I was thinking more about this. We currently appear to have, one way or the
other, an inconsistency when it comes to offsets: ll_prof outputs offsets
in hex, the d8 pretty printers output in dec.

At a high level, what do we believe is the right thing to do here? Do we
want them in decimal everywhere (case in which I'll modify ll_prof or
disasm.py) or do we want them in hex everywhere?

While the latter may be a more unpleasant path, I feel it is the better
answer: if we start using other tools for analysis - just like ll_prof
today reuses objdump - I think hex will prove to be the common format for
offsets, rather than dec.

If we agree on that, do we have a comprehensive list of places we print
offsets? That would make the change straightforward.

If no such list exists, I can see 2 options for making progress with
calculated risk:

1) introduce a flag, print hex by default. If someone discovers we missed a
spot, they may disable the flag in their runs (to unblock their work), and
either fix or file a bug. Eventually we remove the flag altogether.

2) no flag, cold turkey option. We do best effort upfront, and treat
subsequently discovered incorrectly formatted offsets as bugs, which we
then fix.

I prefer option 2, because option 1 will likely complicate the code for the
interim until we're satisfied the change is complete. Option 2 seems like
would get us where we want fastest.

Thoughts?

On Tue, Jun 16, 2015 at 6:36 AM Mircea Trofin <[email protected]> wrote:

>
>
> The goal was to make correlating with "perf" output easy, so offsets are
> sufficient in that case. Would a flag to enable only offsets in hex address
> your concern? Something like --decomp-offsets-hex.
>
> If we feel we wanted a master switch instead (all numbers to hex), we
> could call the flag something like "--use-hex", and gradually (over many
> CLs) change other traces. But I don't know if we have scenarios asking for
> that just yet.
>
>
> Thoughts?
>
> Thanks!
> On Tue, Jun 16, 2015 at 03:36 <[email protected]> wrote:
>
>> A revert of this CL (patchset #2 id:20001) has been created in
>> https://codereview.chromium.org/1188093002/ by [email protected].
>>
>> The reason for reverting is: Code printout has become unreadable. Offsets
>> are
>> printed in decimal numbers everywhere else. This is inconsistent with the
>> rest
>> of the code-base. Some examples are tables for deoptimization data,
>> safepoints
>> and exception handlers. I would be fine with this change if _all_ tracing
>> would
>> be adapted. But there are _many_ places to touch..
>>
>> https://codereview.chromium.org/1177123002/
>>
>

-- 
-- 
v8-dev mailing list
[email protected]
http://groups.google.com/group/v8-dev
--- 
You received this message because you are subscribed to the Google Groups 
"v8-dev" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to [email protected].
For more options, visit https://groups.google.com/d/optout.

Reply via email to