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RE: insv vs one-bit fields
- From: "Dave Korn" <dave dot korn at artimi dot com>
- To: "'DJ Delorie'" <dj at redhat dot com>, <gcc at gcc dot gnu dot org>
- Date: Sat, 21 Jan 2006 22:59:47 -0000
- Subject: RE: insv vs one-bit fields
DJ Delorie wrote:
> Why are one-bit bitfields not allowed? I'm trying to support a
> BSET/BCLR pair that *only* support single bit fields, for I/O ports,
> which are always volatile (and thus you have to use insv, as gcc won't
> do a "or #1,port5" if port5 is volatile).
;) Of course, you could always hack around combine to allow it to accept
volatiles in a tightly-circumscribed set of conditions that will allow gcc to
generate these OR instructions for you. I found that approach worked pretty
good for me; YMMV but I could always post a code sample...
cheers,
DaveK
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