[Libre-soc-dev] MP3 DCT36

[Luke Kenneth Casson Leighton]

for (i = 17; i >= 3; i -= 2)
        in[i] += in[i-2];

drat.  *another* candidate for REMAP, with "inverse" (countdown) mode,
XDIM set to 17, YDIM set to 2, then the VL forloop it will generate 17
15 13 11 ... 3

i would suggest using mask 0b0101010101 with mapreduce to overlap the
sums, but there's no reverse gear (count backwards)... unless we add
one? there is potentially one bit spare.  we lose the CR Mode in the
process.

l.