860557 - Shrink ArrayBuffers

Status: RESOLVED INVALID

(Core :: JavaScript Engine, defect)

Description

[Steve Fink [:sfink] [:s:]]

Currently, ArrayBuffers are created with kind=FINALIZE_OBJECT16_BACKGROUND, with as many fixed slots as they can. This is both wasteful of space for small buffers, and requires special-casing code to ignore the slot data when looking at it for GC purposes. Arrays use a trick where they report 0 fixed slots, are initially given a shape with FINALIZE_OBJECT0, but then use a different kind when they are created.

Or something like that.

ArrayBuffers probably ought to use the same trick as Arrays, for less special-casing.

Comment 1

[Steve Fink [:sfink] [:s:]]

The storage for ABs has been redone many times in many ways at this point, and the wasted space is long gone. (Still not as much sharing as I'd like between different object types, but that's for a different bug.)