[PATCH] RISC-V : Support bitmanip-0.93 ZBA/ZBB/ZBC instructions

[Andrew Waterman]

I don't believe the spec is in error.  zext.w is not in Zbb; it is a
pseudoinstruction for add.uw in Zba.  This is consistent in one sense
(Zba contains most of the instructions that help with uint32 on RV64)
and inconsistent in another sense (Zbb contains most of the extension
instructions), but it is what it is.


On Thu, Feb 25, 2021 at 12:21 PM Jim Wilson <jimw@sifive.com> wrote:
>
> On Thu, Feb 25, 2021 at 12:44 AM Kuan-Lin Chen <kuanlinchentw@gmail.com>
> wrote:
>
> > Btw, zext.w don't list on "Table 2.1: Zb* extensions instruction listings"
> > of  bitmanip-draft.pdf (
> > https://github.com/riscv/riscv-bitmanip/blob/master/bitmanip-draft.pdf).
> > Maybe we can add zext.w on the table to avoid other people missing it.
> >
>
> bitmanip-draft.pdf is probably out of date, but I checked a freshly built
> one from source and it is still missing.  So I filed an issue against the
> riscv-bitmanip project to point out the problem.
>
> Jim