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Re: PATCH RFC: My version of the lower-subreg patch


Rask Ingemann Lambertsen <rask@sygehus.dk> writes:

> On Fri, Dec 15, 2006 at 06:05:25PM -0800, Ian Lance Taylor wrote:
> > Anyhow, I wanted to put this patch out for comments, to see what
> > people think of it.
> 
>    I would like to have an option -f[no-]lower-subreg so I can easily
> compile code with and without the subreg lowering pass for comparison
> purposes.

Good idea.  In the version I just sent out I added -fsplit-wide-types,
defaulting to on with -O1 and above.  I didn't use the name
-flower-subreg because I don't think it is meaningful to users.  I'd
be happy to hear other suggestions for the option name.

>  so I applied this on top of your patch:

Thanks, I added this.

>    So the change is rejected, which trips the assert. I solved it by
> reordering the two movhi variants. Other targets might run into the same
> issue.

Interesting issue.  I think most targets will handle this just by
using alternatives, though I understand that won't work for you
because of the additional CLOBBER.

Thanks for the feedback.

Ian


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