> On 17 Dec 2016, at 15:23, Sven Van Caekenberghe <s...@stfx.eu> wrote:
>
>
>> On 17 Dec 2016, at 14:28, Henrik Nergaard <henrik.nerga...@uia.no> wrote:
>>
>> This is not a comparable benchmark as the sum in Smalltalk keeps on growing
>> and ends up doing LargeInteger calculations and thus the speed loss, while
>> the c the int just rolls over.
>>
>> Sum in Smalltalk = 500000000500000000
>> Sum in C = -1243309312
>
> Yes, I realised afterwards. Shame on me.
>
> Now, in Pharo 64 bits:
>
> [
> | sum |
> sum:= 0.
> 1 to: 1e9 do: [ :i | sum := sum + i ].
> self assert: sum = (1e9 * (1e9 + 1) / 2) ] timeToRun.
>
> "0:00:00:03.379"
>
> (1e9 * (1e9 + 1) / 2) < SmallInteger maxVal.
>
> "true"
>
> So there the speed difference is way smaller.
And here is a correct C99 version
$ cat bench.c
#include <stdio.h>
#include <time.h>
#include <assert.h>
int main() {
clock_t begin = clock();
long sum = 0;
for (int i = 1; i <= 1000000000; i++)
sum += i;
assert(sum == ((1000000000*1000000001)/2));
clock_t end = clock();
double time_spent = (double)(end - begin) / CLOCKS_PER_SEC;
printf("time_spent=%f\n", time_spent);
}
prometheus:tmp sven$ ./a.out
time_spent=2.393986
>> Best regards,
>> Henrik
>>
>> -----Original Message-----
>> From: Pharo-users [mailto:pharo-users-boun...@lists.pharo.org] On Behalf Of
>> Sven Van Caekenberghe
>> Sent: Saturday, December 17, 2016 2:15 PM
>> To: Any question about pharo is welcome <pharo-users@lists.pharo.org>
>> Subject: Re: [Pharo-users] [Stupid Benchmarks] C++ vs Pharo
>>
>> Like this:
>>
>> [ | sum | sum:= 0. 1 to: 1e9 do: [ :i | sum := sum + i ]. sum ] timeToRun.
>>
>> "0:00:00:39.305"
>>
>> cat bench.c
>>
>> #include <stdio.h>
>> #include <time.h>
>>
>> int main() {
>> clock_t begin = clock();
>>
>> int sum = 0;
>> for (int i = 0; i < 1000000000; i++)
>> sum += i;
>>
>> clock_t end = clock();
>> double time_spent = (double)(end - begin) / CLOCKS_PER_SEC;
>> printf("time_spent=%f\n", time_spent); }
>>
>> ./a.out
>>
>> time_spent=2.370234
>>
>> That is C being 16 times faster ...
>>
>>> On 17 Dec 2016, at 13:49, Sven Van Caekenberghe <s...@stfx.eu> wrote:
>>>
>>> Hmm, this sounds wrong (C++ should be (a lot) faster on such micro
>>> benchmarks).
>>>
>>> You should exclude the executable startup time.
>>>
>>> In Pharo you should do [ .. ] timeToRun and something similar in C/C++.
>>>
>>>> On 17 Dec 2016, at 13:41, Dimitris Chloupis <kilon.al...@gmail.com> wrote:
>>>>
>>>> in multiplication pharo is around 2 times slower compared to C++
>>>>
>>>> #include <stdio.h>
>>>>
>>>> int main()
>>>> {
>>>> double x=1;
>>>> for(double i; i<1000000000 ; ++i)
>>>> {
>>>> x = 0.1*i;
>>>> }
>>>>
>>>> return 1;
>>>> }
>>>>
>>>> time ./testMul
>>>> 3.13 real 3.13 user 0.00 sys
>>>>
>>>> time ./pharo Ephestos.image eval "|x| x := 1. 1 to: 1000000000 do:[:each|
>>>> x := 0.1 * each]"
>>>> 1
>>>> 4.97 real 4.48 user 0.09 sys
>>>>
>>>> On Sat, Dec 17, 2016 at 2:16 PM Dimitris Chloupis <kilon.al...@gmail.com>
>>>> wrote:
>>>> So I was bored and decided to test how fast pharo is compared to C++.
>>>>
>>>> so I tested addition
>>>>
>>>> C++ version:
>>>>
>>>> #include <stdio.h>
>>>>
>>>> int main()
>>>> {
>>>> double x=0;
>>>> while(x<1000000000)
>>>> {
>>>> x = x+1;
>>>> }
>>>>
>>>> return 1;
>>>> }
>>>>
>>>> time ./test1
>>>> 2.84 real 2.84 user 0.00 sys
>>>>
>>>> Pharo version:
>>>>
>>>> time ./pharo Ephestos.image eval "|x| x := 0. 1 to: 1000000000 do:[:each|
>>>> x := x +1]"
>>>> 1
>>>> 2.09 real 1.94 user 0.08 sys
>>>>
>>>> Pharo is +50% faster than C++ ... o_O ... that's suprising, I assume here
>>>> Pharo VM probably does some kind of optimisation.
>>>>
>>>
>>
>>
>>
>
