Texas Instruments TMS320C64X manual DSPdotprod, Vector Dot Product

DSP_dotprod

DSP_dotprod	Vector Dot Product
Function		int DSP_dotprod(const short * restrict x, const short * restrict y, int nx)
Arguments		x[nx]	First vector array. Must be double-word aligned.
		y[nx]	Second vector array. Must be double word-aligned.
		nx	Number of elements of vector. Must be multiple of 4.
		return int	Dot product of x and y.
Description		This routine takes two vectors and calculates their dot product. The inputs are
		16-bit short data and the output is a 32-bit number.
Algorithm		This is the C equivalent of the assembly code without restrictions. Note that
		the assembly code is hand optimized and restrictions may apply.

int DSP_dotprod(short x[ ],short y[ ], int nx)

{

int sum; int i; sum = 0;

for(i=0; i<nx; i++){ sum += (x[i] * y[i]);

}

return (sum);

}

Special Requirements

-The input length must be a multiple of 4.

-The input data x[ ] and y[ ] are stored on double-word aligned boundaries.

-To avoid bank conflicts, the input arrays x[ ] and y[ ] must be offset by 4 half-words (8 bytes).

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