Lahey Fujitsu Fortran 95 for Linux (32-bit)

Lahey/Fujitsu Fortran 95 v6.2 for Linux
Full Fortran 77, 90, and 95

Lahey Inc have combined our 35 years of producing award-winning Fortran language systems with Fujitsu’s compiler expertise and high-performance code generator to deliver the most-productive, best-supported Fortran 95 language system for the PC.

Whether you write new Fortran programs or downsize existing applications, you need speed, dependability, and great tech support. You need Lahey/Fujitsu Fortran 95!

LF95 v6.2 Delivers!
Important features include …

  • Automatic Parallelization
  • Pentium 4 and Xeon optimizations with SSE2 instructions
  • OpenMP v2.0 Support
  • Prefetch optimizations for Pentium III and Athlon
  • Unsurpassed global compile-time and runtime diagnostics
  • Allocate arrays up to 2 GB
  • External file size 2**64 bytes
  • New Wisk, Winteracter Starter Kit
  • Thread-safe BLAS and LAPACK v3.0 (includes SSE2 version)
  • Thread-safe SSL2 math library (includes SSE2 version)
  • Automake, automatic make utility
  • ALLOCATABLE attributes on array components
  • Character variable length limit: 2,147,483,647
  • MPI compatible with MPICH source included
  • FDB debugger
  • Compatible with TotalView parallel debugger

“Our application is based on the finite-difference time-domain method. Using the auto-paralization feature of LF95 Pro v6.2, we reduced the execution time by approximately 50%.”

Masafumi Fujii
Dept. of Electrical , Electronic and System Engineering
Toyama University, Yoyama, Japan

LF95 v6.2 is available in two configurations, Express and PRO:

LF95 Express includes the powerful Lahey/Fujitsu Fortran 95 optimizing compiler, command line debugger, link-compatibility with g77 and egcs, online documentation, and free e-mail support.

LF95 PRO adds auto-parallelization, OpenMP compatibility, the Winteracter Starter Kit, WiSK, for creating Windows GUIs and displaying graphics, thread-safe BLAS and LAPACK, Polyhedron’s Automake utility, the Fujitsu SSL2 math library (thread-safe for parallel applications).

LF95 Performance

LF95 6.2 features P4 optimizations with SSE2 instructions. We tested v6.2 optimizations on a 1.8GHz P4 with 512 MB of PC2100 RAM, running SuSE 8.1, using Polyhedron’s ( Fortran benchmarks. Specifying the new switches –tp4, –sse2, –zfm, –o2, and -x, the 90 benchmarks ran an average of 12.4% faster and the 77 benchmarks 7.9% faster than they did when built with LF95 Linux v6.1. Try LF95 v6.2 on your code today!

LF95 Optimizations

Basic Optimization

  • Constant folding
  • Common subexpression elimination
  • Copy propagation
  • Strength Reduction
  • Algebraic simplifications
  • Dead code elimination
  • Peephole optimization
  • Loop invariant code motion
  • Transform array element to simple variable
  • Local Instruction scheduling
  • Address calculation optimization

Program Reconstruction Optimizations

  • Loop unrolling
  • Loop interchange

Procedure Optimization

  • Inlining mathematical functions
  • Stack optimization


  • P4 with SSE2 instructions
  • Prefetch for Pentium III and Athlon processors
  • I486/Pentium/Pentium PRO instruction selection
  • Using fast input/output libraries

Link Fujitsu C, g77, and egcs object files
LF95 supports static linking with Fujitsu C, g77, or egcs. Combine your Fortran and C/C++ code into one executable. For the routines you don’t want to develop yourself, you can also link with C/C++ routines from commercially available libraries.

Legacy Fortran Support
LF95 extends its language support in other directions adding many legacy Fortran features, including VAX structures and the various UNIX service routines. These features further facilitate your move to cost/performance efficiency on the PC platform:

  • Unlimited number of continuation lines in free or fixed source form
  • DO UNTIL statement
  • FIND statement
  • STRUCTURE and END STRUCTURE statements
  • UNION and END UNION statements
  • MAP and END MAP statements
  • RECORD statement
  • Non-standard POINTER statement
  • AUTOMATIC statement
  • STATIC statement
  • VALUE statement
  • BYTE statement
  • Hollerith constants
  • Alternative forms of binary, octal, and hexadecimal constants
  • Binary, octal, or hexadecimal constants in a DATA, declaration statement
  • Period structure component separator
  • Namelist input/output on internal file
  • TOTALREC specifier
  • STATUS = ‘SHR’
  • Gw, $, , and R edit descriptors
  • LOC intrinsic function

ANSI/ISO-Compliant Fortran 95
LF95 is a complete implementation of the ANSI/ISO Fortran 95 standard. Fortran 95 offers some small but important improvements over Fortran 90, including the ability to create your own elemental procedures, default initialization for structure components, the NULL intrinsic for initializing pointers, the FORALL construct, and a standard CPU_TIME intrinsic procedure.

Free Technical Support
LF95 Linux Express includes e-mail technical support at no extra charge.

Automatic Parallelization
The LF95 compiler automatically parallelizes DO loops and array operations without you having to make modifications to the program. This makes it easy to migrate source programs to other platforms (as long as the program conforms with the Fortran Standard). The effect is to save elapsed execution time by using two or more CPUs simultaneously. For instance, if a DO loop can be executed in parallel by dividing it in half, then, theoretically, the execution time of this DO loop may be cut in half. In practice, improving performance requires some care and some work on the part of the programmer. During compilation, the auto-parallel function will return information regarding which processes were (and which were not) parallelized and why. While certain loops can be analyzed sufficiently to be parallelized by the compiler without input from the programmer, many loops have data dependencies that prevent automatic parallelization because of the potential for incorrect results. For that reason, LF95 PRO also includes optimization control lines (OCLs) that provide information necessary for the compiler to parallelize these otherwise unparallelizable loops. The OCLs are Fortran comments in a particular format, for example:


Note that programs with OCLs are standard-conforming and can be compiled with other compilers that do not support OCLs.

Four compiler switches control automatic parallelization: –parallel, –threads, –threadstack, and –ocl. Details of automatic parallelization (loop slicing, interchange, distribution, fusion, and reduction, as well as OCL syntax and specifiers) are documented in the LF95 User’s Guide and at

OpenMP v2.0 Compatibility
OpenMP specifies a set of compiler directives, library routines, and environment variables for shared-memory parallelism in Fortran and C/C++ programs. LF95 Linux PRO v6.2 supports the OpenMP v2.0 specification for Fortran. Like automatic parallelization, OpenMP directives are used to parallelize a program that runs on a computer with more than one processor. With OpenMP you have more control over how code is parallelized, but also more coding to do.

The LF95 Linux PRO v6.2 CD includes the OpenMP v2.0 Fortran specification in PDF. You can also view the specification at You can learn more about OpenMP at

Winteracter Starter Kit
Use the Winteracter Starter Kit – WiSK – for creating true X/Windows programs with Fortran. WiSK is a subset of the X/Winteracter Library created by Interactive Software Services, Ltd. (X/Winteracter is available from Lahey.) X/Winteracter is a Fortran 95-callable, 32-bit, X/Windows, user-interface and graphics development kit. Derived from X/Winteracter, WiSK provides a library of subroutines for window management, input handling, dialog management, and high resolution graphics. Motif v2.2 is supported. Linux distributions such as Red Hat and SuSE are now shipping v2.2 as standard.

A new Resource Editor combines and improves the old menu and dialog editors and adds an image editor for icon, cursor, and bitmap-button creation. This substantially streamlines resource file maintenance. The included Winteracter Application Wizard provides a quick and easy method of generating a substantial starter application tailored to your needs.

A new Graphics Text(GT) group supersedes the Graphics Character Output group. The new GT interface is easier to understand and typically requires fewer subroutine calls. New features include the following: software fonts defined within the library rather than in external data files, thus eliminating the need to distribute and locate these files; all graphics text can optionally be plotted on an opaque background; underlining is available; text can be rotated and/or vertical; handling of proportional spacing has been improved, using ‘native’ font spacing, where available; vector-based software fonts can be drawn in a bold style; and character size is now expressed in a more meaningful manner. Numerous other enhancements: graphics can now be redirected to a dialog field instead of to a window. Windows and dialogs can now be combined. Menus can now be added to child windows in addition to the root window. Status bar help prompts can be attached to menu items. Support for progress bars is added. Routines to change the state of a field and move the cursor to a specific field are added. The mouse cursor is selectable and mouse double-clicks are reported.

BLAS is a library for vector and matrix operations. The BLAS thread-safe version is based on BLAS provided on Netlib. Included in LF95 v6.2 is an optimized version for the Pentium 4 with SSE2 instructions. BLAS includes 57 functions. The total number of routines for all precision types amounts to approximately 170.

BLAS thread-safe version provides the following routines:
Level 1 BLAS : Vector operations
Level 2 BLAS : Matrix and vector operations
Level 3 BLAS : Matrix and matrix operations
Sparse-BLAS : Sparse vector operations

The thread-safe implementation of BLAS has exactly the same subroutine names and calling parameters as those of the Netlib baseline version.

Differences include:

  • the thread-safe version can be used in the environment of SMP (Symmetric Multiple Processing)
  • subroutines of the thread-safe version can be called from an OpenMP Fortran program

The purpose of using BLAS thread-safe version is to have a subroutine concurrently perform operations on different sets of data that are independent from each other, and thus reduce the time necessary to finish all the operations.

LAPACK is a library of linear algebra routines. The LAPACK thread-safe version is based on LAPACK 3.0 provided on Netlib. Included in LF95 v6.2 is an optimized version for the Pentium 4 with SSE2 instructions. LAPACK includes approximately 300 functions. The total number of routines for all precision types amounts to approximately 1100.

LAPACK provides the following routines:

  • Linear equations
  • Linear least squares problems
  • Eigenvalue problems
  • Singular value decomposition

The LAPACK thread-safe version, like the BLAS version, can be called from an OpenMP program in the environment of SMP.


Fujitsu Scientific Subroutine Library 2
The Fujitsu Scientific Subroutine Library 2 (SSL2) has been in use for years in Japan on Fujitsu mainframe and workstation hardware. Included in LF95 v6.2 is an optimized version for the Pentium 4 with SSE2 instructions. SSL2 offers over 250 optimized thread-safe routines in the following areas:

Linear Algebra
Matrix Storage Mode Conversion
Matrix Manipulation
Linear Equations and Matrix Inversion (Direct Method)
Least Squares Solution

Eigenvalues and Eigenvectors
Eigenvalues and Eigenvectors of a Real Matrix
Eigenvalues and Eigenvectors of a Complex Matrix
Eigenvalues and Eigenvectors of a Real Symmetric Matrix
Eigenvalues and Eigenvectors of a Hermitian Matrix
Eigenvalues and Eigenvectors of a Real Symmetric Band Matrix
Eigenvalues and Eigenvectors of a Real Symmetric Generalized Eigenproblem
Eigenvalues and Eigenvectors of a Real Symmetric Band Generalized Eigenproblem

Nonlinear Equations
Polynomial Equations
Transcendental Equations
Nonlinear Simultaneous Equations

Minimization of Function with a Variable
Unconstrained Minimization of Multivariable Function
Unconstrained Minimization of Sum of Squares of Functions (Nonlinear Least Squares Solution)
Linear Programming
Nonlinear Programming (Constrained Minimization of Multivariable Function)

Interpolation and Approximation

Discrete Real Fourier Transforms
Discrete Cosine Transforms
Discrete Sine Transforms
Discrete Complex Fourier Transforms
Laplace Transform

Numerical Differentiation and Quadrature

Differential Equations

Special Functions
Elliptic Integrals
Exponential Integral
Sine and Cosine Integrals
Fresnel Integrals
Gamma Functions
Error Functions
Bessel Functions
Normal Distribution Functions

Pseudo Random Numbers
Pseudo Random Generation
Pseudo Random Testing

LF95 System Requirements

  • glibc 2.5 and higher (see below for tested distributions).
  • X-Windows to view online pdf manuals.
  • 35MB of available hard disk space for LF95 Express, 70MB for LF95 PRO.
  • 32MB RAM.
  • CD-ROM Drive.
  • 80486DX or Pentium-compatible processor


    LF95 v6.2 supported distributions

    To ensure compatibility with the following distributions, install the latest maintenance update.


    Distribution Kernel libc
    CentOS 5 2.6.18 2.5-18
    Fedora 8
    2.6.23 2.7-2
    Ubuntu 8.04
    2.6.24 2.7-10
    Open SUSE 10.3
    2.6.22 2.6.1




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