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



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.