868422 - Add UnsafeArrayCopy intrinsic for selfhosted code

Status: RESOLVED WONTFIX

(Core :: JavaScript Engine, defect)

Description

[Felix S. Klock II [:pnkfelix, :fklock]]

There are spots in ParallelArray.js where we have for-loops that copy substrings (i.e. contiguous subsequences) from one array to another.

That should be an intrinsic operation (that we make super-fast).

Comment 1

[Felix S. Klock II [:pnkfelix, :fklock]]

1. I meant that these are copying substrings from one *dense* array to another *dense* array.

2. We would want the intrinsic to work on Typed Arrays as well.  (That or have a separate intrinsic for the typed array cases, if that ends up being a better strategy.)