egcs and bitfields

David A. Greene greened@eecs.umich.edu
Thu Mar 11 14:33:00 GMT 1999


I sent this question to the list a few days ago but got
no response.  Can someone please help me out?

I'm trying to figure out the alignment rules that egcs 
uses for bitfields under Linux 2.0.x.  It seems that egcs 
does not follow the System V ABI stardard.  Specifically, 
the part about not allowing bitfields to cross the 
alignment boundaries of their base types (i.e. int c:17 
should not cross a 32-bit boundary, but egcs allows it).  
Also, bitfields declared "int" are treated as signed by 
egcs while the System V ABI indicates they are unsigned.

What ABI is egcs conforming to?  I need some detailed 
information as we need to interface to code compiled by
egcs.

Thanks!

                                -Dave


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