Texas Instruments TMS320C67 DSP Series Programmer's Reference Manual page 45

DSPF_sp_fftSPxSP
4-20
w = ptr_w + tw_offset;
for (i = 0; i < N; i += 4)
{
co1 = w[j];
si1 = w[j+1];
co2 = w[j+2];
si2 = w[j+3];
co3 = w[j+4];
si3 = w[j+5];
x_0 = x[0];
x_1 = x[1];
x_h2 = x[h2];
x_h2p1 = x[h2+1];
x_l1 = x[l1];
x_l1p1 = x[l1+1];
x_l2 = x[l2];
x_l2p1 = x[l2+1];
xh0 = x_0
xh1 = x_1
xl0 = x_0
xl1 = x_1
xh20 = x_h2
xh21 = x_h2p1 + x_l2p1;
xl20 = x_h2
xl21 = x_h2p1 - x_l2p1;
ptr_x0 = x;
ptr_x0[0] = xh0 + xh20;
ptr_x0[1] = xh1 + xh21;
ptr_x2 = ptr_x0;
x += 2;
j += 6;
predj = (j - fft_jmp);
if (!predj) x += fft_jmp;
if (!predj) j = 0;
xt0 = xh0 - xh20;
yt0 = xh1 - xh21;
+ x_l1;
+ x_l1p1;
- x_l1;
- x_l1p1;
+ x_l2;
- x_l2;