[Libre-soc-dev] [RFC] SVP64 on branch instructions

[Luke Kenneth Casson Leighton]

https://libre-soc.org/openpower/sv/branches/

i created this page with various modes, i believe only "ALL/SOME" is
needed because by inverting the BO test itself ~ALL and ~SOME are
achieved.

strictly speaking illegal instructions should be raised for mode
combinations that make no sense however given how gate critical thus
is, and how doing so would create Hazard dependencies on SVSTATE,
compromising multi issue execution in the process, i am very reluctant
to do that.

detection of Branch SVPY4 RM Mode is quite straightforward, there is
major op 18 and two minor op 19s, this is not a lot for the early
decode phase.

l.