About This Guide

This guide provides information on implementing FORTRAN 77 programs using the MIPSpro Fortran 77 compiler, version 7.4, which runs on the IRIX operating system, version 6.5 and later. This implementation of FORTRAN 77 contains full American National Standards Institute (ANSI) Programming Language Fortran (X3.9-1978) (in June, 1997, ANSI no longer supported this standard). Extensions provide full VMS Fortran compatibility to the extent possible without the VMS operating system or VAX data representation. This implementation of FORTRAN 77 also contains extensions that provide partial compatibility with programs written in SVS Fortran. This book also describes the Auto-Parallelizing Option (APO) which is an optional software product available for purchase.

The MIPSpro Fortran 77 compiler supports the -n32 and -n64 ABI (Application Binary Interface). The Fortran 77 compiler supports only the -o32 ABI.

Related Compiler Publications

This manual is one of a set of manuals that describes the compiler. The complete set of manuals is as follows:

  • The MIPSpro Fortran 77 Language Reference Manual provides a description of the FORTRAN 77 language as implemented on SGI systems.

  • The MIPSpro N32/64 Compiling and Performance Tuning Guide provides information about improving program performance by using the optimization facilities of the compiler system, the dump utilities, archiver, debugger, and the tools used to maintain Fortran programs.

  • The MIPSpro 64-Bit Porting and Transition Guide provides an overview of the 64-bit compiler system and language implementation differences, porting source code to the 64-bit system, compilation and run-time issues.

  • The MIPSpro Fortran 90 Commands and Directives Reference Manual provides information about the Fortran 90 and 95 compiler.

  • The f77(1), abi(5), lno(5), o32(5), opt(5), and pe_environ(5) man pages

Compiler Messages

You can obtain compiler message explanations by using the online explain(1) command.

Compiler Man Pages

In addition to printed and online prose documentation, several online man pages describe aspects of the compiler. Man pages exist for the library routines, the intrinsic procedures, and several programming environment tools.

You can print copies of online man pages by using the pipe symbol with the man(1), col(1), and lpr(1) commands. In the following example, these commands are used to print a copy of the explain(1) man page:

% man explain | col -b | lpr

Each man page includes a general description of one or more commands, routines, system calls, or other topics, and provides details of their usage (command syntax, routine parameters, system call arguments, and so on). If more than one topic appears on a page, the entry in the printed manual is alphabetized under its primary name; online, secondary entry names are linked to these primary names. For example, egrep is a secondary entry on the page with a primary entry name of grep. To access egrep online, you can type man grep or man egrep. Both commands display the grep man page to your terminal.

Obtaining Publications

Silicon Graphics maintains publications information at the following web site:


This library contains information that allows you to browse documents online, order documents, and send feedback to Silicon Graphics.

To order a printed Silicon Graphics document, call 1-800-627-9307.

Customers outside of the United States and Canada should contact their local service organization for ordering and documentation information.


The following conventions are used throughout this document:




This fixed-space font denotes literal items such as commands, files, routines, path names, signals, messages, and programming language structures.


Italic typeface denotes variable entries and words or concepts being defined.

user input 

This bold, fixed-space font denotes literal items that the user enters in interactive sessions. (Output is shown in nonbold, fixed-space font.)

[ ] 

Brackets enclose optional portions of a command or directive line.


Ellipses indicate that a preceding element can be repeated.

Reader Comments

If you have comments about the technical accuracy, content, or organization of this publication, contact SGI. Be sure to include the title and document number of the publication with your comments. (Online, the document number is located in the front matter of the publication. In printed publications, the document number is located at the bottom of each page.)

You can contact SGI in any of the following ways:

  • Send e-mail to the following address:

    [email protected]

  • Use the Feedback option on the Technical Publications Library Web page:


  • Contact your customer service representative and ask that an incident be filed in the SGI incident tracking system.

  • Send mail to the following address:

    Technical Publications
    1600 Amphitheatre Parkway, M/S 535
    Mountain View, California 94043-1351

  • Send a fax to the attention of “Technical Publications” at +1 650 932 0801.

SGI values your comments and will respond to them promptly.