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Re: Possible change to gen* for splits
- To: Richard Henderson <rth at cygnus dot com>
- Subject: Re: Possible change to gen* for splits
- From: Richard Earnshaw <rearnsha at arm dot com>
- Date: Thu, 16 Mar 2000 18:41:42 +0000
- Cc: Richard Kenner <kenner at vlsi1 dot ultra dot nyu dot edu>, cpopetz at cygnus dot com, gcc at gcc dot gnu dot org
- Cc: rearnsha at arm dot com
- Organization: ARM Ltd.
- Reply-To: rearnsha at arm dot com
> On Thu, Mar 16, 2000 at 05:05:29PM +0000, Richard Earnshaw wrote:
> > Maybe it would be better if the "glue" were to appear outside of the
> > double quotes. Eg (though I haven't thought the implications of this
> > particular syntax through):
> >
> > +"&& reload_completed"
>
> Can't do that without hacking up read_rtx. We're only prepared
> for certain types of tokens.
>
>
> r~
Ok, how about forgetting the second constraint altogether, and having a
single constraint like
"foo && (RECOG || bar)"
RECOG could always be #define'd to 1 when recognizing a pattern, and to
zero when the constraint is used as a split. The optimizer can then
simplify the expression as required.