How to Use This Document

This document is for anyone who wants to work with the XL Fortran compiler, who is familiar with the Linux operating system, and who has some previous Fortran programming experience.

This document can help you understand what the features of the compiler are, especially the options, and how to use them for effective software development.

This document is not the place to find help on:

Installation,
which is covered in the IBM XL Fortran Advanced Edition V9.1 for Linux Installation Guide.
Writing Fortran programs,
which is covered in the XL Fortran Language Reference.

The first part of this document is organized according to the steps necessary to compile, link, and run a program, followed by information on particular features of the XL Fortran compiler and the programs it produces.

The second part discusses more general software-development topics.

Depending on your level of experience and what you want to do, you may need to start reading at a particular point or read in a particular sequence. If you want to:

Set up the compiler for yourself or someone else,
read Where to Find Installation Instructions.
Create customized compiler defaults,
read Customizing the Configuration File.
Understand what all the compiler options are for and how they relate to each other,
browse through Summary of the XL Fortran Compiler Options.
Look up a particular option by name,
scan alphabetically through Detailed Descriptions of the XL Fortran Compiler Options.
Port a program to XL Fortran,
read Options for Compatibility to see what options you may need; then read Porting Programs to XL Fortran for other porting information.

How to Read the Syntax Diagrams and Statements

This document uses notation often referred to as "railroad tracks" to illustrate syntax for Fortran statements and Linux commands. Syntax for compiler options is illustrated through statements using notation often referred to as "braces and brackets".

Fortran keywords are shown in uppercase: for example, OPEN, COMMON, and END. You must spell them exactly as they are shown, although they are not case-sensitive.

Variable names and user-specified names appear in lowercase italics; for example, array_element_name.

If a variable or user-specified name ends in _list, it means that you can provide a list of terms that are separated by commas.

You must enter punctuation marks, parentheses, arithmetic operators, and other special characters as part of the syntax.

Syntax Diagrams

Example of a Syntax Diagram

                                         .-,-.  .-,-------------.
                                         V   |  V               |
>>-EXAMPLE--char_constant--+-a-+--+---+----e-+----+-----------+-+-><
                           '-b-'  +-c-+           '-name_list-'
                                  '-d-'
 
 

Interpret the diagram as follows:

Syntax Statements

Syntax statements are read from left to right:

Example of a Syntax Statement

EXAMPLE char_constant {a|b}[c|d]e[,e]... name_list{name_list}...

The following list explains the syntax statement:

Note:
The same example is used in both the syntax-statement and syntax-diagram representations.

Notes on the Examples in This Document

Notes on the Path Names in This Document

The path names shown in this document assume the default installation path for the XL Fortran compiler. By default, XL Fortran will be installed in the following directory on the selected disk:

/opt/ibmcmp/xlf/9.1

You can select a different destination (relocation-path) for the compiler. If you choose a different path, the compiler will be installed in the following directory:

relocation-path/opt/ibmcmp/xlf/9.1

Notes on the Terminology in This Document

Some of the terminology in this document is shortened, as follows:

Typographical Conventions

This document uses the following methods to differentiate text:

IBM Copyright 2003