Re: [PATCH v4 00/27] tcg/s390x: misc patches

[Ilya Leoshkevich]

On Thu, Dec 08, 2022 at 08:05:03PM -0600, Richard Henderson wrote:
> Based-on: 20221202053958.223890-1-richard.henderson@linaro.org
> ("[PATCH for-8.0 v3 00/34] tcg misc patches")
> 
> Changes from v3:
>   * Require z196 as minimum cpu -- 6 new patches removing checks.
>   * Tighten constraints on AND, OR, XOR, CMP, trying get the register
>     allocator to hoist things that can't be done in a single insn.
>   * Avoid the constant pool for movi.
> 
> I believe that I have addressed all of the discussion in v3,
> except perhaps for goto_tb concurrent modifications to jumps.
> I'm still not quite sure what to do about that.

I asked around, and apparently some other JITs (e.g. Java and .NET) are
doing atomic branch offset patching (provided the offset is aligned,
which QEMU does already ensure) on s390x for a long time now, and
without known issues. So I'm okay with keeping this code as is.

<...>

Best regards,
Ilya