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

[Alex Bennée]

Richard Henderson <address@hidden> writes:

> 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.

I'm mainly thinking about keeping in line with the layout of the rest of
the code. I would home the compiler would generate the same either way!

--
Alex Bennée