Re: [Qemu-arm] [PATCH 06/67] target/arm: Introduce pc_read

[Richard Henderson]

On 8/6/19 8:21 AM, Peter Maydell wrote:
> On Tue, 6 Aug 2019 at 16:04, Richard Henderson
> <address@hidden> wrote:
>>
>> On 8/6/19 3:00 AM, Peter Maydell wrote:
>>> Renaming pc_next would be a cross-target change, so let's put that
>>> on the shelf for the moment. Maybe just put a TODO comment to the
>>> effect that we could consider renaming in future ?
>>
>> I wasn't suggesting renaming the cross-target variable.
>>
>> I was suggesting shuffling around the current names, and using "pc_next" for
>> what it sounds like -- the pc of the next insn.
> 
> Oh, I see, so incrementing base->pc_next after we load
> the insn? Yeah, that would work too. Though it seems a bit
> odd to me to have the target-specific code modifying
> a field in the base struct -- that seems like it ought to
> be purely for the generic TCG code to use.

Part of the contract with translator.c is that base.pc_next is updated.  See
arm_post_translate_insn.

The difference would be to update early, immediately after reading the insn
word, before decode, instead of delaying the update until the end after decode.


r~