DMD backend quality (Was: Re: DIP 1031--Deprecate Brace-Style Struct Initializers--Community Review Round 1 Discussion)

[Walter Bright]

On 2/20/2020 12:35 PM, Dibyendu Majumdar wrote:
> I used to think that the backend should be abandoned in favour of LLVM but no 
> more. I think it is worth having a fast backend. I was surprised how quickly dmd 
> can be compiled compared to LLVM.
> 
> It is excellent for a language designer to have full control over the 
> implementation too as it helps play with ideas without having to fight with 
> external libraries.

I might add that having a fast edit-compile-debug loop is indeed transformative. 
Sometimes tracking down a problem may require hundreds of times through that loop.

On my dev machine, a full debug build of dmd takes 43 seconds.

An incremental build (one file change) takes 9 seconds.

(The build compiler is a Windows 32 bit dmd built with dmd.)