Re: Lua/LuaJIT2 performance on Android
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- Subject: Re: Lua/LuaJIT2 performance on Android
- From: Mike Pall <mikelu-1104@...>
- Date: 2011年4月19日 00:36:53 +0200
Josh Haberman wrote:
> Mike Pall <mikelu-1104 <at> mike.de> writes:
> > Oh, well. Floating-point benchmarks are not a good way to compare
> > soft-float VMs. Maybe try again with fannkuch or nsieve.
>
> Where is the right place to obtain these? The official
> shootout website does not seem to list nsieve anymore, and
> has "fannkuch-redux" but not "fannkuch" (are they the same
> thing?)
The two fannkuchs just have a different output. The benchmarks are
rather short, so I'm attaching them here for future archival. You
get nsieve-bit as a bonus. Run them with a scaling factor of 7 for
nsieve and 9 for fannkuch to get reasonable execution times on ARM.
--Mike
-- Lua benchmark: fannkuch-redux. Written by Mike Pall. Public domain.
local function fannkuch(n)
local p, q, s, sign, maxflips, sum = {}, {}, {}, 1, 0, 0
for i=1,n do p[i] = i; q[i] = i; s[i] = i end
repeat
-- Copy and flip.
local q1 = p[1] -- Cache 1st element.
if q1 ~= 1 then
for i=2,n do q[i] = p[i] end -- Work on a copy.
local flips = 1
repeat
local qq = q[q1]
if qq == 1 then -- ... until 1st element is 1.
sum = sum + sign*flips
if flips > maxflips then maxflips = flips end -- New maximum?
break
end
q[q1] = q1
if q1 >= 4 then
local i, j = 2, q1 - 1
repeat q[i], q[j] = q[j], q[i]; i = i + 1; j = j - 1; until i >= j
end
q1 = qq; flips = flips + 1
until false
end
-- Permute.
if sign == 1 then
p[2], p[1] = p[1], p[2]; sign = -1 -- Rotate 1<-2.
else
p[2], p[3] = p[3], p[2]; sign = 1 -- Rotate 1<-2 and 1<-2<-3.
for i=3,n do
local sx = s[i]
if sx ~= 1 then s[i] = sx-1; break end
if i == n then return sum, maxflips end -- Out of permutations.
s[i] = i
-- Rotate 1<-...<-i+1.
local t = p[1]; for j=1,i do p[j] = p[j+1] end; p[i+1] = t
end
end
until false
end
local n = tonumber(arg and arg[1]) or 3
local sum, flips = fannkuch(n)
io.write(sum, "\nPfannkuchen(", n, ") = ", flips, "\n")
-- Lua benchmark: nsieve. Written by Mike Pall. Public domain.
local function nsieve(p, m)
for i=2,m do p[i] = true end
local count = 0
for i=2,m do
if p[i] then
for k=i+i,m,i do p[k] = false end
count = count + 1
end
end
return count
end
local N = tonumber(arg and arg[1]) or 1
if N < 2 then N = 2 end
local primes = {}
for i=0,2 do
local m = (2^(N-i))*10000
io.write(string.format("Primes up to %8d %8d\n", m, nsieve(primes, m)))
end
-- Lua benchmark: nsieve-bit. Written by Mike Pall. Public domain.
local bit = require("bit")
local band, bxor, rshift, rol = bit.band, bit.bxor, bit.rshift, bit.rol
local function nsieve(p, m)
local count = 0
for i=0,rshift(m, 5) do p[i] = -1 end
for i=2,m do
if band(rshift(p[rshift(i, 5)], i), 1) ~= 0 then
count = count + 1
for j=i+i,m,i do
local jx = rshift(j, 5)
p[jx] = band(p[jx], rol(-2, j))
end
end
end
return count
end
local N = tonumber(arg and arg[1]) or 1
if N < 2 then N = 2 end
local primes = {}
for i=0,2 do
local m = (2^(N-i))*10000
io.write(string.format("Primes up to %8d %8d\n", m, nsieve(primes, m)))
end