Program size, linking matter, and static this()

[Denis Shelomovskij]

21.12.2011 0:22, Walter Bright пишет:
> First off, dmd most definitely puts 0 initialized static data into the
> BSS segment. So what's going on here?
>
> 1. char data is not initialized to 0, it is initialized to 0xFF.
> Non-zero data cannot be put in BSS.
Sorry, it was because of copying C code in my post. ubyte array was 
tested in D.
>
> 2. Static data goes, by default, into thread local storage. BSS data is
> not thread local. To put it in global data, it has to be declared with
> __gshared.
I completely forgot about TLS.
>
> So,
>
> __gshared byte arr[1024 * 1024 *10];
>
> will go into BSS.
>
> There is pretty much no reason to have such huge arrays in static data.
> Instead, dynamically allocate them.
Of course, it was just an example of a huge executable.


Now I see that dmd uses BSS , thank you for the explanation!

I still think that zero-filled TLS arrays can occupy no size in the 
executable, but it should be done with compiler and D run-time system 
support and surely it is not worth the time it will take to implement.

I apologize for the unfair accusation.