Texas Instruments TMS320C64X Programmer's Reference Manual page 143

}
else
{
y1 = y0 + (int) (npoints >> 1);
y3 = y2 + (int) (npoints >> 1);
l1 = norm + 2;
j0 = 4;
n0 = npoints >> 2;
}
/*−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−*/
/* The following code reads data indentically for either a radix 4
/* or a radix 2 style decomposition. It writes out at different
/* locations though. It checks if either half the points, or a
/* quarter of the complex points have been exhausted to jump to
/* pervent double reversal.
/*−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−*/
j = 0;
for (i = 0; i < npoints; i += 8)
{
/*−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−*/
/* Digit reverse the index starting from 0. The increment to "j"
/* is either by 4, or 8.
/*−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−*/
DIG_REV(j, l1, h2);
/*−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−*/
/* Read in the input data, from the first eight locations. These
/* are transformed either as a radix4 or as a radix 2.
/*−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−*/
x_0 = x0[0];
x_2 = x0[2];
x_4 = x0[4];
x_6 = x0[6];
x0 += 8;
xh0_0 = x_0 + x_4;
xl0_0 = x_0 − x_4;
xh0_1 = x_2 + x_6;
x_1 = x0[1];
x_3 = x0[3];
x_5 = x0[5];
x_7 = x0[7];
xh1_0 = x_1 + x_5;
xl1_0 = x_1 − x_5;
xh1_1 = x_3 + x_7;
DSP_fft16x16t
C64x+ DSPLIB Reference
*/
*/
*/
*/
*/
*/
*/
*/
*/
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