Simplification of combine patterns with subreg and zero_extract

[Rask Ingemann Lambertsen]

On Thu, 13 Apr 2006 13:29:13 +0200, Paolo Bonzini wrote
> > Also, is there a function for simplifying a zero_extract?
> 
> What combine is doing is to expand compound operations such as 
> zero_extract, simplifying them, and try to make new compound 
> operations.   Therefore you should first try to understand what's 
> causing combine to miss the simplification.

I think it is simply because combine.c doesn't have any code to simplify this kind of expression. 

> However, if you add these simplifications to simplify-rtx.c, it will 
> be picked up by combine.

There is a lot of simplification code in combine.c too. Should I try to add these simplifications to both combine.c and simplify-rtx.c?

-- 
Rask Ingemann Lambertsen