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Re: More /u conflicts
- To: Richard Kenner <kenner at vlsi1 dot ultra dot nyu dot edu>
- Subject: Re: More /u conflicts
- From: Richard Henderson <rth at redhat dot com>
- Date: Wed, 14 Feb 2001 16:12:03 -0800
- Cc: gcc at gcc dot gnu dot org
- References: <10102142348.AA26939@vlsi1.ultra.nyu.edu>
On Wed, Feb 14, 2001 at 06:48:11PM -0500, Richard Kenner wrote:
> *Now* we have two stores into a /u value, the second one being originally
> inserted by regmove.
Regmove attempts to check for the /u bit and not perform
such invalid optimizations. Apparently it missed a case.
> I think the only way to deal with this is to view two /u references as
> always conflicting.
I think you've just uncovered a bug in regmove. Even if
the pseudo _did_ get a hard register, we have invalid rtl
coming out of regmove: /u on a reg means it is assigned
not more than once.
> Note also that this does not show up without -g, meaning that register
> allocation or something depends on -g and that's very bad news!
Eek!
r~