ARM first & default LDC

[Max Haughton]

On Saturday, 19 December 2020 at 17:15:40 UTC, claptrap wrote:
> On Saturday, 19 December 2020 at 14:20:45 UTC, aberba wrote:
>> On Friday, 18 December 2020 at 00:13:41 UTC, claptrap wrote:
>>> On Thursday, 17 December 2020 at 23:16:33 UTC, Walter Bright 
>>> wrote:
>>>> On 12/17/2020 2:02 AM, claptrap wrote:
>>>>> And lets be honest if LLVM doesnt support it, it's pretty 
>>>>> small potatoes, who's going to go to that kind of effort to 
>>>>> add some niche architecture to DMD?
>>>>
>>>> Win64 was never small potatoes.
>>>
>>> So some years ago DMD had a single target that LLVM did not, 
>>> and how does it look today?
>>
>> For an average D developer, DMD is just the way to go. And the 
>> development time is more iterative than release. So DMD speed 
>> is a must have for development.
>>
>> Average Joe needs DMD.
>
> Average Joe doesnt exist.
>
> Dont get me wrong, I agree 100% that fast compile is a very 
> desirable feature. What I disagree with is the idea that DMD 
> gives people the freedom to add support for new architectures 
> that they wouldn't otherwise have.
>
> 1. Arm support is probably the most desirable, and yet DMD 
> doesnt have it, because it's a lot of work, and well I dont 
> know personally but it sounds like doing anything with the DMD 
> backend is a bit of a nightmare. IE. Freedom to do something is 
> not the same as the thing actually being done.
>
> 2. People could just add it to LLVM if they want i think. Might 
> even be easier to write a whole new backend from scratch, i 
> dont know. IE. Not having DMD doesnt preclude the benefit that 
> Walter claims DMD gives us.

Writing a new backend would probably be easier.

You definitely can add new architectures to DMD (they're not all 
that different these days), i.e. the instruction scheduler isn't 
particularly unreadable, but the dual benefit of having a generic 
code generator to use in D and a clean backend in DMD is pretty 
nice.

It's a huge job, though.