pi benchmark on ldc and dmd

[Adam D. Ruppe]

bearophile wrote:
> In such situations it's never enough to compare the D code compiled
> with DMD to the D code compiled with LDC. You also need a reference
> point, like a C version compiled with GCC (here using GMP bignums).
> Such reference points are necessary to anchor performance
> discussions to something.

Actually, I don't think that would be relevant here.

The thread started with someone saying the DMD backend is garbage
and should be abandoned.

I'm sick and tired of hearing people say that. The Digital Mars
code has many, many advantages over the others*.

But, it was challenged specifically on the optimizer, so to
check that out, I wanted all other things to be equal.

Same code, same front end, same computer, as close to same runtime
and library is possible with different compilers. The only
difference should be the backend so we can draw conclusions about
it without other factors skewing the results.


So for this, I just wanted to compare dmd backend to ldc and
gdc backend so I didn't worry too much about absolute numbers
or other languages. (Actually, one of the reasons I picked the
pi one was after the embarrassing defeat in floating point, I was
hoping dmd could score a second victory and I could follow up
on that "prove it" post with satisfaction. Alas, the facts didn't
work out that way. Though, I still do find dmd to beat g++
on a lot of real world code - things like slices actually make
a sizable difference.)

But regardless, it was just about comparing backends, not
doing language comparisons.

===

* To name a huge one. Today was the first time I ever got ldc
or gdc to actually work on my computer, and it took a long, long
time to do it. I've tried in the past, and failed, so this was
a triumph. Big success.

I was waiting over an hour just for gcc+gdc to compile! In the
time it takes for gcc's configure script to run, you can make
clean, build dmd, druntime and phobos.

It's a huge hassle to get the code together too. I had to go
to *four* different sites to get gdc's stuff together (like 80
MB of crap, compressed!), and two different ones to get even the
ldc binary to work. Pain in my ASS.


And this is on Linux too. I pity the fool who tries to do this
on Windows, knowing how so much linux software treats their
Windows "ports".


I'd like to contrast to dmd: unzip and play with wild abandon.