HP-UX Floating-Point Guide

Glossary 229
Glossary
standard is Binary floating-point
arithmetic for microprocessor
systems (IEC 559:1989).
ill-conditioned Of or pertaining
to a computation in which small
changes to the input or to the
intermediate results cause
relatively large changes in the
final output.
inexact result condition The
exception condition that occurs
when a floating-point operation
produces a result that cannot be
represented exactly in the specified
floating-point format. Because
most floating-point operations
produce inexact results most of the
time, the inexact result condition
is not usually considered to be an
error. See also rounding.
infinity A floating-point value
that is represented by a sign bit, a
fraction that is all zeros, and an
exponent that is all ones. An
infinity has a magnitude greater
than any normalized value.
instruction cache aliasing The
form of cache aliasing that occurs
when two routines reside at
addresses that have the same low-
order bits but different high-order
bits. See also cache aliases, data
cache aliasing.
invalid operation
condition The exception
condition that occurs whenever
the system attempts to perform an
operation that has no numerically
meaningful interpretation (for
example, 0.0/0.0).
least significant word In
double-precision and quad-
precision floating-point
formats, the 32-bit word in the
representation that contains the
last portion of the fraction. See also
most significant word.
library A collection of commonly
used routines, pre-compiled in
object format and ready to be
linked to an application.
mask bits See exception trap
enable bits.
math library A library that
contains routines that perform
higher-level mathematical
operations. On HP 9000 systems, C
math library functions are located
in the libm math library; Fortran
and Pascal intrinsic functions are
located in the libcl library; and
Basic Linear Algebra Subroutine
(BLAS) library routines are located
in the BLAS library (libblas).