[JSC] String substring operation should return ropes consistently
Created attachment 369541 [details]
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Created attachment 369580 [details]
Comment on attachment 369580 [details]
Committed r245194: <https://trac.webkit.org/changeset/245194>
Ah, my investigation was wrong.
While memory reduction is real, the effect comes from the fact that JSRopeString is cheaper than JSString + StringImpl. Not related StringImpl's substring sharing feature.
So, maybe, we should just prefer JSRopeString for substring cases.