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Re: Feature request: ability to describe x86 register halves as contraints.
- To: law at cygnus dot com
- Subject: Re: Feature request: ability to describe x86 register halves as contraints.
- From: Joern Rennecke <amylaar at cygnus dot co dot uk>
- Date: Tue, 30 Jun 1998 17:55:48 +0100 (BST)
- Cc: ak at muc dot de, egcs at cygnus dot com
> > Is it possible to add such an extension to the constraints language?
> > Hopefully only minimal changes should be needed for this.
> First there'd have to be a way to describe hi/lo halves of registers
> in RTL. I'm not aware of any such mechanism.
I think we should change SUBREG to count addressable units instead of
'words'. This would also fix some brokenness when there are
varying register sizes (E.g. floating point wider than integer...)