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()); ---------------- MaskRay wrote: > broadwaylamb wrote: > > 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? > OK, but I am still confused by the logic and the comment. Does the code just > want to compute the start time in system_clock? Exactly, yes. 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