[PATCH] D15120: Add support for __float128 type to be used by targets that support it

John McCall via cfe-commits cfe-commits at lists.llvm.org
Tue Jan 26 12:02:01 PST 2016

rjmccall added a comment.

In http://reviews.llvm.org/D15120#336282, @nemanjai wrote:

> Addressed review comments.
>  The key differences are:
> - No assignments or operations between entities of long double and __float128 allowed if the two types have a different representation
> - Each type has a distinct rank
>   This isn't the same behaviour as GCC currently has. For example, GCC allows assignments between the two types on PowerPC. The conversion is achieved through a library routine. However, there is no compelling reason at this point to allow such behaviour and this work is deferred until such a need arises.

As I understand it, PPC's long-double (~103 bits of precision) is still strictly less precise than float128_t (113 bits of precision), so it ought to be have lower rank.  Is there actually a supported platform where this is not true?  If not, we should just add this as another type with higher rank.



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