copysign() returns x with the same sign as y. IEEE Std 754
requires copysign(x,NaN) = +x or -x.
Entry-Point Names
Generic
Function Data Type OpenVMS Tru64 UNIX
Name Required
copysign S_FLOAT math$copysign_s copysignf
T_FLOAT math$copysign_t copysign
X_FLOAT math$copysign_x copysignl
F_FLOAT math$copysign_f
G_FLOAT math$copysign_g