On Tuesday, 6 November 2018 at 22:12:02 UTC, Walter Bright wrote:
With the recent merging of the last of the big files machobj.d:
https://github.com/dlang/dmd/pull/8911
I'm happy to say we're over the hump in converting the backend
to D!
Great! Although I wish it didn't have to be you mostly doing this
grunt work.
Remaining files are minor: tk.c, cgen.c, dt.c, fp.c, os.c,
outbuf.c, sizecheck.c, strtold.c and mem.c. I'll probably leave
a couple in C anyway - os.c and strtold.c. sizecheck.c will
just go away upon completion.
Thanks to everyone who helped out with this!
Of course, the code remains as ugly as it was in C. It'll take
time to bit by bit refactor it into idiomatic D.
I just benchmarked building the last couple versions of DMD, when
most of the backend was converted to D, by building them with the
latest DMD 2.083.0 official release and clang 6.0 in a
single-core linux/x64 VPS. Here are the times I got, best of 3
runs for each:
2.081.2 - 11.5s
2.082.1 - 10.5s
2.083.0 - 9.9s
master - 10.8s
Not quite the gains hoped for, particularly with those last large
files you just converted to D seemingly slowing compilation down,
but maybe it will get better with refactoring and when the entire
backend is compiled at once, rather than the DMD separate
compilation used now.
The more immediate benefit is to get rid of all the parallel .h
files, which were a constant source of bugs when they didn't
match the .d versions.
I was going to ask why you wouldn't need those headers for your
C/C++ compiler, DMC, but it looks like you've translated that to
mostly D already:
https://github.com/DigitalMars/Compiler/tree/master/dm/src/dmc
