homepage

I'll take a look at this in an hour or two. I'll restrict the testing to the Xeon machine, as it is a zillion times quicker than the old SPARCs. 
What comes to my mind, is that perhaps 'copysign' is only defined in C99.
Solaris header files are pretty strict about what gets defined and not defined depending on the mode of compilation. The compiler option -std=c99 is not being passed yet the man page for copysign on my OpenSolaris laptop (yet another system) says:
drkirkby@laptop:~$ man copysign
Mathematical Library Functions copysign(3M)
NAME
 copysign, copysignf, copysignl - number manipulation func-
 tion
SYNOPSIS
 c99 [ flag... ] file... -lm [ library... ]
 #include <math.h>
 double copysign(double x, double y);
 float copysignf(float x, float y);
 long double copysignl(long double x, long double y);
DESCRIPTION
 These functions produce a value with the magnitude of x and
 the sign of y.