FOLDOC definition

[RobG]

Thomas 'PointedEars' Lahn wrote: [...]
The name of this group infers it.

That is probably the stupidest thing you have ever said.

You really are tiresome. Keep beating your drum, you're the only one
marching to that beat.

Why isn't the group called "com.lang.ecmascript"? Because most
discussion is about ECMAScript ECMAScript as implemented in browsers,
generally refered to as JavaScript or javascript.

Rubbish.  "JavaScript" is the name of one implementation and it is a
trademark.  Period.

Perhaps you post here purely for the sske of argument. I'm over it.

 

[Jorge]

I wouldn't want anything too short. Micro-benchmarks generally suck
at showing anything relevant for actual use.

You could check out the computer language shootout (although I think
it's a little misleading to allow a Java implementation that is one
just JNI call to native code).

Well, this "Micro-benchmark" falls clearly in the "too short" class,
but...

The results:

C: 126.5 MHz i386/32
C: 126.5 MHz x86/64
FF3.6: 29.3 MHz FireBug OFF
Chrome5.0.307.9: 26.8 MHz
v8-shell: 25.4 MHz version 2.1.1.1
FF3.5.8 21.2 MHz FireBug OFF
jsc: 9.0 MHz javascriptCore shell
Safari4.0.4: 7.9 MHz javascriptCore
Safari4.0.4: 1.8 MHz webInspector console
FF 3.0.15: 1.7 MHz FireBug OFF
Opera 10.5: 1.3 MHz
Opera 9.64: 1.2 MHz
Opera 10.10: 1.1 MHz
FF3.6: 0.6 MHz FireBug Console
Chrome5.0.307.9: 0.6 MHz Developer Tools console
FF2.0.0.20: 0.2 MHz FireBug OFF


The source code:

**********************************************
javascript:
var k= 20e6; n= k, v= 0, t= +new Date();

while (n) {
v+= n/2/n;
n--;
}

t= +new Date() -t;
(this.alert || this.print)([(k/t/1e3).toFixed(1)+ " MHz", t+" ms",
v]);




**********************************************
C:
volatile int RUN= 1;

void alrmHandler (int status) {
RUN= 0;
}

int main (int argc, char* argv[]) {
double ctr= 0;
double v= 0;
struct itimerval timer;
timer.it_interval.tv_sec= timer.it_interval.tv_usec= 0;
timer.it_value.tv_usec= 0;
timer.it_value.tv_sec= 1;

signal(SIGALRM, alrmHandler);
setitimer(ITIMER_REAL, &timer, 0);

while (RUN) {
ctr++;
v+= ctr/2/ctr;
}

fprintf(stdout, "%.1f MHz, %.1f\n", ctr/1e6, v);
fflush(stdout);
return 0;
}

 

[Jorge]

Is there any point?

Such comparisons only really matter where you have a choice of doing
something in both languages and other criteria for discrimination are
(more-or-less) equal.

For example, if the objective is a program that can be downloaded and
run in most browsers, C is probably a not a consideration no matter
how much faster it runs. On the other hand, if the requirement is for
complex server-side processing, javascript probably isn't in the race
as it doesn't have any built-in input/output mechanism and is
dependent on a suitable host environment. If requirements indicate a
scripting language, a platform-native shell script may be the best
choice.

Do you have a proposed scenario?

The ratio of processing power between them is changing every day. JS's
processing power has increased in a few years in more than 2 orders of
magnitude. It's still not (and will never be) as fast as a finely-
tuned C program (*) could be. But, you need to know better in order to
be able to decide -when JS is a viable option- where to draw the line
that separates what's possible/advisable to do with it, and what's
not.

(*)A finely-tuned C program -that very likely- is going to take to
write many times as long as in a higher-level dynamic language -with
all the bells and whistles- such as e.g. JS.