Use predicates for RTL objects

[Jeff Law]

On 8/8/19 11:06 AM, Arvind Sankar wrote:
> On Thu, Aug 08, 2019 at 08:31:28AM -0600, Jeff Law wrote:
>> True, but they could be.  When David was working in this space a few
>> years ago I concluded that the main value in sub-classing the various
>> RTL operators just wansn't worth the effort.  Instead we focused on
>> starting to tear apart things like the toplevel objects into rtx_insn
>> and the like.  THere's little value in treating those as simple RTXs.
>> INSN_LIST and the like were also ripe for this treatment.
>>
>> The biggest value in making a real class for the operators things would
>> be to move the runtime RTL checking into a compile-time check.  But I
>> couldn't really green light something like that without first completing
>> the rtx_insn changes.
> 
> Are there any notes or old discussion threads on what remains? I would
> be interested in taking a look if no-one else is.
I don't recall if that discussion was internal or external.  If the
latter, then it'd be in the gcc-patches archives.

Jeff