floatingpoint.h

, floatingpoint

- IEEE floating point definitions

Synopsis

#include <floatingpoint.h>

Description

This file defines constants, types, and functions used to implement standard floating point according to ANSI/IEEE Std 754-1985. The functions are implemented in libc. The included header file <sys/ieeefp.h> defines certain types of interest to the kernel.

IEEE Rounding Modes

fp_direction_type

The type of the IEEE rounding direction mode. Note: the order of enumeration varies according to hardware.

fp_precision_type

The type of the IEEE rounding precision mode, which only applies on systems that support extended precision such as machines based on the Intel 80387 FPU or the 80486. SIGFPE handling:

sigfpe_code_type

The type of a SIGFPE code.

sigfpe_handler_type

The type of a user-definable SIGFPE exception handler called to handle a particular SIGFPE code.

SIGFPE_DEFAULT

A macro indicating the default SIGFPE exception handling, namely to perform the exception handling specified by the user, if any, and otherwise to dump core using abort(3C).

SIGFPE_IGNORE

A macro indicating an alternate SIGFPE exception handling, namely to ignore and continue execution.

SIGFPE_ABORT

A macro indicating an alternate SIGFPE exception handling, namely to abort with a core dump.

IEEE Exception Handling

N_IEEE_EXCEPTION

The number of distinct IEEE floating-point exceptions.

fp_exception_type

The type of the N_IEEE_EXCEPTION exceptions. Each exception is given a bit number.

fp_exception_field_type

The type intended to hold at least N_IEEE_EXCEPTION bits corresponding to the IEEE exceptions numbered by fp_exception_type. Thus fp_inexact corresponds to the least significant bit and fp_invalid to the fifth least significant bit. Note: some operations may set more than one exception.

IEEE Formats and Classification

single; extended; quadruple

Definitions of IEEE formats.

fp_class_type

An enumeration of the various classes of IEEE values and symbols.

IEEE Base Conversion

The functions described under floating_to_decimal(3C) and decimal_to_floating(3C) satisfy not only the IEEE Standard, but also the stricter requirements of correct rounding for all arguments.

DECIMAL_STRING_LENGTH

The length of a decimal_string.

decimal_string

The digit buffer in a decimal_record.

decimal_record

The canonical form for representing an unpacked decimal floating-point number.

decimal_form

The type used to specify fixed or floating binary to decimal conversion.

decimal_mode

A struct that contains specifications for conversion between binary and decimal.

decimal_string_form

An enumeration of possible valid character strings representing floating-point numbers, infinities, or NaNs.

Files

/usr/include/sys/ieeefp.h

See Also

abort(3C), decimal_to_floating(3C), econvert(3C), floating_to_decimal(3C), sigfpe(3C), string_to_decimal(3C), strtod(3C)