Re: [Qemu-devel] [PATCH] target-arm: Minimal implementation of performance counters

[Peter Maydell]

On 16 May 2011 17:10, Paul Brook <address@hidden> wrote:
>> > I just spoke with Paul on IRC about this. In summary:
>> >  * for a helper to cause an exception then it has (a) to make sure CPU
>> >
>> > state (pc, condflags) is sync'd before the call to the helper and (b)
>> > the helper has to be in a file with access to global env, because it
>> > needs to call cpu_loop_exit()
>>
>> I don't think (a) is true. It is possible to use the same way as for
>> load/store operations, that is call cpu_restore_state() before calling
>> cpu_loop_exit().
>
> To call cpu_restore_state you need to know searched_pc.  To find that you need
> to unwind the host stack all the way back to translated code.

You can do this by calling GETPC() from the top level helper function
though, right? [OK, we'd need to move the definition out of dyngen-exec.h.]

-- PMM