Is DMD 2.052 32-bit?

[lurker]

Jonathan M Davis Wrote:

> On Wednesday 09 March 2011 17:56:13 Walter Bright wrote:
> > On 3/9/2011 4:30 PM, Jonathan M Davis wrote:
> > > Much as I'd love to have a 64-bit binary of dmd, I don't think that the
> > > gain is even vaguely worth the risk at this point.
> > 
> > What is the gain? The only thing I can think of is some 64 bit OS
> > distributions are hostile to 32 bit binaries.
> 
> Well, the fact that you then have a binary native to your system is obviously a 
> gain (and is likely the one which people will cite most often), and that _does_ 
> count for quite a lot. However, regardless of that, it's actually pretty easy to 
> get dmd to run out of memory when compiling if you do much in the way of CTFE or 
> template stuff. Granted, fixing some of the worst memory-related bugs in dmd will 
> go a _long_ way towards fixing that, but even if they are, you're theoretically 
> eventually supposed to be able to do pretty much anything at compile time which 
> you can do at runtime in SafeD. And using enough memory that you require the 64-
> bit address space would be one of the things that you can do in SafeD when 
> compiling for 64-bit. As long as the compiler is only 32-bit, you can't do that 
> at compile time even though you can do it at runtime (though the current 
> limitations of CTFE do reduce the problem in that you can't do a lot of stuff at 
> compile time period).
> 
> In any case, the fact that dmd runs out of memory fairly easily makes having a 
> 64-bit version which could use all of my machine's memory really attractive. And 
> honestly, having an actual, 64-bit binary to run on a 64-bit system is something 
> that people generally want, and it _is_ definitely a problem to get a 32-bit 
> binary into the 64-bit release of a Liunx distro.
> 
> Truth be told, I would have thought that it would be a given that there would be 
> a 64-bit version of dmd when going to support 64-bit compilation and was quite 
> surprised when that was not your intention.

I think porting DMD to 64 bits would be a pragmatic solution to this. Computers are getting more memory faster than Walter is able to fix possible leaks in DMD. There's awful lots of template and CTFE code using more than 2 or 3 GB of RAM. I can't even imagine how one could develop some modern application if this was a hard limit. Luckily there are GDC and LDC, which allow enterprise users to take full advantage of the 24-64 GB available.

Some simple use case would be Facebook's infrastructure. Assume Andrei wanted to rewrite it all in D. Probably more than 100M LOC. Would need hundreds of gigabytes of RAM to compile. It would also take days to compile, and maybe 50% less on a 64 bit system.