Re: [Qemu-devel] [RFC] Streamlining endian handling in TCG

[Richard Henderson]

On 08/28/2013 09:38 AM, Peter Maydell wrote:
>> (B) Add an additional bit to the "opc" to indicate which endianness is 
>> desired.
>>  E.g. 0 = LE, 8 = BE.  Expose the opc interface to the translators.  At which
>> point generating a load becomes more like
>>
>>     tcg_gen_qemu_ld_tl(dest, addr, size | sign | dc->big_endian);
>>
>> and the current endianness of the guest becomes a bit on the TB, to be copied
>> into the DisasContext at the beginning of translation.
> 
> I guess we deal with ARMv5-style BE32 by having the target
> emit an explicit XOR TCG op?

Yes.  I see no other way to implement that.

> Do we need to overhaul the C interface to the
> memory system too? (ie ldl_p and friends).

I don't think so, since we already have ldl_{le,be}_p.


r~