[PATCH][risc-v] libstdc++: Preserve signbit of nan when converting float to double [PR113578]

[Jeff Law]

On 5/7/24 7:49 AM, Jonathan Wakely wrote:
> Do we want this change for RISC-V, to fix PR113578?
> 
> I haven't tested it on RISC-V, only on x86_64-linux (where it doesn't do
> anything).
> 
> -- >8 --
> 
> libstdc++-v3/ChangeLog:
> 
> 	PR libstdc++/113578
> 	* include/std/ostream (operator<<(basic_ostream&, float)):
> 	Restore signbit after converting to double.
No strong opinion.     One could argue that the existence of a 
conditional like that inherently implies the generic code is dependent 
on specific processor behavior which probably is unwise.  But again, no 
strong opinion.

jeff