Re: [RFC PATCH 0/5] RISC-V: Add dynamic TSO support

From: Andrea Parri
Date: Thu Feb 08 2024 - 06:11:50 EST

On Fri, Nov 24, 2023 at 12:04:09PM +0100, Jonas Oberhauser wrote:
> Unfortunately, at least last time I checked RISC-V still hadn't gotten such
> instructions.
> What they have is the *semantics* of the instructions, but no actual opcodes
> to encode them.
> I argued for them in the RISC-V memory group, but it was considered to be
> outside the scope of that group.

(Sorry for the late, late reply; just recalled this thread...)

That's right. AFAICT, the discussion about the native load-acquire
and store-release instructions was revived somewhere last year within
the RVI community, culminating in the so called Zalasr-proposal [1];
Brendan, Hans and Andrew (+ Cc) might be able to provide more up-to-
date information about the status/plans for that proposal.

(Remark that RISC-V did introduce LR/SCs and AMOs instructions with
acquire/release semantics separately, cf. the so called A-extension.)