Now that I think about it, you can probably do this without support from the runtime by interposing the handful of runtime functions that invalidate the method cache…
Saagar Jha > On Dec 16, 2019, at 00:23, Jean-Daniel <mail...@xenonium.com> wrote: > > My bad, I just see that when rereading the description. Of course, it will > requires an updated runtime. > >> Le 16 déc. 2019 à 09:21, Saagar Jha <saa...@saagarjha.com >> <mailto:saa...@saagarjha.com>> a écrit : >> >> There’s also a check for method swizzling and other invalidation, assuming >> that there is cooperation from the runtime. Unless I’m misunderstanding what >> you mean by the selector changing? >> >> Saagar Jha >> >>> On Dec 16, 2019, at 00:16, Jean-Daniel <mail...@xenonium.com >>> <mailto:mail...@xenonium.com>> wrote: >>> >>> >>>> Le 16 déc. 2019 à 06:05, Saagar Jha <saa...@saagarjha.com >>>> <mailto:saa...@saagarjha.com>> a écrit : >>>> >>>> It’s been a while, but I just thought you both might be interested in some >>>> follow-up I did for this idea. I implemented it for fun in clang >>>> <https://github.com/saagarjha/expresscall> and it turns out that it’s a >>>> pretty decent performance win >>>> <https://saagarjha.com/blog/2019/12/15/bypassing-objc-msgsend/> over >>>> objc_msgSend, both because it dispatches faster and because the compiler >>>> can do a full inline through it. >>> >>> Yes, but you don't preserve the objc_msgSend semantic. >>> >>> If I understand you code correctly, all you do is checking if it is the >>> same ISA, which does not guarantee in anyway that the selector did not >>> change since the previous call. >>> >>> As classes are fully dynamic and methods can be swizzle, you must perform a >>> full IMP lookup for every calls, which complexly defeat the purpose of >>> inline caching. >>> >> > _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
