8.25 math.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/math.h.html

Gnulib module: math

Portability problems fixed by Gnulib:

• The conversion from int to long double in incorrect on some platforms: glibc 2.7 on Linux/SPARC64.
• The macro NAN is not defined on some platforms: OpenBSD 4.0, AIX 5.1, IRIX 6.5.
• The macro NAN is not exposed outside of C99 compilation on some platforms: glibc.
• The macros NAN and HUGE_VAL expand to a function address rather than a floating point constant on some platforms: Solaris 10.
• The macros HUGE_VALF and HUGE_VALL are not defined on some platforms: glibc/HPPA, glibc/SPARC, AIX 5.1, IRIX 6.5, Solaris 9, MSVC 9.
• The macros FP_ILOGB0 and FP_ILOGBNAN are not defined on some platforms: NetBSD 5.1, AIX 5.1, IRIX 6.5, Solaris 9, MSVC 9.
• The macros FP_ILOGB0 and FP_ILOGBNAN have wrong values on some platforms: Haiku 2017.
• The macros NAN, HUGE_VALL, and INFINITY are not defined on some platforms: OpenVMS.

Portability problems not fixed by Gnulib:

• NAN is not a compile time constant with some compilers: OpenVMS.
• The macro or variable math_errhandling is not defined on some platforms: glibc 2.11, OpenBSD 4.9, NetBSD 5.1, UP-UX 11, IRIX 6.5, Cygwin 1.7.9, mingw, MSVC 9.