Luau Files

Another week, another release - happy October! 🎃

What's Changed

• Skip subtyping reasoning that is never read by @Pyseph in https://github.com/luau-lang/luau/pull/2992
• Skip two type traversals whose results are unused by @Pyseph in https://github.com/luau-lang/luau/pull/3006
• Fix GC allocation rate underflow when the heap shrinks between cycles by @gemtool in https://github.com/luau-lang/luau/pull/2996

New Contributors

• @Pyseph made their first contribution in https://github.com/luau-lang/luau/pull/2992

Analysis

• Fix a bug that was preventing jump-to-definition functionality from working on function return annotations.
• Resolve a crash that could occur when using type assertions within a typeof call inside a type alias.

Compiler / NCG

• Add new tracking logic that allows local registers to be reused after their last use.
• NCG: Guard against register counter overflow.
• NCG: Fix a bug in the buffer range checking logic.

Bytecode graph

• Preserve phi registers in loops during inlining.
• Fix bugs relating to how the bytecode graph models loop instructions' interactions with values.
• Add a representation of feedback slots to the bytecode graph.

Runtime / C API

• Rename lua_setbuffercage to lua_setmemorycage.

Full Changelog: https://github.com/luau-lang/luau/compare/0.740...0.741

Co-authored-by: Andy Friesen afriesen@roblox.com Co-authored-by: Ariel Weiss arielweiss@roblox.com Co-authored-by: Hunter Goldstein hgoldstein@roblox.com Co-authored-by: Sora Kanosue skanosue@roblox.com Co-authored-by: Thomas Schollenberger tschollenberger@roblox.com Co-authored-by: Vyacheslav Egorov vegorov@roblox.com