Re: [DotGNU]Will unrolling an instruction slow down execution ?

[Gopal V]

If memory serves me right, Rhys Weatherley wrote:
> The biggest source of slowdown in the engine right now is the overhead of 
> method calls, which involve several non-unrolled instructions (call/callvirt, 
> set_num_args, ckheight, and cknull).  I've experimented with unrolling these, 
> but not enough is gained to make it worth it.
> 
> We will have to move to a real JIT coder to reduce the overhead further.  
> i.e. completely change the representation of stack frames.  

Rhys I've been looking at the object code generated in the cvm.o native
code ?. Just to obtain a view of what we need to do generate for object 
instructions. Would it be fair to assume that generating that chunk or a 
very similar chunk of code in the unroll section would work ?.

The assumption being that we will be able to call the necessary functions 
from assembly ?.

Anyway I think that should make the choice of instructions by the JIT
designed a lot easier , even if the code is not directly usable ...

> That's step 3 in the "generic unroller, dual coders, real JIT" plan.

Okie dokie.

Gopal
-- 
The difference between insanity and genius is measured by success