Texas Instruments TMS320C64X - Manual (Page 115)

DSP_minerror
4-87 C64x+ DSPLIB Reference
Minimum Energy Error Search DSP_minerror
Function int minerror (const short * restrict GSP0_TABLE, const short * restrict
errCoefs, int * restrict max_index)
Arguments GSP0_TABLE[9*256] GSP0 terms array. Must be double-word aligned.
errCoefs[9] Array of error coefficients.
max_index Pointer to GSP0_TABLE[max_index] found.
return int Maximum dot product result.
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 minerr
(
const short *restrict GSP0_TABLE,
const short *restrict errCoefs,
int *restrict max_index
)
{
int val, maxVal = −50;
int i, j;
for (i = 0; i < GSP0_NUM; i++)
{
for (val = 0, j = 0; j < GSP0_TERMS; j++)
val += GSP0_TABLE[i*GSP0_TERMS+j] * errCoefs[j];
if (val > maxVal)
{
maxVal = val;
*max_index = i*GSP0_TERMS;
}
}
return (maxVal);
}