This is the mail archive of the libstdc++@gcc.gnu.org mailing list for the libstdc++ project.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [PATCH] mips64-linux-gnu abi_check issues

Benjamin Kosnik writes:
> All the machinery is right, but I have one more question: why are
> exported OBJECT sizes the same between mips/mips64?
> 
> Say for _ZTVSd, 
> 
> powerpc:
> OBJECT:60:_ZTVSd@@GLIBCXX_3.4
> 
> powerpc64
> OBJECT:120:_ZTVSd@@GLIBCXX_3.4
> 
> I would expect to see this for mips/mips64 too. Why is this not the
> case?

It's most likely due the default ABI being N32 with MIPS64.  N32 has access to
the whole 64 bits in registers (e.g. via long long) but uses same type sizes
as O32, i.e. ILP32.  With N64 (the less-backward-compatible MIPS64 ABI) I am
sure we had more differences.

Do you want me to actually go and look at the generate assembly for the above
object or this suffices?

Adam
Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]