It seems the optimizer of Digital Mars is horribly out of date. I just tested it with some code, and it performs worse than even the non-commercial, one-man project Pelles C or lccwin32.

The generated code is 100% (!) slower than the code generated by GCC, and as I said even a little slower than the code produced
by those part-time compilers.

I am kinda surprised, considering DM's commercial roots, I expected it to perform at a level somewhere between Pelles C
and GCC.

Or maybe I am just using the wrong flags? This is my first
attempt to compile something with this compiler, so maybe
that's the case. I am trying to build a C (not C++) Win32 console application here, P5 instruction set, and I use:

dmc -5 -o+all demo.c grid.c

demo.c and grid.c are the two files which contain the
source code.

It works fine, except for the horrible performance..

Em 1/2/2011 23:16, copx escreveu:
> It seems the optimizer of Digital Mars is horribly out of date. I just
> tested it with some code, and it performs worse than even the
> non-commercial, one-man project Pelles C or lccwin32.
>
> The generated code is 100% (!) slower than the code generated by GCC,
> and as I said even a little slower than the code produced
> by those part-time compilers.
>
> I am kinda surprised, considering DM's commercial roots, I expected it
> to perform at a level somewhere between Pelles C
> and GCC.
>
> Or maybe I am just using the wrong flags? This is my first
> attempt to compile something with this compiler, so maybe
> that's the case. I am trying to build a C (not C++) Win32 console
> application here, P5 instruction set, and I use:
>
> dmc -5 -o+all demo.c grid.c
>
> demo.c and grid.c are the two files which contain the
> source code.
>
> It works fine, except for the horrible performance..
>
>
Without specific information this post does not bring any chance to receive an answer which will be helpful be it for you or the groups of users of DM compiler.

Please send a link to a place where 'demo.c' and 'grid.c' could be downloaded.

If the sources are not possible to be disclosed, then find an example of a public available source that in your opinion demonstrates clearly the problem[s] you're complaining.

Without data its is not possible any diagnostic.

"Cesar Rabak"  wrote in message news:iiceg8$21m8$1@digitalmars.com... [snip remark about poor optimizer performance]
>> dmc -5 -o+all demo.c grid.c
>>
>> demo.c and grid.c are the two files which contain the
>> source code.
>>
>> It works fine, except for the horrible performance..
>>
>Without specific information this post does not bring any chance to receive an answer which will be helpful be it for you or the groups of users of DM compiler.

The original post probably was a little unclear because it
mixed my surprise about the poor optimizer performance with my actual question.

I basically just want to know how to make dmc produce
fully optimized binaries. According to the command line help
and what little documentation is available for free at the DM
website the above command line seems correct. I am just
asking here to make sure that I did not miss some vital flag. The optimizer performance is what it is.

Em 2/2/2011 18:51, copx escreveu:
>
>
> "Cesar Rabak" wrote in message news:iiceg8$21m8$1@digitalmars.com...
> [snip remark about poor optimizer performance]
>>> dmc -5 -o+all demo.c grid.c
>>>

BTW, where did you find the flag "+all" in the optimization switch?

>>> demo.c and grid.c are the two files which contain the
>>> source code.
>>>
>>> It works fine, except for the horrible performance..
>>>
>> Without specific information this post does not bring any chance to
>> receive an answer which will be helpful be it for you or the groups of
>> users of DM compiler.
>
> The original post probably was a little unclear because it
> mixed my surprise about the poor optimizer performance with my actual
> question.
>
Indeed.  The problem is that you insist in this approach:

> I basically just want to know how to make dmc produce
> fully optimized binaries.

Which would be what? You know, "fully optimized" is as informative as "horrible performance".

You need to inform what are the attributes you're after in your program so the right set of actions can taken to achieve a goal.

> According to the command line help
> and what little documentation is available for free at the DM
> website the above command line seems correct.

There is no way to insure it is correct or no, without knowing your requirements and the nature of the source code.

> I am just
> asking here to make sure that I did not miss some vital flag. The
> optimizer performance is what it is.
>

The flags are vital or not accordingly to goals for the compiled code, which you insist in not sharing, so it is impossible to determine that.

The only way we can assess your complaints is understanding the issue[s].  To do so we need to see them.

"Cesar Rabak"  wrote in message news:iicicl$29h2$1@digitalmars.com... 
>BTW, where did you find the flag "+all" in the optimization switch?

http://www.digitalmars.com/ctg/ctgOptimizer.html

Quote:
"Use +all to optimize your code to the fullest extent. "

>Indeed.  The problem is that you insist in this approach:

I think the issue is that you are either an idiot or an asshole.

>> I basically just want to know how to make dmc produce
>> fully optimized binaries.
>
>Which would be what? You know, "fully optimized" is as informative as "horrible performance".

See above. Either you are amazingly stupid or you are just pretending to misunderstand to waste my time. The meaning of phrases and words in human communication depends on context. My first post made it
absolutely clear that I am talking about optimizing for speed here.
Notice the "slower than" as opposed to "bigger than".
"Fully optimized" in this context thus can only mean the correct
flags for "optimize for speed" builds. Notice that even the Digital Mars
website I quoted uses the "non-informative" expression
"to optimize your code to the fullest extent." which is just a more
verbose form of "to fully optimize your code". That they are talking about
fully optimized for speed here becomes clear only if you look at the
context. Which is no problem provided the reader isn't you.

I am not going to waste further time with you.

Em 2/2/2011 20:56, copx escreveu:
>
>
> "Cesar Rabak" wrote in message news:iicicl$29h2$1@digitalmars.com...
>> BTW, where did you find the flag "+all" in the optimization
>> switch?
>
> http://www.digitalmars.com/ctg/ctgOptimizer.html
>
> Quote: "Use +all to optimize your code to the fullest extent. "
>
>> Indeed. The problem is that you insist in this approach:
>
> I think the issue is that you are either an idiot or an asshole.

Let me give you an important clue: insulting me will not magically solve
the problems of yours.

You insist in not explaining the problem, and only gets annoyingly
repetitive in keeping in the route on non helping others to help you.

Now, you broke another barrier and went rude.

>
>>> I basically just want to know how to make dmc produce fully
>>> optimized binaries.
>>
>> Which would be what? You know, "fully optimized" is as informative
>> as "horrible performance".
>
> See above. Either you are amazingly stupid or you are just pretending
> to misunderstand to waste my time.

You are wasting the time of anyone who decides to pay attention to this
thread.

> The meaning of phrases and words in human communication depends on
> context.

Which you systematically refuse to give. Right?

> My first post made it absolutely clear that I am talking about
> optimizing for speed here.

Speed of what? How did you measure it? Where is a code sample so we can
look at and see if the sample warrants your conclusions? If the specific
code is some pathologic case or is triggering a behaviour in the
toolchain which brings the results you see, but no one else can see!?

> Notice the "slower than" as opposed to "bigger than".

Ok. Exact figures? Platform?

> "Fully optimized" in this context thus can only mean the correct
> flags for "optimize for speed" builds.

No, it can mean anything until the exact meaning gets understood by all
the parties involved in the dialogue.

> Notice that even the Digital Mars website I quoted uses the
> "non-informative" expression "to optimize your code to the fullest
> extent." which is just a more verbose form of "to fully optimize your
> code". That they are talking about fully optimized for speed here
> becomes clear only if you look at the context. Which is no problem
> provided the reader isn't you.
>
The context provided by the web page you referenced is more complete as
the "full extent" is adequately described in the page as an alias for a
set of optimization techniques.

> I am not going to waste further time with you.

Without giving enough information on your problem is a waste of your
time to post just complaining and dodging to inform minimally how to reproduce your problem.

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