• alkor <alkor au.ru> Dec 23 2009
• =?ISO-8859-1?Q?=22J=E9r=F4me_M=2E_Berger=22?= <jeberger free.fr> Dec 23 2009
• alkor <alor au.ru> Dec 23 2009
• Travis Boucher <boucher.travis gmail.com> Dec 23 2009
• alkor <alkor au.ru> Dec 23 2009
• Travis Boucher <boucher.travis gmail.com> Dec 23 2009

alkor <alkor au.ru> writes:

maybe, i do something wrong, but for example:

$ cat main.d
int main () {
    return 0;
}

$dmd -O -release -ofmain-dmd main.d
$gdc -O3 main.d -o main-gdc
$ ls -l main-dmd main-gdc
-rwxr-xr-x 1 alkor alkor 123439 Dec 23 14:06 main-dmd
-rwxr-xr-x 1 alkor alkor 609363 Dec 23 14:06 main-gdc

why the main-gdc in 5 time more then the main-dmd?

any test shows dmd superiorities over gdc (and gcc)
dmd rules :)

== Repost the article of Travis Boucher (boucher.travis gmail.com)
== Posted at 2009/12/23 04:48 to digitalmars.D

If you can't get gdc to generate optimized code, then you are using it
wrong.

=?ISO-8859-1?Q?=22J=E9r=F4me_M=2E_Berger=22?= <jeberger free.fr> writes:

Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: quoted-printable

alkor wrote:
 maybe, i do something wrong, but for example:
=20
 $ cat main.d
 int main () {
     return 0;
 }
=20
 $dmd -O -release -ofmain-dmd main.d
 $gdc -O3 main.d -o main-gdc
 $ ls -l main-dmd main-gdc
 -rwxr-xr-x 1 alkor alkor 123439 Dec 23 14:06 main-dmd
 -rwxr-xr-x 1 alkor alkor 609363 Dec 23 14:06 main-gdc
=20
 why the main-gdc in 5 time more then the main-dmd?
=20


the gdc command line or use gdmd with the same options as dmd.

	Moreover, since you are trying to optimize for space rather than=20
performance, you should use -Os (or at least -O2) rather than -O3.

 any test shows dmd superiorities over gdc (and gcc)
 dmd rules :)
=20



		Jerome
--=20
mailto:jeberger free.fr
http://jeberger.free.fr
Jabber: jeberger jabber.fr

alkor <alor au.ru> writes:

oh no - both files aren't stripped

after strip a difference is 2,3 times 
$ strip main-gdc main-dmd
$ ls -l main-dmd main-gdc
-rwxr-xr-x 1 alkor alkor  65088 Dec 23 16:44 main-dmd
-rwxr-xr-x 1 alkor alkor 155784 Dec 23 16:44 main-gdc

and main-gdc required libgcc_s.so.1

$ ldd main-gdc
        linux-gate.so.1 =>  (0xffffe000)
        libm.so.6 => /lib/libm.so.6 (0xb7ee7000)
        libgcc_s.so.1 => /usr/local/lib/libgcc_s.so.1 (0xb7edc000)
        libpthread.so.0 => /lib/libpthread.so.0 (0xb7ec4000)
        libc.so.6 => /lib/libc.so.6 (0xb7d89000)
        /lib/ld-linux.so.2 (0xb7f2d000)

--- the next test - math performance ---
module test.performance;

import std.stdio, std.random;
const int MAX = 10000000;
int main () {
    int[] a = new int[MAX];
    int[] b = new int[MAX];
    double[] c = new double[MAX];

    for (auto i=0;  i< MAX; i++) {
	a[i] = i | 0xa1c0;
	b[i] = i | 0xbadbad;
    }

    for (auto i=0;  i< MAX; i++) {
	c[i] = (a[i] & 0x10) ? cast(double)a[i] * b[i] * b[i] : cast(double)a[i] *
a[i] * b[i];
    }
    writefln("init a[9555000] 0x%08X", a[9555000]);
    writefln("init b[9555000] 0x%08X", b[9555000]);
    writefln("init b[9555000] %f", c[9555000]);
    return 0;
}
$ dmd -O -release -oftest-dmd test-performance.d && strip test-dmd
$ time ./test-dmd
init a[9555000] 0x0091EDF8           
init b[9555000] 0x00BBDFBD           
init b[9555000] 1449827528761239666688.000000

real    0m0.722s
user    0m0.552s
sys     0m0.168s

$ gdc  -O3 test-performance.d -o test-gdc && strip test-gdc
$ time ./test-gdc
init a[9555000] 0x0091EDF8
init b[9555000] 0x00BBDFBD
init b[9555000] 1449827528761239666688.000000

real    0m0.786s
user    0m0.628s
sys     0m0.152s

so, dmd's code optimization rules 
Walter made nice lang & good compiler - it's true

Jérôme M. Berger Wrote:

 alkor wrote:
 maybe, i do something wrong, but for example:
 
 $ cat main.d
 int main () {
     return 0;
 }
 
 $dmd -O -release -ofmain-dmd main.d
 $gdc -O3 main.d -o main-gdc
 $ ls -l main-dmd main-gdc
 -rwxr-xr-x 1 alkor alkor 123439 Dec 23 14:06 main-dmd
 -rwxr-xr-x 1 alkor alkor 609363 Dec 23 14:06 main-gdc
 
 why the main-gdc in 5 time more then the main-dmd?
 


 the gdc command line or use gdmd with the same options as dmd.
 
 	Moreover, since you are trying to optimize for space rather than 
 performance, you should use -Os (or at least -O2) rather than -O3.
 
 any test shows dmd superiorities over gdc (and gcc)
 dmd rules :)
 


 
 		Jerome
 -- 
 mailto:jeberger free.fr
 http://jeberger.free.fr
 Jabber: jeberger jabber.fr
 
 

Travis Boucher <boucher.travis gmail.com> writes:

alkor wrote:
 $ dmd -O -release -oftest-dmd test-performance.d && strip test-dmd
 $ gdc  -O3 test-performance.d -o test-gdc && strip test-gdc
 so, dmd's code optimization rules 
 Walter made nice lang & good compiler - it's true
 



Add -frelease to gdc (if you want a fair comparison), and look at the 
code generated rather then running a micro benchmark on something that 
takes a fraction of a second to run.

alkor <alkor au.ru> writes:

thanks,  w -frelease gdc makes a good result - faster then dmd's one & normal
size

Travis Boucher Wrote:

 alkor wrote:
 $ dmd -O -release -oftest-dmd test-performance.d && strip test-dmd
 $ gdc  -O3 test-performance.d -o test-gdc && strip test-gdc
 so, dmd's code optimization rules 
 Walter made nice lang & good compiler - it's true
 


 
 Add -frelease to gdc (if you want a fair comparison), and look at the 
 code generated rather then running a micro benchmark on something that 
 takes a fraction of a second to run.

Travis Boucher <boucher.travis gmail.com> writes:

alkor wrote:
 thanks,  w -frelease gdc makes a good result - faster then dmd's one & normal
size
 


Thats because -frelease removes certain array bounds checking code, 
assertion testing and I think a few other things.