broadwaylamb marked an inline comment as done.
broadwaylamb added inline comments.
================
Comment at: llvm/lib/Support/TimeProfiler.cpp:266
+ const auto BeginningOfTimeUs = SystemTime - ProcessLocalTime;
+ J.attribute("beginningOfTime",
+ BeginningOfTimeUs.time_since_epoch().count());
----------------
broadwaylamb wrote:
> MaskRay wrote:
> > What is the logic here?
> >
> > Two events in the same process may have different `beginningOfTime`. Is
> > that intended?
> >
> > Noe that `system_clock::now()` and `steady_clock::now()` are not measured
> > at the same time.
> >Two events in the same process may have different beginningOfTime. Is that
> >intended?
>
> How would that be possible? We only compute `beginningOfTime` when writing
> the data of the time profiler to a JSON file. AFAICT it happens only once.
> So, this code is only called once.
>
> >Noe that system_clock::now() and steady_clock::now() are not measured at the
> >same time.
> I understand. But the difference should be very small (certainly less than a
> microsecond), since there are only a few arithmetic operations in between.
Although we could set the beginning of time in `TimeProfiler`'s constructor and
assign it to a field. That would be a lot simpler, I guess. What do you think?
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D78030/new/
https://reviews.llvm.org/D78030
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
