Re: LuaJIT with vectors

[Mike Pall <mikelu-1011@...>]

Petri Häkkinen wrote:
> For example,
> 
> normalize(mul(transformMat, vec1 + vec2))
> 
> is very convenient syntax, and something I've been using with C++ and
> shaders.
> 
> What do you think, is the LuaJIT compiler smart enough to eliminate these
> allocs?

Not yet. But adding escape analysis plus generalized store sinking
and allocation sinking is on my TODO list for a long time.

> But as a commercial game developer I would be very concerned about the
> alloc/gc overhead.

That's speculation and/or premature optimization. Of course such
overhead is easily demonstrable in isolated benchmarks. But I'd
need to see hard numbers from full-game profiling before I'd
consider this to be a serious issue.

> I'm talking about pushing
> LuaJIT to extremes here, so that only a minimal core would need to be
> implemented in C++.

Actually we're in violent agreement here. You just revealed my
plan for world domination. Dang!

> Yes, I agree. Bloating the size of all values is not a good solution. I was
> wondering would it be somehow magically possible to only make the vector
> type bigger without adding the overhead to all other types?

Sorry, I'm not a magician. I only play one on this list.

--Mike