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loatingpoint(3-BSD)
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).
SIGFPEIGNORE A macro indicating an alternate SIGFPE
exception handling, namely to ignore and
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loatingpoint(3-BSD)
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 excep-
tions. 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 signi-
ficant 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:
The functions described under
floatingtodecimal(3) and
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loatingpoint(3-BSD)
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 float-
ing binary to decimal conversion.
decimalmode A struct that contains specifications
for conversion between binary and
decimal.
decimalstringform An enumeration of possible valid charac-
ter 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.
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