Hans-Peter Nilsson - Re: [RFC] What should be the semantics of a zero-bit bit-field withpragm (original) (raw)

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• From: Hans-Peter Nilsson
• To: Steven Bosscher
• Cc: gcc at gcc dot gnu dot org, jason at redhat dot com, mark at codesourcery dot com, marcus at jet dot franken dot de, joseph at codesourcery dot com
• Date: Wed, 9 Nov 2005 23:55:13 -0500 (EST)
• Subject: Re: [RFC] What should be the semantics of a zero-bit bit-field withpragma pack?
• References: <200511072034.18179.stevenb@suse.de>

On Mon, 7 Nov 2005, Steven Bosscher wrote:

1. when we see :0 align to the next unit, which seems to be the behavior of GCC pre-3.4.

If by "unit" you mean "size of type for the :0 field" for targets with PCC_BITFIELD_TYPE_MATTERS==1, and "byte" for non-PCC_BITFIELD_TYPE_MATTERS targets, fine with me. Actually, only the latter is of interest to me at present. :-)

(Else that'd imply a change of the ABI for CRIS which is "packed by default" so :0 causes padding to the next byte.)

brgds, H-P

• References:
  • [RFC] What should be the semantics of a zero-bit bit-field with pragma pack?
    * From: Steven Bosscher