Re: [ANN] Lua 5.4.0 (work2) now available

[tobias@...]

Quoting tobias@justdreams.de:

> Quoting Luiz Henrique de Figueiredo <lhf@tecgraf.puc-rio.br>:
>
> > The focus of Lua 5.4.0 is performance. We're especially interested in
> > feedback about its performance but all feedback is welcome. Thanks.
> > --lhf
>
> I have silly little piece of code I use to compare language performance.
> Includes I/O and arrays(table in Lua obviously). When called with 20
> iterations Lua 5.4 runs 5.8s vs 7.8s in Lua 5.3. That's quite a
> significant performance jump! That is looking awesome!

Here is the code, in case someone is wondering:

#!/usr/bin/env lua

-- based on code by Erik Wrenholt

local BAILOUT        = 16
local MAX_ITERATIONS = 1000
local RESOLUTION     = 40
local RESFLOAT       = 40 / 1.0
local RESLOW         = 1-RESOLUTION
local RESHGH         = RESOLUTION-2
local write, clock, format = io.write, os.clock, string.format


local iterate = function( x, y )
	local cr = y-0.5
	local zi = 0.0
	local zr = 0.0

	for i = 0, MAX_ITERATIONS do
		local tmp = zr * zi
		local zr2 = zr * zr
		local zi2 = zi * zi
		zr = zr2  - zi2  + cr
		zi = tmp + tmp + x
		--print(zr,zi)
		if (zi2+zr2 > BAILOUT) then
			return ' '
		end
	end
	return '*'
end

local mandelbrot = function( n )
	while n>0 do
		for y = RESLOW, RESHGH do
			local output = { }
			for x = RESLOW, RESHGH do
				output[ x+RESOLUTION ] = iterate( x/RESFLOAT, y/RESFLOAT )
			end
			print( table.concat( output, '' ) );
		end
		n = n-1
	end
end

local n = 1
if arg[1] then
	n = tonumber( arg[ 1 ] )
end

local t = clock()
mandelbrot( n )
print( format( "Lua Time Elapsed %.2f", clock() - t ) )