On Wed, Jul 30, 2014 at 3:59 PM, Boris Zbarsky <[email protected]> wrote:
> In SpiderMonkey, I'd think the !== version ends up with a getprop IC at > worst and a direct slot load at best, followed by whatever the !== does (if > we're lucky, just a tag test). > FWIW, it's a direct slot load and the !== will be folded because we end up with int32 !== undefined. But as you said, here it's just DCE so it doesn't really matter :) The compiler will also fold typeof int32 -> "number" and then "number" !== "undefined". Jan _______________________________________________ dev-tech-js-engine-internals mailing list [email protected] https://lists.mozilla.org/listinfo/dev-tech-js-engine-internals
