Re: Has the CVM interprerter code been rolled into libjit?

On Sun, 2006-12-17 at 10:42 +0800, Deryk Robosson wrote:
> On 12/17/06, Eric Engler <[email protected]> wrote:
> 
> > Is the CVM still a viable model, or has it been super-ceded by libjit? I
> > understand libjit can fallback to interpretation on a platform that doesn't
> > have JIT support yet, but I'm fuzzy on the mechanics of this. Can the
> > current C# compiler still generate CVM code as an option?
> 
> The CVM is default and libjit can be chosen to be used at compile time
> (of pnet).
> 
> Now, if cscc can be passed an option to use one or the other, I'm not
> aware of.  One of the compiler people would have to answer that one.

Not a person who works on either the compiler or the runtime, but a
compiler-literate individual who's been following the project for a
while.

The Portable.NET runtime consumes "CIL" instructions, which as you say
above are designed to be Just-In-Time compiled, not directly
interpreted.

The CVM interpreter in the original run-time design 'compiled' CIL
instructions to CVM instructions, then interpreted the latter.

The libjit version of the runtime compiles the CIL instructions to
either machine code or to a libjit interpreter, which has no connection
to the old CVM interpreter.

The compiler emits CIL instructions only, and has no awareness of any of
this.

Hope this helps.