On Thursday, December 17, 2015 at 11:26:48 AM UTC-8, Benedikt Meurer wrote: > > Can't you use the same instruction sequence, even from C++ code? >
Yeah, I could, just not using the compiler intrinsics. I was hoping to avoid duplicating the sequence in multiple locations, but it might be the best way. > Or compile a small stub that is callable from C++ directly and thereby use > the same instruction sequence? > Right, this way makes the most sense to me. > Also the code stub should work if that's being used by CS and FCG, while > you can inline the code into TF. You just need to make sure to generate the > exactly the same instructions I guess? > Yeah, I suppose inlining the TF can be a later optimization if desired. > IIRC Jaro thought about this already, maybe he can give some advice. > > On Thu, Dec 17, 2015 at 8:06 PM, Ben Smith <bi...@chromium.org > <javascript:>> wrote: > >> >> >> On Wednesday, December 16, 2015 at 7:16:07 PM UTC-8, Benedikt Meurer >> wrote: >>> >>> You probably need the same guarantees for CS. So how about putting them >>> into a code stub? And calling the stub for the %_ cases in all three >>> compilers? >>> >> >> Yes, that's what I was thinking too, but I was wondering if there was >> another way -- AIUI the code stub has the overhead of a function call for >> all compilers, right? >> >> >>> BTW wouldn't it work if FCG always uses the C++ version? >>> >> >> Maybe I'm misunderstanding when the various compilers are used. But if >> it's possible that some code that was compiled with FCG is being used at >> the same time that compiled with TF is used and they are accessing the same >> shared memory, then it's necessary that they have the same instruction >> sequence. >> >> >>> -- Benedikt >>> >>> Ben Smith <bi...@chromium.org> schrieb am Do., 17. Dez. 2015, 00:01: >>> >>>> Hi v8-dev, >>>> >>>> I added the Atomics API earlier this year (in src/js/harmony-atomics.js >>>> and src/runtime/runtime-atomics.cc). It's currently implemented as runtime >>>> functions using compiler intrinsics. I'd like to add a TurboFan >>>> implementation, but I need to make sure that the generated assembly is the >>>> same in both the full-codegen and for TF. What's the best way to do this? >>>> >>>> FYI, here's the associated bug: >>>> https://bugs.chromium.org/p/v8/issues/detail?id=4614 >>>> >>>> Thanks, >>>> -Ben >>>> >>>> -- >>>> -- >>>> v8-dev mailing list >>>> v8-...@googlegroups.com >>>> 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 v8-dev+un...@googlegroups.com. >>>> For more options, visit https://groups.google.com/d/optout. >>>> >>> -- >> -- >> v8-dev mailing list >> v8-...@googlegroups.com <javascript:> >> 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 v8-dev+un...@googlegroups.com <javascript:>. >> For more options, visit https://groups.google.com/d/optout. >> > > -- -- v8-dev mailing list v8-dev@googlegroups.com 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 v8-dev+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
