[PATCH v2] Replace copysign (0,-1) with -0.0 in initializer

[Joseph Myers]

On Tue, 17 Dec 2024, Maciej W. Rozycki wrote:

>  I was not able to track down a definitive standards reference requiring 
> IEEE 754 compiler implementations to respect the sign of zero in literals, 
> would you or anyone else be able to point me at one?

C23 Annex F binds unary '-' to the 'negate' operation (which is defined in 
IEEE 754 as a quiet-computational operation that affects only the sign 
bit, even for NaNs), and specifies that literal conversions (bound to 
convertFromDecimalCharacter, though the detailed syntax is given in the C 
standard) are correctly rounded up to at least CR_DECIMAL_DIG digits.

-- 
Joseph S. Myers
josmyers@redhat.com