Re: [PATCH] tcg: Increase width of temp_subindex

[Michael Tokarev]

13.02.2024 08:44, Michael Tokarev wrote:
> 13.02.2024 05:21, Richard Henderson:
> > We need values 0-3 for TCG_TYPE_I128 on 32-bit hosts.
> >
> > Cc: qemu-stable@nongnu.org
> > Fixes: 43eef72f4109 ("tcg: Add temp allocation for TCGv_i128")
> > Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2159
> > Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> > ---
> >
> > I feel certain that I made this change back when I introduced TCGv_i128.
> > I imagine that something went wrong with a rebase and it got lost.
> > Worse, we don't use temp_subindex often, and we usually handle i128
> > this value correctly.  It took a quirk of register allocation ordering
> > to make an invalid value in temp_subindex lead to a crash.
>
> Somehow it feels deja vue too, maybe we increased some other width like
> this already, in stable series too, but I can't find it now.
>
> "This" in "this value" should be omitted. With this fixed,

This is that "ENOCOFFEE" time once again ;) - I haven't noticed this
is a comment *after* the patch description.

> Reviewed-by: Michael Tokarev <mjt@tls.msk.ru>

Tested-by: Michael Tokarev <mjt@tls.msk.ru>

I run several different guests here which did show the same crash, -
none of them crashes after this patch.

/mjt