Battle-plan for CTFE

[Jacob Carlborg via Digitalmars-d-announce]

On 2016-05-09 18:57, Stefan Koch wrote:
> Hi Guys,
>
> I have been looking into the DMD now to see what I can do about CTFE.
> Unfortunately It is a pretty big mess to untangle.
> Code responsible for CTFE is in at least 3 files.
> [dinterpret.d, ctfeexpr.d, constfold.d]
> I was shocked to discover that the PowExpression actually depends on
> phobos! (depending on the exact codePath it may or may not compile...)
> which let to me prematurely stating that it worked at ctfe
> [http://forum.dlang.org/thread/ukcoibejffinknrbzktv@forum.dlang.org]
>
> My Plan is as follows.
>
> Add a new file for my ctfe-interpreter and update it gradually to take
> more and more of the cases the code in the files mentioned above was
> used for.
>
> Do Dataflow analysis on the code that is to be ctfe'd so we can tell
> beforehand if we need to store state in the ctfe stack or not.
>
> Or baring proper data-flow analysis: RefCouting the variables on the
> ctfe-stack could also be a solution.
>
> I will post more details as soon as I dive deeper into the code.

I was listening to a discussion Don and Daniel had about the current 
implementation of CTFE. They talked about using a byte code interpreter. 
Even implementing a really crappy byte code interpreter would be a huge 
improvement.

-- 
/Jacob Carlborg