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Re: [C++0x] contiguous bitfields race implementation

On 05/26/2011 01:39 PM, Aldy Hernandez wrote:
On 05/26/11 12:24, Jason Merrill wrote: 
struct A
{
  int i: 4;
  int j: 28;
};

we won't use SImode to access A::j because we're setting maxbits to 28. 

No, maxbits is actually 32, because we include padding. So it's correct
in this case.

What padding? bitregion_end-bitregion_start+1 will be 32, but in get_best_mode I see

+ maxbits = bitregion_end - bitpos + 1;

which is 28. No?

Incidentally, I would expect _end to be one past the end rather than the index of the last element, but perhaps I just expect that because C++ iterators work that way.

Jason

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