[libre-riscv-dev] Instruction sorta-prefixes for easier high-register access

[Luke Kenneth Casson Leighton]

On Tue, Jan 22, 2019 at 8:08 AM Jacob Lifshay <programmerjake at gmail.com> wrote:

> Changes to the proposal:
> I changed where elmsz comes from in integer size conversions, using
> OP-IMM/OP-IMM-32 to differentiate between unsigned/signed.
> I split the elmsz mapping into elmszd/elmszw to allow reordering to match
> the unprefixed sizes.

 the thing about elwidth is that there needs to be one for the source
operands and a *separate* one for the destination register

 otherwise, explicit operations are needed which perform
width-conversions.  which is feasible: special over-ride on MV / F.MV.

 also, how is vector-scalar and scalar-vector to be specified?

> I added operations allowing compare into mask for both int and fp (f<fcc>.m
> and cmpm).
> I added reciprocal-sqrt (frsqrt).
> I changed all the type conversions for c.conv to Reserved, the c.mv entries
> were left alone.

 cool, am going over it.