On Thu, Sep 24, 2015 at 1:58 PM, dmonji <monikadhok...@gmail.com> wrote:
> 1) In v8, ic.cc, i see functions like > *RUNTIME_FUNCTION(Runtime_KeyedLoadIC_Miss)*. > I don't understand how are they invoked. Is there some connection > with * __ TailCallRuntime(Runtime::kKeyedLoadIC_Miss, arg_count, 1);* > from ic-<arch>.cc? > Yes, that's precisely how they're invoked. > 2) what is the difference between *Runtime_KeyedLoadIC_Miss* and > *Runtime_LoadIC_Miss > *? > Essentially, foo.bar is a load and foo[bar] is a keyed load. > 3) Can I profile these runtime functions using some c++ profiler? I want > to see how much time is spent on subset of these runtime functions. > Sure, C++ profilers can profile C++ functions. However, profiling short-running functions is notoriously hard because of the overhead that profiling introduces. For example, V8's timeline plotter <https://code.google.com/p/v8-wiki/wiki/V8Profiler#Timeline_plot> reports time spent handling IC misses; however getting the required timestamps is so expensive compared to what the functions actually do that it tends to over-report them by about 2x. The sampling profiler <https://code.google.com/p/v8-wiki/wiki/V8Profiler#Command_Line>'s output has a section with "C++ entry points", which include IC miss handlers among other things. It has less (but still non-zero) overhead, and can be rather flaky due to the inherent randomness of sampling. -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups "v8-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
