Performance dmd vs ldc2

Chris wendlec at tcd.ie
Wed Jul 24 06:29:01 PDT 2013


On Wednesday, 24 July 2013 at 13:12:46 UTC, John Colvin wrote:
> On Wednesday, 24 July 2013 at 12:49:50 UTC, Chris wrote:
>> On Wednesday, 24 July 2013 at 12:11:50 UTC, bearophile wrote:
>>> Chris:
>>>
>>>> ldmd2 compiles the code much faster than ldc2 (~4 secs vs 14 
>>>> secs). The program runs just as fast (as far as I can see at 
>>>> the moment).
>>>
>>> The ldmd2 binary is tiny, it's not a compiler, it's just a 
>>> wrapper. If the compilation time is different then they are 
>>> can calling the compiler with different compilation switches.
>>>
>>> Bye,
>>> bearophile
>>
>> Thanks for clarifying that. I am still impressed with the 
>> performance. Although I'm sure I could squeeze a bit more out 
>> of dmd. As of now I'm only using the garden-variety (i.e. dmd 
>> -release [files]). I didn't use any switches with ldc2, though.
>
> try dmd -release -noboundscheck -O -inline [files]
> and the same for ldmd

Just tried it. dmd takes a bit longer to compile. Little or no 
performance gain in executable. Executable with ldmd2 still 
lightning fast in comparison.

I expected a slight gain in performance with ldc2, but nowhere 
near as big a gain as I actually got. Here's a new fan! However, 
the rest of the code (except for the loading bit) seems to work 
as fast with dmd as with ldc2.

What's the story with LDC for Windows?


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