As part of Haiku trac ticket 2696:http://dev.haiku-os.org/ticket/2696

These are present in the math.h header, but not yet implemented:
math.h:
	lgammal
	gamma_r
	gammaf_r

The following issues also need to be adressed in math.h:
	
1. Missing definition of float_t and double_t as described at opengroup.org.
2.  Missing declaration of FLT_EVAL_METHOD.
3.  Function "int isgreater(real-floating x, real-floating y);" is never defined or declared in the header.
4.  Function "int isgreaterequal(real-floating x, real-floating y);"  is never defined or declared in the header.
5.  Functions "int isless(real-floating x, real-floating y);,
    int islessequal(real-floating x, real-floating y);,
    int islessgreater(real-floating x, real-floating y);" are never defined or declared in  the header.
6.  Function "int isunordered(real-floating x, real-floating y);" is never defined or declared in the header.
7.  There is no definition of "MAXFLOAT" constant in the header.
8.  The following optional macros "FP_FAST_FMA, FP_FAST_FMAF, FP_FAST_FMAL" are not defined in the header.
9.  The following macros "FP_ILOGB0, FP_ILOGBNAN, MATH_ERRNO, MATH_ERREXCEPT, math_errhandling" are never defined in the header.

The functions need to provide the requirements as defined at:
http://www.opengroup.org/onlinepubs/9699919799/basedefs/math.h.html