floatingpoint(3) (BSD Compatibility Package) floatingpoint(3)
NAME
floatingpoint - IEEE floating point definitions
SYNOPSIS
cc [ flag... ] file ... -lucb
#include <sys/ieeefp.h>
#include <fp.h>
DESCRIPTION
This file defines constants, types, variables, and functions used to
implement standard floating point according to ANSI/IEEE Std 754-
1985. The variables and functions are implemented in libucb.a. The
included file <sys/ieeefp.h> defines certain types of interest to the
kernel.
IEEE Rounding Modes:
fpdirectiontype The type of the IEEE rounding direction mode.
Note: the order of enumeration varies according
to hardware.
fpdirection The IEEE rounding direction mode currently in
force. This is a global variable that is
intended to reflect the hardware state, so it
should only be written indirectly through a
function that also sets the hardware state.
fpprecisiontype The type of the IEEE rounding precision mode,
which only applies on systems that support
extended precision.
fpprecision The IEEE rounding precision mode currently in
force. This is a global variable that is
intended to reflect the hardware state on systems
with extended precision, so it should only be
written indirectly.
SIGFPE handling:
sigfpecodetype The type of a SIGFPE code.
sigfpehandlertype The type of a user-definable SIGFPE exception
handler called to handle a particular SIGFPE
code.
SIGFPEDEFAULT A macro indicating the default SIGFPE exception
handling, namely to perform the exception
handling specified by calls to ieeehandler(3M),
if any, and otherwise to dump core using
abort(3).
8/91 Page 1
floatingpoint(3) (BSD Compatibility Package) floatingpoint(3)
SIGFPEIGNORE A macro indicating an alternate SIGFPE exception
handling, namely to ignore and continue
execution.
SIGFPEABORT A macro indicating an alternate SIGFPE exception
handling, namely to abort with a core dump.
IEEE Exception Handling:
NIEEEEXCEPTION The number of distinct IEEE floating-point
exceptions.
fpexceptiontype The type of the NIEEEEXCEPTION exceptions.
Each exception is given a bit number.
fpexceptionfieldtype
The type intended to hold at least
NIEEEEXCEPTION bits corresponding to the IEEE
exceptions numbered by fpexceptiontype. Thus
fpinexact corresponds to the least significant
bit and fpinvalid to the fifth least significant
bit. Note: some operations may set more than one
exception.
fpaccruedexceptions
The IEEE exceptions between the time this global
variable was last cleared, and the last time a
function was called to update the variable by
obtaining the hardware state.
ieeehandlers An array of user-specifiable signal handlers for
use by the standard SIGFPE handler for IEEE
arithmetic-related SIGFPE codes. Since IEEE
trapping modes correspond to hardware modes,
elements of this array should only be modified
with a function like ieeehandler(3M) that
performs the appropriate hardware mode update.
If no sigfpehandler has been declared for a
particular IEEE-related SIGFPE code, then the
related ieeehandlers will be invoked.
IEEE Formats and Classification:
single;extended Definitions of IEEE formats.
fpclasstype An enumeration of the various classes of IEEE
values and symbols.
IEEE Base Conversion:
Page 2 8/91
floatingpoint(3) (BSD Compatibility Package) floatingpoint(3)
The functions described under floatingtodecimal(3) and
decimaltofloating(3) not only satisfy the IEEE Standard, but
also the stricter requirements of correct rounding for all
arguments.
DECIMALSTRINGLENGTH
The length of a decimalstring.
decimalstring The digit buffer in a decimalrecord.
decimalrecord The canonical form for representing an unpacked
decimal floating-point number.
decimalform The type used to specify fixed or floating binary
to decimal conversion.
decimalmode A struct that contains specifications for
conversion between binary and decimal.
decimalstringform An enumeration of possible valid character
strings representing floating-point numbers,
infinities, or NaNs.
FILES
/usr/include/sys/ieeefp.h
/usr/include/fp.h
/usr/ucblib/libucb.a
SEE ALSO
decimaltofloating(3), econvert(3), floatingtodecimal(3),
ieeehandler(3M), sigfpe(3).
abort(3), strtod(3) in the Programmer's Reference Manual.
8/91 Page 3