Profiling DMD's Compilation Time with dmdprof

[Manu]

On Wed, Nov 7, 2018 at 10:30 PM Vladimir Panteleev via
Digitalmars-d-announce <digitalmars-d-announce at puremagic.com> wrote:
>
> On Thursday, 8 November 2018 at 06:08:20 UTC, Vladimir Panteleev
> wrote:
> > It was definitely about 4 seconds not too long ago, a few years
> > at most.
>
> No, it's still 4 seconds.
>
> digger --offline --config-file=/dev/null -j auto -c
> local.cache=none build     7.31s user 1.51s system 203% cpu 4.340
> total
>
> > It does seem to take more time now; I wonder why.
>
> If it takes longer, then it's probably because it's being built
> in one CPU core, or in the release build.

https://youtu.be/msWuRlD3zy0

DMD only builds with one core, since it builds altogether.
And all builds are release builds... what good is a debug build? DMD
is unbelievably slow in debug. If it wasn't already slow enough... if
I try and build with a debug build, it takes closer to 5 minutes.

I suspect one part of the problem is that DMD used to be built with a
C compiler, and now it's built with DMD... it really should be built
with LDC at least?