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Subject: Re: [Qemu-devel] [PATCH] target-*: Get rid of "PC advancement" trick
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To: Sergey Fedorov <serge.fdrv@gmail.com>, qemu-devel@nongnu.org
Cc: Peter Maydell <peter.maydell@linaro.org>, Eduardo Habkost <ehabkost@redhat.com>, Anthony Green <green@moxielogic.com>, Alexander Graf <agraf@suse.de>, Max Filippov <jcmvbkbc@gmail.com>, Michael Walle <michael@walle.cc>, qemu-arm@nongnu.org, qemu-ppc@nongnu.org, "Edgar E. Iglesias" <edgar.iglesias@gmail.com>, Paolo Bonzini <pbonzini@redhat.com>, Guan Xuetao <gxt@mprc.pku.edu.cn>, Leon Alrae <leon.alrae@imgtec.com>, Aurelien Jarno <aurelien@aurel32.net>, Jia Liu <proljc@gmail.com>

On 12/15/2015 01:02 PM, Sergey Fedorov wrote:
>> For that, I think it might be interesting to arrange for non-empty TBs to
>> exit prior to recognizing a breakpoint.  So that a breakpoint TB is always
>> just the one operation.  Except for the fact that "generate an exception" has
>> traditionally been a target-specific helper, we could almost make the entire
>> breakpoint generation be done in common code.
>>
>> I'd think something like a generic "must we end the TB now" predicate would
>> be the proper hook.  It would contain all of the usual stuff: tcg_op_buf_full
>> and checks for singlestep, but then add "is there a breakpoint at the next pc".
>
> This could be a next step :)

Or perhaps a first step, since the patch you posted doesn't seem to me to be an 
improvement at all, merely a rearrangement of code.


r~