> 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.
> 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.
>>>
>>
>
>
>
