DIGITAL Fortran 90 Version 1.2 contains the following changes since Version 1.1:

• Support for REAL (KIND=16) (or REAL*16) X_float (extended precision) data type and its associated intrinsics (a DIGITAL Fortran extension). For more information see Section 1.12.
• Support for variable format expressions (VFEs), a DIGITAL Fortran extension (see Section 1.12).
• Support for OPTIONS statements, which allow you to specify command-line options in your source files. The OPTIONS statement is a DIGITAL Fortran extension.
• Intrinsic procedures FP_CLASS and IMAG (a DIGITAL Fortran extension).
• STATIC and AUTOMATIC declaration attributes and statements (a DIGITAL Fortran extension).
• The following f90 command options were added for Version 1.2:
  • The -convert fgx and -convert fdx options allow conversion of unformatted OpenVMS Alpha DIGITAL Fortran 77 data files. Similarly, the FDX and FGX keywords are recognized for the OPEN statement CONVERT keyword and the FORT_CONVERTn environment variable names.
    Specifying -convert fdx indicates the data contains::
    • Little endian integer format (INTEGER declarations of the appropriate size)
    • REAL*4 and COMPLEX*8 data in VAX F_float format
    • REAL*8 and COMPLEX*16 data in VAX D_float format
    • REAL*16 data in native X_float format
    
    Specifying -convert fgx indicates the data contains:
    • Little endian integer format (INTEGER declarations of the appropriate size)
    • REAL*4 and COMPLEX*8 data in VAX F_float format
    • REAL*8 and COMPLEX*16 data in VAX G_float format
    • REAL*16 data in native X_float format
  • The -double_size 128 option specifies that DOUBLE PRECISION declarations are implemented as extended precision REAL (KIND=16) data rather than double precision REAL (KIND=8) data.
  • The -real_size 128 and -r16 options allow a REAL declaration to be interpreted using the REAL (KIND=16) data type.
  • The -inline xxxxx options can be used to specify the type of inlining done independent of the -on option (optimization level) specified:
    • To prevent inlining of procedures (except statement functions), use -inline none or -inline manual .
      This is the type of inlining done with -o0 , -o1 , -o2 , or -o3 .
    • The -inline automatic option was replaced at Version 1.3 with -inline size and -inline speed (see Section 2.4), allowing more control over inlining.
    • To inline every call that can possibly be inlined while generating correct code, including: statement functions, procedures that Compaq Fortran thinks will improve run-time performance, and any other procedures that can possibly be inlined while generating correct code (certain recursive routines cannot be inlined), use -inline all . This option is meaningful only at optimization levels -o1 and higher.
  • The -gen_feedback option requests additional profiling information needed for feedback file use. You can use -gen_feedback with any optimization level up to -o3 (to avoid inlining procedures). If you omit a -on option, the -gen_feedback option changes the default optimization level to -o0 .
    A typical command-line sequence to create a feedback file ( profsample.feedback ) follows:

    % f90 -gen_feedback -o profsample -O3 profsample.f90 % pixie profsample % profsample.pixie % prof -pixie -feedback profsample.feedback profsample

  • The -feedback option now works with -cord or separately without -cord to specify a previously-created feedback file. For example:

    % f90 -feedback profsample.feedback -o profsample -O3 profsample.f90

    
    The feedback file provides the compiler with actual execution information, which the compiler can use to perform such optimizations as inlining function calls.
    The same optimization level ( -on option) must be specified for the f90 command with the -gen_feedback option and the f90 command with the -feedback name option.
    You can use the feedback file as input to the f90 compiler and cord , as follows:

    % f90 -cord -feedback profsample.feedback -o profsample -O3 profsample.f90

  • The -tune keyword option selects processor-specific instruction tuning for implementations of the Alpha architecture. Regardless of the setting of -tune keyword , the generated code will run correctly on all implementations of the Alpha architecture. Tuning for a specific implementation can improve run-time performance; it is also possible that code tuned for a specific target may run slower on another target.
    Choose one of the following:
    • To generate and schedule code that will execute well for both types of chips, use -tune generic . This provides generally efficient code for those cases where both types of chips are likely to be used. If you do not specify any -tune keyword option, -tune generic is used (default).
    • To generate and schedule code optimized for the type of chip in use on the system being used for compilation, use -tune host .
    • To generate and schedule code optimized for the 21064, 20164A, 21066, and 21068 implementations of the Alpha chip, use -tune ev4 .
    • To generate and schedule code optimized for the 21164 implementation of the Alpha chip, use -tune ev5 .
  • The -check noformat option disables the run-time message (number 61) associated with format mismatches. It also requests that the data item be formatted using the specified descriptor, unless the length of the item cannot accommodate the descriptor (for example, it is still an error to pass an INTEGER (KIND=2) item to an E edit descriptor). Using -check noformat allows such format mismatches as a REAL (KIND=4) item formatted with an I edit descriptor.
    If you omit the -vms option, the default is -check noformat .
    If you specify -vms and omit -check noformat , -check format is used.
  • The -check output_conversion option disables the run-time message (number 63) associated with format truncation. The data item is printed with asterisks. Error number 63 occurs when a number could not be output in the specified format field length without loss of significant digits (format truncation).
    If you omit the -vms option, the default is -check nooutput_conversion .
    If you specify -vms and omit -check nooutput_conversion , -check output_conversion is used.
  • The -vms option now sets defaults for -check output_conversion and -check format .

For more complete product information, see the Compaq Fortran documentation and the f90(1) reference (man) page.

2.6 New Features in Version 1.1

DIGITAL Fortran 90 Version 1.1 contains the following changes since Version 1.0:

• The following f90 command options were added for Version 1.1:
  • The -check bounds option generates additional code to detect out-of-bounds subscripts for array operations and character substring expressions at run-time. Use this option for debugging purposes.
  • The -idir option specifies an additional directory to be searched for files specified with an INCLUDE statement or module files. For Version 1.0, this option specified an additional directory searched for module files only.
  • The -warn argument_checking option issues a warning message about argument mismatches between the calling and the called procedure when both program units are compiled together.
• The fsplit command now accepts DIGITAL Fortran 90 free-form source files (see fsplit(1)). For example:

  % fsplit -f90 -free bigfile.f90

For more complete product information, see the Compaq Fortran documentation and the f90(1) reference (man) page.

The sections in this chapter:

• List known Compaq Fortran documentation corrections ( Section 3.1)
• Describe Compaq Fortran documentation and online information ( Section 3.2)
• Describe the main Compaq Parallel Software Environment documents ( Section 3.3)
• List other sources of information about Fortran 95/90 ( Section 3.4)

The Compaq Fortran Web page provides a wealth of information about Compaq Fortran products, including update (patch) kits:

http://www.compaq.com/fortran

3.1 Compaq Fortran Documentation Corrections

This section contains information that does not appear in the Compaq Fortran documentation. Included in each description is a notation of the first version to which it applies.

3.1.1 Compaq Fortran Installation Guide for Tru64 UNIX Systems

The following corrections apply to the installation guide, order number AA--PW82G--TE (January 2001 on the inside title page):

• No known corrections.

There are no known corrections to the Compaq Fortran User Manual for Tru64 UNIX and Linux Alpha Systems, order number AA--Q66TD--TE (December 1999 on the inside title page).

New features added for Version 5.4 are not shown in this manual (last updated for Version 5.3).

3.1.3 Compaq Fortran Language Reference Manual

There are no known corrections to the Compaq Fortran Language Reference Manual, order number AA--Q66SD--TK (September 1999 on the inside title page).

New features added for Version 5.4 are not shown in this multi-platform manual (last updated just before Version 5.3).

3.2 Compaq Fortran Documentation and Online Information

The Compaq Fortran documentation set includes the following:

• Compaq Fortran Installation Guide for Tru64 UNIX Systems (AA--PW82G--TE)
  Explains how to install Compaq Fortran (Compaq Fortran and Compaq Fortran 77) on a Compaq Tru64 UNIX Alpha system, including requirements.
  The installation guide is included with the Compaq Fortran (95/90) document kit, QA-MV2AA-GZ.5.n and the Compaq Fortran 77 kit, QA-MV2AB-GZ.5.n. It is also included in ASCII and PostScript® form on the Software Product Library CD-ROM (media CD-ROM) and is on the Online Documentation Library CD-ROM in HTML form.
• Compaq Fortran Language Reference Manual (AA--Q66SD--TK)
  Describes the Compaq Fortran source language for reference purposes, including the format and use of statements, intrinsic procedures, and other language elements. It also provides an overview of new Fortran 95/90 features (not available in FORTRAN-77).
  It identifies extensions to the Fortran 95 standard by blue-green color in the printed and HTML forms of this document.
  The Compaq Fortran Language Reference Manual is included with the Compaq Fortran (95/90) document kit, QA-MV2AA-GZ and is available on the Online Documentation Library CD-ROM in HTML form.
  The Compaq Fortran Language Reference Manual has been translated into Japanese and is available.
• Compaq Fortran User Manual for Tru64 UNIX and Linux Alpha Systems (AA--Q66TD--TE)
  Describes the Compaq Fortran program development and run-time environment on Compaq Tru64 UNIX Alpha systems. It describes compiling, linking, running, and debugging Compaq Fortran programs, performance guidelines, run-time I/O and error-handling support, data types, numeric data conversion, calling other procedures and library routines, and compatibility with Compaq Fortran 77. It provides information common to Compaq Fortran and the Compaq Parallel Software Environment as well as information about using directed parallel processing using OpenMP and Compaq Fortran directives.
  The printed version of this document is included with the Compaq Fortran (95/90) document kit, QA-MV2AA-GZ.5.n and is on the Online Documentation Library CD-ROM in HTML form.
• Read Before Installing or Using Compaq Fortran Version 5.n for Compaq Tru64 UNIX Systems (AV--PW83N--TE)
  This cover letter contains information about installing Compaq Fortran (Compaq Fortran and Compaq Fortran 77) that may not be included in the installation guide or in the release notes.
  This cover letter is included with the Compaq Fortran (95/90) document kit, QA-MV2AA-GZ.5.n, and the Compaq Fortran 77 kit, QA-MV2AB-GZ.5.n. It is also included on the Software Product Library CD-ROM (media CD-ROM) in ASCII and PostScript form.

The Compaq Fortran Software Product Description (SPD) is provided as a file on the Software Product Library CD-ROM (media CD-ROM).

The following Compaq Fortran online information is available (once installed on the system):

• Compaq Fortran online reference pages (man pages)
  Describe the Compaq Fortran software components, including f90(1), fpr(1), fsplit(1), intro(3f), numerous Fortran library routines listed in intro(3f), and numerous parallel High Performance Fortran library routines listed in intro(3hpf).
• Compaq Fortran online release notes
  Provide more information on this version of Compaq Fortran, including known problems and a summary of the Compaq Fortran run-time error messages. These release notes are also provided on the Software Product Library CD-ROM (media CD-ROM).
  Once installed, the online release notes are located in:

  /usr/lib/cmplrs/fort90/relnotes90

  
  To view this file, use the more command (or view or similar command) on a system where Compaq Fortran is installed:

  % more /usr/lib/cmplrs/fort90/relnotes90

  
  To initiate a search within more , type a slash (/) followed by the appropriate topic. For information about using the more command, see more(1).

• Compaq Fortran online help file
  This ASCII file provides online access to Compaq Fortran information, which includes error message descriptions, a summary of the language elements (statements, intrinsic functions, and so on), a glossary, and other information. The Compaq Fortran help file is located in:

  /usr/lib/cmplrs/fort90/decfortran90.hlp

  
  Use the more command or the view command to access the information available in these ASCII files. These help files are large and are not usually printed on a printer or read sequentially.

The Compaq Fortran Installation Guide for Tru64 UNIX Systems, these online release notes, the "read first" cover letter, and the SPD are available on the Compaq Tru64 UNIX Software Product Library CD-ROM (media CD-ROM) in ASCII and PostScript format.

All Compaq Fortran documents except the cover letter and SPD are available on the Compaq Tru64 UNIX Online Documentation Library CD-ROM in HTML format.

3.3 Compaq HPF and Parallel Software Environment Documentation

The Compaq Parallel Software Environment product is no longer supported. The DIGITAL High Performance Fortran 90 HPF and PSE Manual (in the Compaq Parallel Software Environment documentation kit, QA-2ATAA-GZ), however, still contains important HPF documentation in Chapters 1-8.

The DIGITAL High Performance Fortran 90 HPF and PSE Manual explains both the (now retired) Parallel Software Environment (PSE) and the (still current) High Performance Fortran (HPF) programming language. It contains a tutorial describing how to write programs using the HPF extensions to Compaq Fortran.

3.4 Other Sources of Information About Fortran 95/90

This section lists sources of information about Fortran 95/90 other than the Compaq Fortran documentation.

The following publication is the copywritten standard for Fortran 90 and 95:

• American National Standard Programming Language Fortran 90, ANSI X3.198-1991, and International Standards Organization Programming Language standard ISO/IEC 1539:1991. (Simply referred to in documentation as the "Fortran 90 Standard".)
• American National Standard Programming Language Fortran 95, X3J3/96-007, and International Standards Organization Programming Language standard ISO/IEC 1539-1:1996. (Simply referred to in documentation as the "Fortran 95 Standard".)

Tutorial information about the Fortran 95/90 language is available in commercially published documents at major book stores or from their publishers. Compaq Fortran documentation does not usually provide such tutorial information. The following commercially published documents (listed in alphabetical order by title) in English provide reference or tutorial information about Fortran 90:

• Fortran 90 Explained by M. Metcalf and J. Reid, Published by Oxford University Press, ISBN 0-19-853772-7.
• Fortran 90/95 Explained by M. Metcalf and J. Reid, Published by Oxford University Press, ISBN 0-19-851888-9.
• Fortran 90/95 for Scientists and Engineers by S. Chapman, Published by WCB McGraw-Hill, ISBN 0-07-011938-4.
• Fortran 90 Handbook by J. Adams, W. Brainerd, J. Martin, B. Smith, and J. Wagener, Published by Intertext Publications (McGraw-Hill), ISBN 0-07-000406-4.
• Fortran 90 Programming by T. Ellis, I. Philips, and T. Lahey, Published by Addison/Wesley, ISBN 0201-54446-6.
• Introduction to Fortran 90/95 by S. Chapman, Published by WCB McGraw-Hill, ISBN 0-07-011969-4.
• Programmer's Guide to Fortran 90, Second Edition by W. Brainerd, C. Goldberg, and J. Adams, Published by Unicomp, ISBN 0-07-000248-7.

For information on parallel programming using OpenMP, see the following:

• Parallel Programming in OpenMP by Rohit Chandra, Ramesh Menon, Leo Dagum, David Kohr, Dror Maydan, and Jeff MCDonald, Published by Morgan Kauffman, ISBN 1-55860-671-8.

For information on High Performance Fortran (HPF), see the following:

• High Performance Fortran Language Specification, Version 2.0. This specifications is available online on the World Wide Web as follows:

  http://www.crpc.rice.edu/HPFF/home.html

Compaq provides this list of Fortran 90/95 documents (books) for the sole purpose of assisting customers who want to learn more about the Fortran 90/95 language. This list of documents does not comment---either positively or negatively---on any of the documents listed or any not yet listed. Any omissions are not intentional. Publications that become available after the revision of a Compaq Fortran document will be added at the next revision.

Contents