Backend nearly entirely converted to D

[Joakim]

On Wednesday, 7 November 2018 at 15:12:13 UTC, Dukc wrote:
> On Wednesday, 7 November 2018 at 14:39:55 UTC, Joakim wrote:
>> I don't know why you think that would matter: I'm using the 
>> same compilers to build each DMD version and comparing the 
>> build times as the backend was translated to D.
>
> Because generally, LLVM compilers provide faster code, but 
> compile slower than Digital Mars compilers AFAIK. So if you 
> compile the D code with DMD but C code with LDC, the program 
> will likely compile faster but execute slower as increasing 
> portions are written in D, compared to using the same backend 
> for both languages.
>
> I'm not sure if you benchmarked the time used to build DMD, or 
> the time used by generated DMD to compile some other program. 
> If it was the former, the "real" result is probably worse than 
> your results. But if it was the latter, it is likely better.

The former, if it wasn't clear. It's also possible something 
slowed down building the frontend in successive DMD versions, so 
ideally I'd only time building the backend for each DMD version, 
but I haven't looked into that.