Re: c/8131: Union of struct of union of struct bit field

Re: c/8131: Union of struct of union of struct bit field

[Philippe Trottier]

Hello,

	I filed this bug, but seems the definition says it is not a bug.  
Anyone here could tell me How to handle a case where 1 bit can decide  
the format of a 32 bit word ?

Bit 0 type of data

If bit 0 = 0
Bit 1-15 Real
Bit 16     Timing mark
Bit 17-31 Imaginary

If bit 0 = 1
Bit 1-5 Real
Bit 16-31 Raw data

Thank you 			
Philippe


On Thursday, October 3, 2002, at 01:50 PM, nathan@gcc.gnu.org wrote:

> Synopsis: Union of struct of union of struct bit field
>
> State-Changed-From-To: open->closed
> State-Changed-By: nathan
> State-Changed-When: Thu Oct  3 03:50:48 2002
> State-Changed-Why:
>     not a bug. This is how things are defined
>
> http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit- 
> trail&database=gcc&pr=8131
>

Re: c/8131: Union of struct of union of struct bit field

[Richard Henderson]

On Thu, Oct 03, 2002 at 02:07:49PM +0300, Philippe Trottier wrote:
> 	I filed this bug, but seems the definition says it is not a bug.  
> Anyone here could tell me How to handle a case where 1 bit can decide  
> the format of a 32 bit word ?

Push the one bit down into each structure.  If it's at 
the same place in each structure, then it doesn't matter
which one you access to examine it.


r~