Texas Instruments TMS320C64X manual Sum of Squares, DSPvecsumsq

			DSP_vecsumsq
	Sum of Squares
DSP_vecsumsq
Function		int DSP_vecsumsq (const short *x, int nx)
Arguments		x[nx]	Input vector
		nx	Number of elements in x. Must be multiple of 4 and ≥8.
		return int	Sum of the squares
Description		This routine returns the sum of squares of the elements contained in the vector
		x[ ].
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_vecsumsq(short x[ ], int nx)

{

int i, sum=0;

for(i=0; i<nx; i++)

{

sum += x[i]*x[i];

}

return(sum);

}

Special Requirements nx must be a multiple of 4 and greater than or equal to 32.

Implementation Notes

	- Bank Conflicts: No bank conflicts occur.
	- Interruptibility: The code is interrupt-tolerant but not interruptible.
	- The code is unrolled 4 times to enable full memory and multiplier
	bandwidth to be utilized.
Benchmarks	Cycles	nx/4 + 11
	Codesize	188 bytes

C64x+ DSPLIB Reference 4-71