Re: [ANN] LuaJIT Roadmap 2012/2013
- From: Geoff Leyland <geoff_leyland@xxxxxxxxxxx>
- To: luajit@xxxxxxxxxxxxx
- Date: Thu, 14 Jun 2012 10:22:42 +1200
On 14/06/2012, at 9:45 AM, Adam Strzelecki wrote:
> Thanks for clarifying that. I recall the discussion from Feb this year:
> http://lua-users.org/lists/lua-l/2012-02/msg00207.html
> where you've said that allocation sinking with native vector (& SIMD matrix)
> types may be solution to avoid temporary allocations for matrix/vector
> expressions.
>
> But now it seems this isn't the case, at least not the goal of allocation
> sinking here.
>
> Can you please give more details then what is the main goal for upcoming
> allocation sinking? (some sample)
I'm hoping it'll transform this:
point = {}
function point:new(x, y)
self.__index = self
return setmetatable({x=x, y=y}, self)
end
function point.__add(a, b)
return point:new(a.x + b.x, a.y + b.y)
end
do
local a, b = point:new(1, 1), point:new(2, 2)
for i = 1, 1000 do
a = (a + b) + b
end
io.stderr:write(a.x, ", ", a.y)
end
into this:
do
local ax, ay, bx, by = 1, 1, 2, 2
for i = 1, 1000 do
ax = ax + bx + bx
ay = ay + by + by
end
io.stderr:write(ax, ", ", ay)
end
It's not that tables are moved from the heap to the stack, it's that now there
are no tables at all. (and when it does I'll rewrite that raytrace benchmark
to use point objects)
Other related posts:
