HP Fortran Programmer Guide (766160-001, March 2014)

language
extension
A feature of a programming language that has been added by a vendor
and is not defined in (or is in violation of) the language standard. The
ONstatement is an HP language extension to the Fortran 90 Standard. See
also filename extension..
libU77 routines Routines in the BSD 3f library (libU77.a) that provide a Fortran 90
interface to selected system calls in libc.a. The libU77.alibrary is part
of HP Fortran 90 and is accessed with the +U77option.
migrating In this document, migrating refers to the processing of moving a program
written for HP FORTRAN 77 to HP Fortran 90. See also porting..
memory fault See segmentation violation.
millicode routines Millicode versions of frequently called intrinsics, having very low call
overhead and little error-handling. One of the optimizations performed by
HP Fortran 90 is to replace calls to eligible intrinsics with millicode versions.
.mod file A file that is created and read by the compiler when processing Fortran
90 source files that define or use modules.
module A type of Fortran 90 program unit that is used for sharing data. Modules
can also be used to contain subprograms.
NaN Not-a-Number, the condition that results from a floating-point operation
that has no mathematical meaning, such as infinity divided by infinity. The
ONstatement can be used to trap operations that result in NaN.
null The null character ('\0') that is used in C programs to terminate strings.
O-Q
one-trip DO loop A DOloop that, if reached, executes for at least one iteration. Programs
written for some implementations of FORTRAN 66 rely on one-trip DOloops.
optimization Code transformations made by the compiler to improve program
performance.
overflow an
exception
condition that occurs when the result of a floating-point operation is greater
than the largest normalized number. See also integer overflow.
parallel execution Program execution on multiple processors at the same time. One of the
optimizations performed by the compiler is to transform eligible program
loops for parallel execution.
parallelization An optimization that transforms eligible program loops for parallel execution
on a multiprocessor machine.
PIC See position-independent code.
porting In this document, porting refers to the process of moving a program that
was coded for another vendor’s Fortran to HP Fortran 90. See also See
also migrating..
position-independent code
Object code that contains no absolute addresses. Position-independent
code (PIC) has linkage tables that contain pointers to code and data. This
table is filled in by the loader at runtime. Object code that consists of PIC
can be used to create shared libraries.
precision The number of digits to which floating-point numbers are represented.
Double-precision numbers can have greater precision than single-precision
numbers.
156 Glossary