Re: [PATCH] target/ppc: Fix SPE unavailable exception triggering

[Matthieu Bucchianeri]

Hello Balaton,

Thank you for your thorough review! See my response below.

> > static inline void gen_evmwsmiaa(DisasContext *ctx) {
> > -    TCGv_i64 acc = tcg_temp_new_i64();
> > -    TCGv_i64 tmp = tcg_temp_new_i64();
> > +    TCGv_i64 acc;
> > +    TCGv_i64 tmp;
> > +
> > +    if (unlikely(!ctx->spe_enabled)) {
> > +        gen_exception(ctx, POWERPC_EXCP_SPEU);
> > +        return;
> > +    }
>
> Isn't this missing here:
>
> acc = tcg_temp_new_i64();
> tmp = tcg_temp_new_i64();
>
> You've removed allocating temps but this hunk does not add it back after the
> exception unlike others in this patch.

I should have probably mentioned somewhere that this patch also
fixes a resource leak in that function. It is not very obvious
when looking at it as a patch, but if you take a look at the
original code, you will see that I removed these allocations on
purpose:

https://github.com/qemu/qemu/blob/d577dbaac7553767232faabb6a3e291aebd348ae/target/ppc/translate/spe-impl.inc.c#L532

> static inline void gen_evmwsmiaa(DisasContext *ctx)
> {
>     TCGv_i64 acc = tcg_temp_new_i64();
>     TCGv_i64 tmp = tcg_temp_new_i64();
>
>     gen_evmwsmi(ctx);           /* rD := rA * rB */
>
>     acc = tcg_temp_new_i64();
>     tmp = tcg_temp_new_i64();

I apologize for not making this any more clear in my description.

Let me know if this looks correct now, with the full context in mind.

Thanks.

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