On Aug 7, 2:05 am, "Jack" <[EMAIL PROTECTED]> wrote:
> I know one benchmark doesn't mean much but it's still disappointing to see
> Python as one of the slowest languages in the test:
>
> http://blog.dhananjaynene.com/2008/07/performance-comparison-c-java-p...
That Python code is bad, it contains range() instead of xrange, the
big loop is in the main code instead of inside a function, uses ==
None, etc. That person can try this (with Psyco), I have changed very
little, the code is essentially the same:
import time, psyco
from psyco.classes import __metaclass__
class Person:
def __init__(self, count):
self.count = count
self.prev = None
self.next = None
def shout(self, shout, deadif):
if shout < deadif:
return shout + 1
self.prev.next = self.next
self.next.prev = self.prev
return 1
class Chain:
def __init__(self, size):
self.first = None
last = None
for i in xrange(size):
current = Person(i)
if self.first is None:
self.first = current
if last is not None:
last.next = current
current.prev = last
last = current
self.first.prev = last
last.next = self.first
def kill(self, nth):
current = self.first
shout = 1
while current.next != current:
shout = current.shout(shout, nth)
current = current.next
self.first = current
return current
def main():
ITER = 100000
start = time.time()
for i in xrange(ITER):
chain = Chain(40)
chain.kill(3)
end = time.time()
print 'Time per iteration = %s microseconds ' % ((end - start) *
1000000 / ITER)
psyco.full()
main()
us = microseconds
On my PC (that seems similar to his one) this version needs about 38.9
us/iter instead of 189.
On my PC the Java version takes 1.17 us, while the C++ version (with
MinGW 4.2.1) takes 9.8 us.
A raw D translation needs 14.34 us, while a cleaned up (that uses
structs, no getters/setters) needs 4.67 us.
I don't know why my C++ is so much slow (doing the same things to the C
++ version doesn't change its running time much).
Bye,
bearophile
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