1.5. Data Definitions for libm

This section defines global identifiers and their values that are associated with interfaces contained in libm. These definitions are organized into groups that correspond to system headers. This convention is used as a convenience for the reader, and does not imply the existence of these headers, or their content.

These definitions are intended to supplement those provided in the referenced underlying specifications.

This specification uses ISO/IEC 9899 C Language as the reference programming language, and data definitions are specified in ISO C format. The C language is used here as a convenient notation. Using a C language description of these data objects does not preclude their use by other programming languages.

1.5.1. fenv.h

#define FE_INEXACT	0x08
#define FE_UNDERFLOW	0x10
#define FE_OVERFLOW	0x20
#define FE_DIVBYZERO	0x40
#define FE_INVALID	0x80


#define FE_TONEAREST	0
#define FE_TOWARDZERO	0x1
#define FE_UPWARD	0x2
#define FE_DOWNWARD	0x3

typedef unsigned int fexcept_t;

typedef unsigned int fenv_t;
#define FE_DFL_ENV	((__const fenv_t *) -1)

1.5.2. math.h

#define fpclassify(x)	(sizeof (x) == sizeof (float) ? __fpclassifyf (x) : __fpclassify (x) )
#define signbit(x)	(sizeof (x) == sizeof (float)? __signbitf (x): __signbit (x))

#define FP_ILOGB0	-2147483647
#define FP_ILOGBNAN	2147483647