What does the -betterC switch in dmd do?

[TheFlyingFiddle via Digitalmars-d-learn]

The description in dmd help says: omit generating some runtime 
information and helper functions.


What runtime information are we talking about here?  My 
understanding is that it's basically an experimental feature but 
when (if) completed what subset of the language would still be 
usable?

Re: OSX Foundation framework D binding

[Jacob Carlborg via Digitalmars-d-learn]

On 2015-11-12 06:50, Vadim Lopatin wrote:


Aren't there any ready set of translated and post-processed files for
main OSX foundations in some repository? Could you point at it?


I have these 6 years old bindings [1] which uses an old Objective-C 
bridge. Perhaps it's possible to do some search-and-replace to convert 
the bindings to use the new Objective-C support.


There's the Dive Framework [2] as well. It uses a fork of the compiler 
which has all the Objective-C interoperability features that the 
upstream compiler will eventually have.


[1] http://dsource.org/projects/dstep/browser/dstep
[2] https://github.com/DiveFramework/DiveFramework

--
/Jacob Carlborg

Re: OSX Foundation framework D binding

[ponce via Digitalmars-d-learn]

On Wednesday, 11 November 2015 at 16:06:57 UTC, Jacob Carlborg 
wrote:

On 2015-11-11 10:29, Daniel Kozak via Digitalmars-d-learn wrote:

I find only this one: 
http://code.dlang.org/packages/derelict-cocoa


Also, there's no point in complicate the bindings by using 
function pointers like this.


Opinion.
I only ever got problems with bindings that aren't dynamic.

For example that problem would not happen with dynamic loading.
https://github.com/nomad-software/x11/issues/11

Re: my first D program (and benchmark against perl)

[Daniel Kozak via Digitalmars-d-learn]

On Wednesday, 11 November 2015 at 13:32:00 UTC, perlancar wrote:
Here's my first non-hello-world D program, which is a direct 
translation from the Perl version. I was trying to get a feel 
about D's performance:


...

While I am quite impressed with how easy I was able to write D, 
I am not so impressed with the performance. Using rdmd (build 
20151103), the D program runs in 17.127s while the Perl version 
runs in 11.391s (so the D version is quite a bit *slower* than 
Perl's). While using gdc (Debian 4.9.2-10), I am able to run it 
in 3.988s (only about 3x faster than Perl's version).


I understand that string processing (concatenation, allocation) 
is quite optimized in Perl, I was wondering if the D version 
could still be sped up significantly?


Main problem is with allocations and with stripLeft, here is my 
version which is 10x faster than perls even with DMD. With LDC is 
12x faster


import std.stdio;
import std.array : appender;
import std.range;


auto fmttable(T)(T table) {
 auto res = appender!(string)();
 res.reserve(64);

 if (table.length == 0) return "";

 // column widths
 auto widths = new int[](table[0].length);

 foreach (rownum, row; table) { 
 foreach (colnum, cell; row) {  
 if (cell.length > widths[colnum])
widths[colnum] = cast(int)cell.length;
 }
 }

 foreach (row; table) {
 res.put("|");
 foreach (colnum, cell; row) {
 int l = widths[colnum] - cast(int)cell.length;
 res.put(cell);
 if (l)
 res.put(' '.repeat().take(l)); 
 res.put("|");
 }
 res.put("\n");
 }

 return res.data;
}

void main() {

auto table = [
["row1.1", "row1.2  ", "row1.3"],
["row2.1", "row2.2", "row2.3"],
["row3.1", "row3.2", "row3.3  "],
["row4.1", "row4.2", "row4.3"],
["row5.1", "row5.2", "row5.3"],
];

write(fmttable(table));
for (int i=0; i < 100; ++i) {
fmttable(table);
}
}

Re: How to fix "Error symbol '.....' is already defined"

[Kagamin via Digitalmars-d-learn]

Looks like a bug in the compiler.

Re: my first D program (and benchmark against perl)

[Daniel Kozak via Digitalmars-d-learn]

V Thu, 12 Nov 2015 09:12:32 +
Daniel Kozak via Digitalmars-d-learn
 napsáno:

> On Wednesday, 11 November 2015 at 13:32:00 UTC, perlancar wrote:
> > Here's my first non-hello-world D program, which is a direct 
> > translation from the Perl version. I was trying to get a feel 
> > about D's performance:
> >
> > ...
> >
> > While I am quite impressed with how easy I was able to write D, 
> > I am not so impressed with the performance. Using rdmd (build 
> > 20151103), the D program runs in 17.127s while the Perl version 
> > runs in 11.391s (so the D version is quite a bit *slower* than 
> > Perl's). While using gdc (Debian 4.9.2-10), I am able to run it 
> > in 3.988s (only about 3x faster than Perl's version).
> >
> > I understand that string processing (concatenation, allocation) 
> > is quite optimized in Perl, I was wondering if the D version 
> > could still be sped up significantly?  
> 
> Main problem is with allocations and with stripLeft, here is my 
> version which is 10x faster than perls even with DMD. With LDC is 
> 12x faster
> 
> import std.stdio;
> import std.array : appender;
> import std.range;
> 
> 
> auto fmttable(T)(T table) {
>   auto res = appender!(string)();
>   res.reserve(64);
> 
>   if (table.length == 0) return "";
> 
>   // column widths
>   auto widths = new int[](table[0].length);
> 
>   foreach (rownum, row; table) {
> foreach (colnum, cell; row) { 
>   if (cell.length > widths[colnum])
>   widths[colnum] = cast(int)cell.length;
>   }
>   }
> 
>   foreach (row; table) {
>   res.put("|");
>   foreach (colnum, cell; row) {
>   int l = widths[colnum] - cast(int)cell.length;
>   res.put(cell);
>   if (l)
>res.put('
> '.repeat().take(l)); res.put("|");
>   }
>   res.put("\n");
>   }
> 
>   return res.data;
> }
> 
> void main() {
>   
>   auto table = [
>   ["row1.1", "row1.2  ", "row1.3"],
>   ["row2.1", "row2.2", "row2.3"],
>   ["row3.1", "row3.2", "row3.3  "],
>   ["row4.1", "row4.2", "row4.3"],
>   ["row5.1", "row5.2", "row5.3"],
>   ];
> 
>   write(fmttable(table));
>   for (int i=0; i < 100; ++i) {
>   fmttable(table);
>   }
> }
> 
> 

or with ~ operator:

import std.stdio;

auto fmttable(string[][] table) {

import std.array : appender, uninitializedArray;
import std.range : take, repeat;
import std.exception : assumeUnique;

auto res = appender(uninitializedArray!(char[])(128));
res.clear();
 
if (table.length == 0) return "";
// column widths
auto widths = new int[](table[0].length);

foreach (rownum, row; table) {   
foreach (colnum, cell; row) { 
if (cell.length > widths[colnum])
widths[colnum] = cast(int)cell.length;
}  
} 

foreach (row; table) {
res ~= "|";
foreach (colnum, cell; row) {
int l = widths[colnum] - cast(int)cell.length;
res ~= cell;
if (l) 
res ~= ' '.repeat().take(l);
res ~= "|";
}
res.put("\n");
}

 return res.data.assumeUnique();
}

void main() {

auto table = [
["row1.1", "row1.2  ", "row1.3"],
["row2.1", "row2.2", "row2.3"],
["row3.1", "row3.2", "row3.3  "],
["row4.1", "row4.2", "row4.3"],
["row5.1", "row5.2", "row5.3"],
];

write(fmttable(table));
for (int i=0; i < 100; ++i) {
fmttable(table);
}
}

Re: What does the -betterC switch in dmd do?

[Justin Whear via Digitalmars-d-learn]

On Thu, 12 Nov 2015 19:37:41 +, TheFlyingFiddle wrote:

> The description in dmd help says: omit generating some runtime 
> information and helper functions.
> 
> What runtime information are we talking about here?  My 
> understanding is that it's basically an experimental feature but 
> when (if) completed what subset of the language would still be 
> usable?

I believe the purpose of the switch is to help folks who are trying to 
write for bare or embedded systems by not emitting references to the D 
runtime library and runtime module information.  Whether it actually does 
that in its current implementation is another question.

Re: my first D program (and benchmark against perl)

[Daniel Kozak via Digitalmars-d-learn]

V Thu, 12 Nov 2015 11:03:38 +
Tobias Pankrath via Digitalmars-d-learn
 napsáno:

> > or with ~ operator:
> >
> > import std.stdio;
> >
> > [...]  
> 
> Did anyone check that the last loop isn't optimized out?

Yes, it is not optimized out

> Could also be improved further if you make the function take an
> output range and reuse one appender for every call, but that might be
> to far off the original perl solution.

I agree, that would be to far off the original solution.

Re: my first D program (and benchmark against perl)

[perlancar via Digitalmars-d-learn]

On Wednesday, 11 November 2015 at 14:20:51 UTC, Rikki Cattermole 
wrote:
I turned it into mostly using large allocations, instead of 
small ones.
Although I'd recommend using Appender instead of my custom 
functions for this.


Oh and for me, I got it at 2 secs, 513 ms, 397 μs, and 5 
hnsecs. Unoptimized, using dmd.
When release mode is enabled on dmd: 1 sec, 550 ms, 838 μs, and 
9 hnsecs. So significant improvement even with dmds awful 
optimizer.


Hi Rikki,

Thanks. With your version, I've managed to be ~4x faster:

dmd  : 0m1.588s
dmd (release): 0m1.010s
gdc  : 0m2.093s
ldc  : 0m1.594s

Perl version : 0m11.391s

So, I'm satisfied enough with the speed for now. Turns out dmd is 
not always slower.

Re: Compiler doesn't complain with multiple definitions

[anonymous via Digitalmars-d-learn]

On 12.11.2015 06:27, ric maicle wrote:

I was playing with __traits and tried the code below.
Shouldn't the compiler emit a warning that I'm defining isPOD
multiple times and/or I'm defining something that is built-in
like isPOD?

// DMD64 D Compiler v2.069
import std.stdio;

struct isPOD {
bool status = false;
}

int main()
{
 byte isPOD = 0;
 writeln(isPOD);
 writeln(__traits(isPOD, typeof(isPOD)));
 return 0;
}


__traits has special syntax. The first "argument" must be from a list of 
special keywords that only have special meaning in that place. You can't 
put the name of a struct there, and you can't put the special keyword 
anywhere else. So there's no ambiguity, and you're not redefining 
anything. Everything's fine.

Re: my first D program (and benchmark against perl)

[perlancar via Digitalmars-d-learn]

On Wednesday, 11 November 2015 at 14:26:32 UTC, Andrea Fontana 
wrote:

Did you try rdmd -O -noboundscheck -release yourscript.d ?


I just did. It improves speed from 17.127s to 14.831s. Nice, but 
nowhere near gdc/ldc level.


You should try using appender!string rather than concatenate 
(http://dlang.org/phobos/std_array.html#.Appender) using 
capacity 
(http://dlang.org/phobos/std_array.html#.Appender.capacity) to 
improve performace.



You should also switch from for to foreach.


Thanks for the above 2 tips.

Re: my first D program (and benchmark against perl)

[Daniel Kozak via Digitalmars-d-learn]

V Thu, 12 Nov 2015 12:13:10 +
perlancar via Digitalmars-d-learn 
napsáno:

> On Wednesday, 11 November 2015 at 14:20:51 UTC, Rikki Cattermole 
> wrote:
> > I turned it into mostly using large allocations, instead of 
> > small ones.
> > Although I'd recommend using Appender instead of my custom 
> > functions for this.
> >
> > Oh and for me, I got it at 2 secs, 513 ms, 397 μs, and 5 
> > hnsecs. Unoptimized, using dmd.
> > When release mode is enabled on dmd: 1 sec, 550 ms, 838 μs, and 
> > 9 hnsecs. So significant improvement even with dmds awful 
> > optimizer.  
> 
> Hi Rikki,
> 
> Thanks. With your version, I've managed to be ~4x faster:
> 
> dmd  : 0m1.588s
> dmd (release): 0m1.010s
> gdc  : 0m2.093s
> ldc  : 0m1.594s
> 
> Perl version : 0m11.391s
> 
> So, I'm satisfied enough with the speed for now. Turns out dmd is 
> not always slower.

It depends which flags do you use on ldc and gdc


ldc (-singleobj -release -O3 -boundscheck=off)
gdc (-O3 -finline -frelease -fno-bounds-check)

Re: OSX Foundation framework D binding

[Jacob Carlborg via Digitalmars-d-learn]

On 2015-11-12 09:34, ponce wrote:


Opinion.
I only ever got problems with bindings that aren't dynamic.

For example that problem would not happen with dynamic loading.
https://github.com/nomad-software/x11/issues/11


I've never encountered that problem.

--
/Jacob Carlborg

Re: my first D program (and benchmark against perl)

[Tobias Pankrath via Digitalmars-d-learn]

or with ~ operator:

import std.stdio;

[...]


Did anyone check that the last loop isn't optimized out? Could 
also be improved further if you make the function take an output 
range and reuse one appender for every call, but that might be to 
far off the original perl solution.

Re: How to fix "Error symbol '.....' is already defined"

[Vincent R via Digitalmars-d-learn]

On Thursday, 12 November 2015 at 08:45:57 UTC, Kagamin wrote:

Looks like a bug in the compiler.


In this case it means there is a bug inside dmd and gdc (didn't 
try ldc)...

Re: my first D program (and benchmark against perl)

[Daniel Kozak via Digitalmars-d-learn]

On Thursday, 12 November 2015 at 12:25:08 UTC, Daniel Kozak wrote:

V Thu, 12 Nov 2015 12:13:10 +
perlancar via Digitalmars-d-learn 


napsáno:

On Wednesday, 11 November 2015 at 14:20:51 UTC, Rikki 
Cattermole wrote:

> I turned it into mostly using large allocations, instead of
> small ones.
> Although I'd recommend using Appender instead of my custom
> functions for this.
>
> Oh and for me, I got it at 2 secs, 513 ms, 397 μs, and 5
> hnsecs. Unoptimized, using dmd.
> When release mode is enabled on dmd: 1 sec, 550 ms, 838 μs, 
> and

> 9 hnsecs. So significant improvement even with dmds awful
> optimizer.

Hi Rikki,

Thanks. With your version, I've managed to be ~4x faster:

dmd  : 0m1.588s
dmd (release): 0m1.010s
gdc  : 0m2.093s
ldc  : 0m1.594s

Perl version : 0m11.391s

So, I'm satisfied enough with the speed for now. Turns out dmd 
is not always slower.


It depends which flags do you use on ldc and gdc


ldc (-singleobj -release -O3 -boundscheck=off)
gdc (-O3 -finline -frelease -fno-bounds-check)


import std.stdio;

auto fmttable(string[][] table) {

import std.array : appender, uninitializedArray;
import std.range : take, repeat;
import std.exception : assumeUnique;


if (table.length == 0) return "";
// column widths
auto widths = new int[](table[0].length);
	size_t total = (table[0].length + 1) * table.length + 
table.length;	


foreach (rownum, row; table) {
foreach (colnum, cell; row) {
if (cell.length > widths[colnum])
widths[colnum] = cast(int)cell.length;
}
}

foreach (colWidth; widths)
{
total += colWidth * table.length;
}   

auto res = appender(uninitializedArray!(char[])(total));
res.clear();

foreach (row; table) {
res ~= "|";
foreach (colnum, cell; row) {
int l = widths[colnum] - cast(int)cell.length;
res ~= cell;
if (l)
res ~= ' '.repeat().take(l);
res ~= "|";
}
res.put("\n");
}

 return res.data.assumeUnique();
}

void main() {

auto table = [
["row1.1", "row1.2  ", "row1.3"],
["row2.1", "row2.2", "row2.3"],
["row3.1", "row3.2", "row3.3  "],
["row4.1", "row4.2", "row4.3"],
["row5.1", "row5.2", "row5.3"],
];

writeln(fmttable(table));
for (int i=0; i < 100; ++i) {
fmttable(table);
}
}

dmd -O -release -inline -boundscheck=off  asciitable.d

real0m1.463s
user0m1.453s
sys 0m0.003s


ldc2 -singleobj -release -O3 -boundscheck=off asciitable.d

real0m0.945s
user0m0.940s
sys 0m0.000s

gdc -O3 -finline -frelease -fno-bounds-check -o asciitable 
asciitable.d


real0m0.618s
user0m0.613s
sys 0m0.000s


perl:

real0m14.198s
user0m14.170s
sys 0m0.000s

Re: win32 from master: unicode functions by default?

[Mike Parker via Digitalmars-d-learn]

On Thursday, 12 November 2015 at 15:58:53 UTC, Jonathan M Davis 
wrote:

On Thursday, November 12, 2015 05:08:24 Mike Parker via



version=Unicode on the compiler command line.


It seems pretty wrong for the A versions to be the default 
though...


Still, even in C++ code, I've generally taken the approach of 
using the W functions explicitly in order to avoid any 
potential problems with A functions being called accidentally. 
Regardless, the whole A vs W thing with Win32 is not exactly 
one of its nicer features. :|


- Jonathan M Davis


I've gotten into the same habit. But it appears the switch to 
dynamic loading has made it so that only the A versions or only 
the W versions are available. You no longer get both.


https://github.com/D-Programming-Language/druntime/blob/master/src/core/sys/windows/w32api.d#L85

Re: my first D program (and benchmark against perl)

[Daniel Kozak via Digitalmars-d-learn]

On Thursday, 12 November 2015 at 12:49:55 UTC, Daniel Kozak wrote:
On Thursday, 12 November 2015 at 12:25:08 UTC, Daniel Kozak 
wrote:

... 
auto res = appender(uninitializedArray!(char[])(total));
res.clear();
...


this is faster for DMD and ldc:

auto res = appender!(string)();
res.reserve(total);

but for gdc(fronend version 2.066) it makes it two times slower 
(same for dmd, ldc 2.066 and older)

Re: Compiler doesn't complain with multiple definitions

[ric maicle via Digitalmars-d-learn]

On Thursday, 12 November, 2015 07:50 PM, anonymous wrote:

__traits has special syntax. The first "argument" must be from a list of
special keywords that only have special meaning in that place. You can't
put the name of a struct there, and you can't put the special keyword
anywhere else. So there's no ambiguity, and you're not redefining
anything. Everything's fine.


Thanks for clarifying __traits.

On another thing. I'm wondering why the compiler didn't issue a warning
on struct isPOD and byte isPOD? Isn't this called 'shadowing' or have I
misunderstood the term?

Re: win32 from master: unicode functions by default?

[Jonathan M Davis via Digitalmars-d-learn]

On Thursday, November 12, 2015 05:08:24 Mike Parker via Digitalmars-d-learn 
wrote:
> On Thursday, 12 November 2015 at 04:58:42 UTC, Andre wrote:
> > Hi,
> >
> > by using the win32 library from master, the functions aliases
> > to the ansi windows functions (...A) instead of the unicode
> > functions (...W).
> > Is there a way to control this behavior beside using the
> > explicit function
> > names (A/W)?
> >
> > Kind regards
> > André
>
> version=Unicode on the compiler command line.

It seems pretty wrong for the A versions to be the default though...

Still, even in C++ code, I've generally taken the approach of using the W
functions explicitly in order to avoid any potential problems with A
functions being called accidentally. Regardless, the whole A vs W thing with
Win32 is not exactly one of its nicer features. :|

- Jonathan M Davis

Re: Compiler doesn't complain with multiple definitions

[John Colvin via Digitalmars-d-learn]

On Thursday, 12 November 2015 at 15:06:26 UTC, ric maicle wrote:

On Thursday, 12 November, 2015 07:50 PM, anonymous wrote:
__traits has special syntax. The first "argument" must be from 
a list of
special keywords that only have special meaning in that place. 
You can't
put the name of a struct there, and you can't put the special 
keyword
anywhere else. So there's no ambiguity, and you're not 
redefining

anything. Everything's fine.


Thanks for clarifying __traits.

On another thing. I'm wondering why the compiler didn't issue a 
warning
on struct isPOD and byte isPOD? Isn't this called 'shadowing' 
or have I

misunderstood the term?


If I remember correctly:

Shadowing globals is allowed, all other instances of shadowing 
are not.

Re: my first D program (and benchmark against perl)

[perlancar via Digitalmars-d-learn]

On Thursday, 12 November 2015 at 12:49:55 UTC, Daniel Kozak wrote:

dmd -O -release -inline -boundscheck=off  asciitable.d

real0m1.463s
user0m1.453s
sys 0m0.003s


ldc2 -singleobj -release -O3 -boundscheck=off asciitable.d

real0m0.945s
user0m0.940s
sys 0m0.000s

gdc -O3 -finline -frelease -fno-bounds-check -o asciitable 
asciitable.d


real0m0.618s
user0m0.613s
sys 0m0.000s


perl:

real0m14.198s
user0m14.170s
sys 0m0.000s


Nice! Seems like I can get a further 100% improvement in speed 
from the last version (so a total of ~8x speedup from my original 
D version). Now I wonder how C would fare...