On Mar 02, 2004 at 10:28 +1030, Peter Loveday wrote:
From my experience gcc (and therefore I assume mingw?) produces far
less
efficient code than MSVC, or better still, Intel's compiler. I'd
prefer to
see this used.
A performance argument begs for a performance measurement. I tried
lua-5.0.1 on my Windows machine, compiled with mingwin gcc-3.2.3 and
MSVC7, on a couple of (randomly selected) test programs from The Great
Computer Language Shootout. I pumped up the iteration counts to get
decent timings. The MSVC7 version of lua was compiled with /O2 (the
default Release flag) and the mingwin version of lua was compiled with
-O2. Also, the MSVC7 version is compiled as a monolithic .exe, while
the mingwin version is from luacheia, which has lua and lualib as
DLL's.
The results are inconclusive; gcc is faster on one benchmark; MSVC7 is
faster on the other. Details:
tulrich@tulrich /cygdrive/c/thatcher/lua-5.0.1
$ time ../luacheia/product/lib/lua5.exe hash2.lua # this is mingwin
compiled
1 9999 1 9999
real 0m9.777s
user 0m0.031s
sys 0m0.000s
tulrich@tulrich /cygdrive/c/thatcher/lua-5.0.1
$ time lua/Release/lua.exe hash2.lua # this is MSVC7 compiled
1 9999 1 9999
real 0m9.121s
user 0m0.031s
sys 0m0.000s
tulrich@tulrich /cygdrive/c/thatcher/lua-5.0.1
$ time ../luacheia/product/lib/lua5.exe sieve.lua # this is mingwin
compiled
Count: 1028
real 0m3.187s
user 0m0.015s
sys 0m0.000s
tulrich@tulrich /cygdrive/c/thatcher/lua-5.0.1
$ time lua/Release/lua.exe sieve.lua # this is MSVC7 compiled
Count: 1028
real 0m4.447s
user 0m0.015s
sys 0m0.015s
tulrich@tulrich /cygdrive/c/thatcher/lua-5.0.1
$
---- hash2.lua ----
-- $Id: hash2.lua,v 1.2 2001/01/11 14:52:55 doug Exp $
-- http://www.bagley.org/~doug/shootout/
-- with help from Roberto Ierusalimschy
local n = tonumber((arg and arg[1]) or 1)
local hash1={}
for i=0,1000000 do
hash1["foo_"..i] = i
end
local hash2={}
for i=1,n do
for k,v in hash1 do
hash2[k] = v + (hash2[k] or 0)
end
end
io.write(string.format("%d %d %d %d\n", hash1["foo_1"],
hash1["foo_9999"],
hash2["foo_1"], hash2["foo_9999"]))
---- sieve.lua ----
-- $Id: sieve.lua,v 1.10 2001/07/11 17:58:14 doug Exp $
-- http://www.bagley.org/~doug/shootout/
--
-- Roberto Ierusalimschy pointed out the for loop is much
-- faster for our purposes here than using a while loop.
function main(num)
local flags = {}
for num=num,1,-1 do
count = 0
for i=2,8192 do
flags[i] = 1
end
for i=2,8192 do
if flags[i] == 1 then
for k=i+i, 8192, i do
flags[k] = 0
end
count = count + 1
end
end
end
end
NUM = tonumber((arg and arg[1])) or 1000
count = 0
main(NUM)
io.write("Count: ", count, "\n")
----
--
Thatcher Ulrich
http://tulrich.com
