[cxx-abi-dev] IEEE 754r half-precision fp mangling?

[PremAnand M Rao]

Rao, Premanand ("C and C++ Compilers, Nashua") wrote:
> Mark Mitchell wrote:
>> scott douglass wrote:
>>
>>> --- /tmp/abi-orig.html        2008-06-11 16:13:17.000000000 +0100
>>> +++ /tmp/abi.html     2008-06-11 16:22:57.000000000 +0100
>>> @@ -4239,6 +4239,10 @@
>>>                ::= e  # long double, __float80
>>>                ::= g  # __float128
>>>                ::= z  # ellipsis
>>> +              ::= De # IEEE 754r decimal floating point (size?)
>>> +              ::= Df # IEEE 754r decimal floating point (size?)
>>> +              ::= Dh # IEEE 754r half-precision floating point (16 bits)
>>> +              ::= Dr # IEEE 754r decimal floating point (size?)
>>>                ::= u <source-name> # vendor extended type
>> DFP folks: would one of you please fill in proper names for the DFP
>> mangling types?  And then I'll check in this change.
> 
> I think there is an error in the above, there should not be both a "De"
> and a "Dr".  I believe Michael suggested "Dr" for 128-bits decimal
> float, but Dennis and Daveed expressed a preference for "De" (instead of
> "Dr") to match the binary floating point mangling.  Unless Michael
> really wants "Dr" (instead of "De"), I believe the above table should be
> corrected with:
> 
> Df # IEEE 754r decimal floating point (32 bits)
> Dd # IEEE 754r decimal floating point (64 bits)
> De # IEEE 754r decimal floating point (128 bits)
> 
> and of course, Dh as Scott has correctly added.
> 
> PremAnand.

And I would also like to ask again the opinion of all on the list if 
"Dh" really is appropriate for the half-precision floating point types. 
  I ask, because I think the half-precision floating point type is a 
binary floating point type whereas the other "D[fde]" types are decimal 
floating point types.

PremAnand.