Copyright 2007-2008 ARM Limited. All Rights Reserved.
 * 
 * 
 *
 * Description:
 * This file contains module for Dot Product of two vectors
 *
 */

#include "omxtypes.h"
#include "armOMX.h"
#include "omxSP.h"

/**
 * Function:  omxSP_DotProd_S16   (2.2.2.1.1)
 *
 * Description:
 * Calculates the dot product of the two input vectors.  This function does 
 * not perform scaling. The internal accumulator width must be at least 32 
 * bits.  If any of the partially accumulated values exceeds the range of a 
 * signed 32-bit integer then the result is undefined. 
 *
 * Input Arguments:
 *   
 *   pSrc1 - pointer to the first input vector; must be aligned on an 8-byte 
 *            boundary. 
 *   pSrc2 - pointer to the second input vector; must be aligned on an 8-byte 
 *            boundary. 
 *   len - length of the vectors in pSrc1 and pSrc2 
 *
 * Output Arguments:
 *
 * Return Value:
 *    
 *    The dot product result  Note: this function returns the actual result 
 *              rather than the standard OMXError. 
 *
 */


OMX_S32 omxSP_DotProd_S16(
                            const OMX_S16 *pSrc1,
                            const OMX_S16 *pSrc2,
                            OMX_INT        len
                            )
{
    OMX_S32 DotProd;
    OMX_S32 Var1,Var2;
    
    /* Return if value 'len' is not valid */
    
    if(len <= 0)
    {
       return (OMX_S32)0;
    }
    
    /* Compute the DotProduct */
    
    DotProd = 0;
    
    do
    {
        Var1 = *pSrc1++;
        Var2 = *pSrc2++;
        
        DotProd += (OMX_S32)(Var1*Var2);
                
        len--;
        
    }while(len != 0);

    return DotProd;
} 
/* End of File */