Bit-reverse every byte
b ~0,~1,~2,3,4,5,6,7,8
Turn vector of 8 u64 into 64 u8 (transpose 8x64)
b 6,7,8,0,1,2,3,4,5
Turn vector of 16 u32 into 32 u16 (transpose 16x32)
b 5,6,7,8,0,1,2,3,4
16x16 transpose in each 256-bit part
b 4,5,6,7,0,1,2,3,8
You can dump a full array of 512 indices into the query box (no prefix, comma-separated, spaces are allowed), or 9 indices-of-bits-of-indices (with the "b" prefix). If you use raw indices, the permutation must still correspond to a BPC permutation.
Put the least-significant index first, but the print-back shows the indices most-significant-first. Use source indices in raw mode, but destination indices in b mode. Yes, it's confusing. Sorry.
In b mode, the ~ operator is available to complement a bit. It does not complement the number after it, but the corresponding bit.
Consider this an alpha version for now. Expect bugs. You can open an issue or contact me (eg via email, Mastodon @harold@mastodon.gamedev.place or twitter @HaroldAptroot).