[Libre-soc-dev] Inverse DCT

[Luke Kenneth Casson Leighton]

i have moved on to prototyping inverse DCT now.

i have a partially completed iterative algorithm with just a bit more
mungeing it will be similar in nature to the DCT version: a
bit-reversed LD followed by outer schedule then an inner one.

there are some weird quirks in iDCT such as dividing element zero by 2
before starting, so it is not entirely an inverse mirror of the DCT
operations.

the top-half-swapping is particularly obtuse and different, currently
dealing with that.

with both sets of operations DCT and iDCT i will be able to merge the
schedules together and finalise the first version of svshape
instruction.

l.