Parallel Programming Guide for HP-UX Systems

Glossary
column-major order
Glossary206
HP Fortran 90 can pass source files to the C
preprocessor (cpp) for preprocessing and
then send the output to the compiler.
column-major order The method of
storing Fortran 90 arrays in memory.
Column-major order requires the columns of
a two-dimensional array to be in contiguous
memory locations. For example, given the
array a(3,4), element a(1,1) would be
stored in the first location, a(2,1) in the
second, a(3,1) in the third, and so on. See
also row-major order..
core dump A core image of an executing
program that is deposited in a file after the
program aborted execution. The core dump
(also called a core file) may contain
information that is useful in debugging the
aborted program.
data dependence The relationship that
can obtain between the definition of data
and its use. The occurrence of a data
dependence in a loop can prevent the
optimizer from parallelizing it.
dde The command for invoking the HP
Distributed Debugging Environment,
the source-level debugger that is included
with HP Fortran 90.
debugger See HP Distributed Debugging
Environment.
division by zero The floating-point
exception that occurs whenever the system
attempts to divide a nonzero value by zero.
driver The component of the compiler that
retains control throughout the entire
compilation process.
dusty-deck programs Older,
pre-FORTRAN 77 programs. Dusty-deck
programs are so called because they were
presumably encoded and stored on punched
cards. Such programs are difficult to port
and optimize.
E-K
exception A condition occurring during the
execution of a program that may require
special handling to make further execution
meaningful. Some exceptions can be
trapped by the system and handled within
the program.
extension See filename extension and
language extension.
fast underflow A hardware feature for
handling underflow by substituting zero for
the operation that causes the underflow.
file descriptor An integer that is returned
by certain HP-UX system I/O routines and
then passed to others to provide access to a
file. A file descriptor is similar to Fortran’s
logical unit number. When the Fortran 90
intrinsic FNUM is given a logical unit number,
it returns a file descriptor.
filename extension A sequence of
characters that begins with a period (.) and
is added to a filename to indicate the
function or contents of the file. See also
language extension..
floating-point exception See exception.
front-end The component of the compiler
that parses source code and issues warning
and error messages. See also back-end..