representation of struct field offsets

[Mark Mitchell]

Richard Kenner wrote:
>> That doesn't explain why the bit value isn't normalized to be smaller 
>> than BITS_PER_UNIT; any whole bytes could be incorporated into the 
>> variably sized offset.
> 
> It can't be normalized to BITS_PER_UNIT, but to DECL_OFFSET_ALIGN since
> we are asserting that DECL_FIELD_OFFSET is aligned to DECL_OFFSET_ALIGN.

That doesn't make sense to me.  It seems to me that we can normalize it 
however we please; ultimately, all these representations just give us a 
way of computing the first bit of the field.  We presently choose to 
normalize to DECL_OFFSET_ALIGN, but we could just as well choose to 
normalize to BITS_PER_UNIT.  So long as we can compute the starting 
offset of the field, why does it matter what the normalization constant is?

-- 
Mark Mitchell
CodeSourcery
mark@codesourcery.com
(650) 331-3385 x713