Re: [Gomp-discuss] IR hooks ...

[Diego Novillo]

On Wed, 2003-04-02 at 07:59, Lars Segerlund wrote:
> 
>   If you check the gcc mailing list for :
> 
> [RFC] CFG hooks for rtl/tree specificities
> 
>   you will see what I mean, I was refering to Internal Representation, 
> and perhaps some hooks for our stuff would be an easy way to get the 
> patches in ?
> 
>   I.e. we could have some hooks for the trees themself, ( containing the 
> parallell awareness that is required ).
> 
That's not what hooks are used for.  They are used in situations where
functions need to operate on an abstract data structure that may contain
data from different representations in GCC.  A hook is essentially a
function pointer.

Language hooks are very widely used in GCC.  For instance, when parsing
begins, the main compile loop inside gcc calls the function
(*parse_file)() which different front ends initialize to different
parsing functions.

We are now starting to think about hooks for different IR (Intermediate
Representations).  Sebastian is now looking at splitting edges in a
flowgraph, since that needs to do different things in the Tree flow
graph than in the RTL flowgraph.  A hook is the perfect thing to use so
that we can have a generic edge splitter that calls the appropriate
function when dealing with a tree flowg graph and RTL flow graph.

The parallel markers are a different thing.  We will augment the Tree IR
with new nodes.  If we ever need to implement code that deals with
parallel RTL and parallel Trees, then we may write a hook then.


Diego.