RFC: 40 bit integer support

[Bernd Schmidt]

On 07/01/11 22:04, Joseph S. Myers wrote:
> I should add: make the type, the new mode, the testcases etc. entirely 
> target-specific; target-independent GCC should not need to know or care 
> about the specifics of this type.  It's bad enough target-independent GCC 
> knowing about HImode, SImode, DImode and TImode outside default target 
> hook implementations for targets that use those modes.

The idea here is that there is more than one target that supports 40 bit
operations, so why shouldn't we have support for it in
target-independent code and libgcc? It differs from QI/HI/SImode etc. in
that the precision is known and not target-specific.

> And is there anything wrong with the existing PDImode name?

PDImode is so far always defined as MODE_PARTIAL_INT which is handled
quite differently (i.e. by not handling it very much at all). IMO it
would be a bad idea to overload the name.


Bernd