On Saturday, 29 August 2015 at 13:06:58 UTC, David Nadlinger
wrote:
On Saturday, 29 August 2015 at 12:59:59 UTC, Adam D. Ruppe
wrote:
I'm happy with the codegen the way it is, it is good enough
for me, but let's not make mountains out of hills.
But the fact is that many people are not. Even the core
language team, who doesn't want their compiler to get 30%
slower on the next release.
LOL. I've actually run into a fun problem with the program that I
use to update dmd on my box. It needs root permissions to install
dmd, so it does sudo up front to get the password and then reruns
it before every command to reset the sudo timer. Before dmd
switched to the D front-end, that worked, and I didn't have to
type in my password again. So, I could just kick off the update
program and leave. However, after the switch to D, the Phobos
build and tests take longer than 5 minutes (or whatever the exact
sudo timeout is), and I keep having to rerun my program to update
dmd, because I run it and forget about it, and sudo eventually
times out waiting for me to type in the password and terminates
the update program. If my computer were faster, this wouldn't be
a problem, but it worked prior to the move to D, and it doesn't
now. So, from that standpoint, the 30% loss of speed in dmd is
already costing me.
However, the biggest problem with dmd's slow codegen is probably
ultimately PR. It's the reference compiler, so it's what folks
are going to grab first and what folks are most likely to compare
with their C++ code. That's comparing apples to oranges, but
they'll do it. And a slow dmd will cost us on some level in that
regard. The folks who know what they're doing and care about
performance enough will use ldc or gdc, but it's not what the
newcomers are likely to grab.
- Jonathan M Davis
