language

A feature of a programming language that has been added by a vendor

extension

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

condition that occurs when the result of a floating-point operation is greater

exception

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