What's left to do for a stable D2?

[Robert Jacques]

On Sun, 24 Jan 2010 21:59:38 -0500, Walter Bright  
<newshound1 at digitalmars.com> wrote:

> dsimcha wrote:
>> Just out of curiosity, how hard is 64-bit to implement given that you  
>> already have
>> a 32-bit compiler?
>
> Shouldn't be that bad. After all, the current code generator survived  
> going from 16 to 32 bits with about 90% of it unchanged.

But don't 16-bit and 32-bit x86 have the same number of registers, while  
x86-64 doubled them? Which should result in ABI changes, etc in addition  
to optimizer changes. Also, FWIW, according to Wikipedia, position  
independent code is also easier and they threw out some old instructions.