Bug 121829 – optimize js splice

• Status: UNCONFIRMED
• Component: JavaScriptCore

[Peng Xinchao]

splice should separte two steps -- shift and unshift. I think "ShiftCountMode" is not necessity.

[Peng Xinchao]

Created attachment 212443 [details]
Array splice should using ArrayStore First.

[Peng Xinchao]

Created attachment 212446 [details]
new patch

[Darin Adler]

Comment on attachment 212443 [details]
Array splice should using ArrayStore First.

View in context: https://bugs.webkit.org/attachment.cgi?id=212443&action=review

> runtime/JSArray.h:100
> -        return shiftCountWithAnyIndexingType(exec, startIndex, count);
> +        if (!shiftCountForShift(exec, startIndex, count)) 
> +            return shiftCountWithAnyIndexingType(exec, startIndex, count);
> +        
> +
> +        return true;

For what it’s worth, the much clearer to write this is:

    return shiftCountForShift(exec, startIndex, count) || shiftCountWithAnyIndexingType(exec, startIndex, count);

[Peng Xinchao]

Created attachment 212953 [details]
make clear code

[Mark Hahnenberg]

I'm confused. What problem is this solving?

[Sam Weinig]

Comment on attachment 212953 [details]
make clear code

r- due to lack of ChangeLog and explanation.