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Re: middle-end/9725: Invalid dependency determination


The following reply was made to PR middle-end/9725; it has been noted by GNATS.

From: "Jan Beulich" <JBeulich at novell dot com>
To: <bangerth at ticam dot utexas dot edu>
Cc: <velco at fadata dot bg>,<gcc-bugs at gcc dot gnu dot org>, <gcc-gnats at gcc dot gnu dot org>
Subject: Re: middle-end/9725: Invalid dependency determination
Date: Thu, 20 Feb 2003 09:01:39 +0100

 Which is almost as bad as the memcpy approach - the thing to be created
 that way (i.e. through a macro) can't possibly be an lvalue when
 supposed to access more than something contained within a single
 byte...
 I realized a supposedly legal (and working) approach anyway (though I
 continue to believe that the original bitfield approach is legal, too -
 just that it doesn't work with gcc...): Instead of having a union of
 aliased type and aliasing structure, add a flexible array of the aliased
 type to the end of the aliasing structure.
 
 >>> Wolfgang Bangerth <bangerth at ticam dot utexas dot edu> 19.02.03 18:14:43
 >>>
 
 > of not using this logic - how do I access sub-fields of a built-in
 type
 
 Go through a char* which can alias everything. This special case exists
 
 for this particular purpose: accessing single bytes in other types.
 
 W.
 
 -------------------------------------------------------------------------
 Wolfgang Bangerth             email:           
 bangerth at ticam dot utexas dot edu 
                               www:
 http://www.ticam.utexas.edu/~bangerth/ 
 
 


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