Re: [Qemu-devel] [RFC v3 PATCH 03/14] tcg/aarch64: Add support for fence

[Richard Henderson]

On 06/23/2016 09:18 AM, Alex Bennée wrote:
> > > +    /* System instructions.  */
> > > +    DMB_ISH         = 0xd50338bf,
> As ISH is part of the CRm encoding I wonder if this should be split into
> the main DMB encoding (0xd50330bf) and a separate set of CRm defines.
>
> In fact the documentation of the struct above implies you should
> probably have:
>
>        I6260_DMB       = 0xd50330bf,
>
> And then:
>
> static void tcg_out_insn_6260(TCGContext *s, AArch64Insn insn, int crm);
> {
>     tcg_out32(s, insn | (crm & 0xf) << 8);
> }

I don't see any benefit to doing this over or-ing in the pre-shifted values.


r~