DSP M-Registers
@DrWatson
Published in
atari
· 8 Nov 2023
... n re-reversing the last k bits of r0 again. Apparently this is *very* useful when doing things like "twiddle factors" with FFTs. Interestingly(?), if we consider a setting where Nn = 1024, using reverse carry repeatedly with the following code: move #Output_buffer,r1 move #0,r0 move #0,m0 ; select reverse-carry move #512,n0 ; our reverse carry "increment" do #100,rc_loop move r0,x:(r1)+ lua (r0)+n0,r0 nop ; wait for pipeline rc_loop: ... produces the following sequence: 0, 512, 256, 768, 128, 640 ... o ...