Pro Fortran 8.0/F77 SDK 5.6 for Intel/Linux Technical FAQs
Updated: 23-Apr-03

Segmentation violation on Linux                                            01-Sep-02
Fx on Linux can't see C Source files                                       01-Sep-02
IMSL documentation                                                         01-Sep-02
Supporting -r8 flag in Fortran77                                           01-Sep-02
F90 cannot find functions in modules                                       01-Sep-02
F90 error message problems                                                 01-Sep-02
Using the ABSOFT_RT_FLAGS environment variable                             23-Apr-03
Fortran string lengths                                                     01-Sep-02
setting xfx source paths                                                   01-Sep-02
Problems linking functions compiled with g77                               01-Sep-02
Adjustable array is not a dummy argument                                   01-Sep-02
Controlling the FPU in Linux                                               01-Sep-02
Static linking on Linux                                                    01-Sep-02
Core dump with HUGE executables                                            01-Sep-02
Linking to g77 and gcc                                                     01-Sep-02
Is there an F90 compiler option for big or little endian?                  01-Sep-02
IMSL linking problem                                                       15-Oct-02
I can't get the VMS (or Unix) libraries to link                            01-Sep-02
Using more than 2GB of addressable memory                                  01-Sep-02
F90 error message problems                                                 01-Sep-02
Unable to initialize Fx interface, check value of TERM                     01-Sep-02
Linker warnings on Linux                                                   01-Sep-02
Using glibc version 2.3.1(sys_errorlist deprecated, errno undefined)       17-Apr-03
execv of /usr/bin/as failed                                                11-Apr-03

Platform: Intel/Linux

Problem Details:
OS Version: 2.0
Product Version: any
Date: 01-Sep-02

Q. When I declare large arrays (>8 MB of variables), I get a
   segmentation violation from Linux.

A. Use the "-s" compiler option (static storage) to move
   the data from the stack to the heap or use the ulimit
   command (ulimit is a bash command - the csh equivalent to
   'ulimit -s' is 'limit stack') to raise the stack size limit
   # ulimit -s
   8192
   # ulimit -s 32768
   # ulimit -s
   32768

   Once raised the limit applies to the current
   process and any children of that process.

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Platform: Intel/Linux

Problem Details:
OS Version: Linux 1.2 and 2.*
Product Version: any
Date: 01-Sep-02

Q. I am trying to debug a mixed language program on Linux. Even though
   my C files are compiled with -g, Fx can't see them.

A. You need to compile the C files with -gdwarf instead of -g.

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Platform: All

Problem Details:

OS Version: any
Product Version: any
Date: 01-Sep-02

Q. Where can I find IMSL documentation.

A. The documentation for the IMSL libraries (7 volume set) may be
   purchased separately, or you can find it on line at:

   http://www.vni.com/products/imsl/alphabetized_functions.html

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Platform: Intel/Linux

Problem Details:

OS Version: Any
Product Version: Fortran77
Date: 01-Sep-02

Q. Does FORTRAN 77 support the -r8 flag?

A. Use the -N113 compiler option.

The -N2 option forces all intrinsic functions to be performed
in DOUBLE PRECISION.

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Platform: Intel/Linux

Problem Details:

OS Version: any
Product Version: any
Date: 01-Sep-02

Q. I have a file which "uses" a precompiled module containing a
   function used by the main file. When I try to compile the main it
   says there is an unresolved reference.

A. Your module contains executable code. Precompiling it created both
   a module file and an object file. Present the object file to the linker
   and the reference will be resolved. If you're compiling from the
   command line, simply add the object file on the compiler invocation
   line.

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Platform: Intel/Linux

Problem Details:

OS Version: any
Product Version: ProFortran 8.0
Date: 01-Sep-02

Q. When I try to compile a program with the Fortran 90
   compiler I get the following error message:

   cft90 INTERNAL: Cannot retrieve message 3 from the message system.

   What does this message mean?

A. The error message file is:

   /opt/absoft/nls/cf90

   This path is hard-wired into the compiler. However, if an
   environment variabled named NLSPATH is defined, the compiler
   will use it to attempt to locate the message file. Either
   unset this variable when you are using the Fortran 90 compiler,
   or add the path specified above to the variable:

   NLSPATH=/opt/absoft/lib/nls/cf90/
   export NLSPATH

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Platform: all
OS version: any
           
Product Version: Pro Fortran 6.0 and later
Q. How can I modify the default behavior of the Absoft runtime library?
A. Starting with Absoft Pro Fortran 6.0 and Absoft Fortran SDK 4.5, the
           runtime library checks for an environment variable named ABSOFT_RT_FLAGS
           on entry to the first I/O statement in a program. 
          The following switches can be specified using this variable:
      -defaultcarriage:            
           
           Causes the units preconnected to standard output to interperet 
           carriage control characters as if they had been connected with
           ACTION='PRINT'.
       -fileprompt: 
           Causes the library to prompt the user for a filename when it 
           implicitly opens a file as the result of I/O to an unconnected
           unit number. By default, the library creates a filename based on
           the unit number.
       -vaxnames: 
           Causes the library to use 'vax style' names (FORnnn.DAT) when 
           creating a filename as the result of I/O to an unconnected
           unit number.
        -unixnames: 
           Causes the library to use 'unix style' names (fort.nnn) when 
           creating a filename as the result of I/O to an unconnected 
           unit number.
        -bigendian: 
           Causes the library to interpret all unformatted files using 
           big endian byte ordering.
         -littleendian:            
           Causes the library to interpret all unformatted files using 
           little endian byte ordering.
         -noleadzero: 
            Causes the library to surpress the printing of leading zeroes
            when processing an Fw.d edit descriptor. This only affects the 
            limited number of cases where the ANSI standard makes printing 
            of a leading zero implementation defined. 
         -reclen32: 
            Causes the library to interpret the value specified for RECL= 
            in an OPEN statement as 32-bit words instead of bytes.
          -f90nlexts:
            Allows f90 namelist reads to accept non-standard syntax for
            array elements. Without this flag, the following input results
            in a runtime error:
             $ONE
             A(1)=1,2,3,4
             $END
           
             When -f90nlexts is set, the values are assigned to the first
             four elements of A.
          -nounit9
             Causes UNIT 9 not to be preconnected to standard input and output.
          -maceol
              Formatted sequential files are in Classic Macintosh format where each
              record ends with a carriage return,
          -doseol
               Formatted sequential files are in Windows format where each record ends
               with a carriage return followed by a line feed.
          -unixeol
               Formatted sequential files are in Unix format where each record ends with a line feed.
          -hex_uppercase
                Data written with the Z edit descriptor will use upper case characters for A-F.
          To set ABSOFT_RT_FLAGS:
           On Windows:
           Open a command prompt window and enter:
           set ABSOFT_RT_FLAGS=-fileprompt
           On Mac OS 9:
           Open the MPW worksheet and enter:
           set -e ABSOFT_RT_FLAGS -fileprompt
           On Mac OS X(using tcsh):
           Open the terminal and enter:
           setenv ABSOFT_RT_FLAGS -fileprompt
           On Linux(using bash):
           export ABSOFT_RT_FLAGS=-fileprompt
           MRWE applications must be launched from the 
           command line so that the ABSOFT_RT_FLAGS
           will be used.

           Note: the leading minus sign is required for each switch and multiple            
           switches must be separated by one or more spaces.

 

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Platform: All

Problem Details:
OS Version: All
Product Version: All
Date: 01-Sep-02

Q. Does Absoft Fortran pass the lengths of strings like most Unix
Fortran compilers I've used?
A. Yes, string lengths are passed as extra arguments (by value) at 
the end of the formal argument list: APF75SP:cat t.f subroutine Fcode(string, i, d)
   character*(*) string
   integer i
   value i
   double precision d
   print *, string, i, d, len(string)
   end
   APF75SP:cat c.c
   #include <string.h>
   void Fcode(char *, int, double *, int);
   int main()
   {
   char string[13] = {"hello, world"};
   int i = 1;
   double d = 2.0;
   Fcode(string, i, &d, strlen(string));
   return 0;
   }
   APF75SP:f77 t.f c.c
   FORTRAN 77 Compiler 7.5a, Copyright (c) 1987-2002, Absoft Corp.
   APF75SP:a.out
   hello, world 1 2.00000000000000 12
   For more information on mixed Fortran and C programming
   See chapter 4 in the Pro Fortran for Linux user guide on
   Interfacing with other languages.

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Platform: Intel/Linux

Problem Details:

OS Version: Linux
Product Version: any
Date: 01-Sep-02

Q. Is there an execution argument for "xfx" that sets the path
   in which it should search for sources?

A. You can use an environment variable or a command line
   argument:

   export FXSRCPATHS={colon separated list of directories}

   or:

   xfx -p {colon separated list of directories}

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Platform: Intel/Linux

Problem Details:

OS Version: Linux
Product Version: Any
Date: 01-Sep-02

Q. I am trying to link to some functions compiled with g77. When I compile my
   program I get linker errors and undefined reference to any of the necessary
   functions.

A. Include the g77 runtime library libf2c.a in your compile line to make it an
   argument to the linker.

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Platform: All

Problem Details:
OS Version: Any
Product Version: Any
Date: 01-Sep-02

Q. I get the error message:
	"adjustable array is not a dummy argument"

A. The most common cause of this is:

   subroutine some_name(a,b,n)
   real A(N), B(N)

   The FORTRAN 77 compiler is case sensitive by default.
   The easiest way to solve this type of problem is use a
   case folding option: -f or -N109.

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Platform: Intel/Linux

Problem Details:

OS Version: Linux
Product Version: any
Date: 01-Sep-02

Q. How can I control the processor FPU?

A. You can use arm387 to control the FPU. This is an
   integer function built into the runtime library. Here
   are the definitions of the control arguments:

fenv.inc:

! Intel specific FPU control constants for use with fpcontrol

        integer*4 FE_TONEAREST
        parameter ( FE_TONEAREST  = (z'00000000'))

        integer*4 FE_TOWARDZERO
        parameter ( FE_TOWARDZERO = (z'00000C00'))

        integer*4 FE_UPWARD
        parameter ( FE_UPWARD     = (z'00000800'))

        integer*4 FE_DOWNWARD
        parameter ( FE_DOWNWARD   = (z'00000400'))

        integer*4 FE_INEXACT
        parameter ( FE_INEXACT    = (z'00000020'))

        integer*4 FE_DIVBYZERO
        parameter ( FE_DIVBYZERO  = (z'00000004'))

        integer*4 FE_UNDERFLOW
        parameter ( FE_UNDERFLOW  = (z'00000010'))

        integer*4 FE_OVERFLOW
        parameter ( FE_OVERFLOW   = (z'00000008'))

        integer*4 FE_INVALID
        parameter ( FE_INVALID    = (z'00000001'))


Then use arm387 as follows:

test.f:

        implicit none
        include "fenv.inc"
        integer arm387
        integer state

* first retrieve the current state of the FPU

        state = arm387(0)

* enable divide-by-zero exceptions (for example)

        state = arm387(state .and. .not. FE_DIVBYZERO)


        end

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Platform: Intel/Linux

Problem Details:

OS Version: Linux
Product Version: any
Date: 01-Sep-02

Q. If I want executable files to run on other linux systems
   which do not have the Absoft compiler installed, do I need
   to link the libraries statically or does that happen automatically?

A. In order to statically link the libraries you must pass
   an argument to the linker on the command line like this:

   -X -static

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Platform: Intel/Linux

Problem Details:

OS Version: Linux
Product Version: any
Date: 01-Sep-02

Q. I have a program with some very large arrays; 500 MB
   and more. I have plenty of memory in my computer, but
   the program still core dumps immediately.

A. First, be certain that you are using the '-s' (static
   storage) compiler option (f77 or f90). The default Linux
   stack size of 8 MB will not be sufficient.

   This is a problem with the Linux dynamic loader. You should
   be able to solve the problem by linking against static
   versions of the system libraries to avoid dynamic linking.
   Add this option to your compiler command line:

   -X -static

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Platform: Intel/Linux

Problem Details:

OS Version: Linux
Product Version: 8.0
Date: 01-Sep-02

Q. I am trying to use a compiled g77 object with Absoft
   f77 or f90 and I receive these errors:

    test.o(.text+0x9): undefined reference to `s_wsle'
    test.o(.text+0x22): undefined reference to `do_lio'
    test.o(.text+0x2a): undefined reference to `e_wsle'

A. You must link against the g77 runtime library f2c or g2c
   depending on your Linux distribution.

Q. Ok, I added -lg2c and I still get an unresolved reference
   to the g77 subroutine that I am trying to call in F77?

A. G77 folds all external names to lower case and appends
   a trailing underscore. You must add the -B108 and -f compiler
   options. Your compile line should look like this:

   f77 t.f test.o -lg2c -B108 -f

   For F90 you must also add -YEXT_NAMES="LCS"
   which folds all external symbolic names to lower case
   and -B108 that appends a trailing underscore.
   Your compile line should look like this:

   f90 t.f test.o -lg2c -B108 -YEXT_NAMES="LCS"

Q. I am trying to use F77 with gcc.  My C code compiles fine.  When
   I try to use the compiled gcc object code with F77, I receive unresolved
   references for every call to the C math library that is in my C code?

A. Add libm.a to your compile line like this:

       f77 t.f test.o -lm

Q. Is there an equivalent of -fno-second-underscore in your compiler?
   I need to be able to link g77/gcc produced code that is compiled with this option.

A. Do not use the -B108 f77/f90 compiler option. This is a back-end (code generator)
   option and has specific knowledge of the Linux environment; hence the double underscores.
   Instead, use a front-end option which is machine independent:

   f77: -N15
   f90: -YEXT_SFX='_'

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Platform: All

Problem Details:
OS Version: Any
Product Version: Any
Date: 01-Sep-02

Q. Is there an F90 compiler option that will force the compiler to
   consider the byte ordering of all unformatted files to either big
   or little endian?

A. Use the F90 open statement specifier:
   convert ={"big_endian"|"little_endian"}

   For example:

   Open(10,file="filename",form="unformatted",convert="big_endian")

   Or, use the ABSOFT_RT_FLAGS as described in the technical FAQ on
   using the ABSOFT_RT_FLAGS environment variable which can
   be found here:

   linux75tfaq.html#anchor0058

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Platform: Intel/Linux
Problem Details:
OS Version: Linux
Product Version: 8.0
Date: 01-Sep-02
Q. I can't get the VMS (or Unix) libraries to link.
A. The libraries contain three entry points for each function.
   One in all upper case, one in all upper case with a trailing underscore,
   and one in all lower case with a trailing underscore:
   DATE
   DATE_
   date_
   Be sure that your spelling matches one of these.
   The libraries are maintained in /opt/absoft/lib:
   /opt/absoft/lib/libV77.a VMS compatibility library
   /opt/absoft/lib/libU77.a Unix compatibility library
   For example:
   test.f:
   character*40 argument
   n = IARGC()
    do i=1,n
     call GETARG(i,argument)
     print *,trim(argument)
    end do
   end
   $ f77 -1U77 test.f


   The VMS and Unix libraries are documented in:
   /opt/absoft/doc/supportLibrary.pdf

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Platform: All

Problem Details:
OS Version: Any
Product Version: 8.0
Date: 01-Sep-02

Q. Using more than 2GB of addressable memory

A. The following table shows the maximum process size (code+data)
on each operating system:
                     OS | Max process size
   ---------------------+--------------------
   x86 Linux kernel 2.4 | 3GB
   x86 Linux kernel 2.2 | 2GB
              PPC Linux | 2GB
                Windows | 2GB
                Mac OSX | 2GB, 64MB max stack
   In addition to those limits, f90 has a limit of a maximum of 512MB
   for any single array or common block. This limit is scheduled to be
   removed from f90 in the next release after version 7.5.
   F77 has a limit of 2GB for any single array, and 2,000,000,000 bytes
   for any single common block.
   To have the maximum amount of memory available for data on Linux,
   it is necessary to link your application statically. This is done
   by using the "-X -static" option for either f77 or f90.
   On x86 Linux there is also a limit in the GNU assembler that
   you can't have more than 2GB of static data (either save
   statements, or the -s switch) in a single file. If you try,
   you will get the following error: Error: attempt to .org backwards ignored
   To work around this, you can put some data into a common block.

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Platform: Intel/Linux

Problem Details:

OS Version: Linux
Product Version: any
Date: 01-Sep-02

Q. I am trying to debug a mixed language program on Linux. Even though
my C files are compiled with -g, Fx can't see them. A. You need to compile the C files with -gdwarf instead of -g.

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Platform: Intel/Linux

Problem Details:

OS Version: Linux
Product Version: any
Date: 01-Sep-02

Q. When I try to compile a program with the Fortran 90 
compiler I get the following error message:

cft90 INTERNAL: Cannot retrieve message 3 from the message system.

What does this message mean?
A. The error message file is:
   NLSPATH=/usr/lib/absoft/nls/%N
   This path is hard-wired into the compiler. However, if an
   environment variabled named NLSPATH is defined, the compiler
   will use it to attempt to locate the message file. Either
   unset this variable when you are using the Fortran 90 compiler,
   or add the path specified above to the variable:
   NLSPATH=/usr/lib/absoft/nls/cf90/%N
   export NLSPATH

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Platform: Intel/Linux

Problem Details:

OS Version: Linux
Product Version: any
Date: 01-Sep-02
Q. Everytime I launch the curses version of Fx, I get the following error:
   Unable to uinitialize Fx interface, check value of TERM.
   I check the value of TERM and it seems ok. 
A. The location of the terminfo database moved in RedHat 6.0. Fx is looking
for /usr/lib/terminfo, but the database is now located in /usr/share/terminfo.
You can fix this problem by setting the value of an enviornment variable
named TERMINFO to the correct location.
   set TERMINFO=/usr/share/terminfo
   export TERMINFO
   or

   setenv TERMINFO /usr/share/terminfo

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Platform: Intel/Linux

Problem Details:

OS Version: Suse Linux
Product Version: any
Date: 01-Sep-02
Q. Every time I compile a program I get a warning message like:
   "warning: multiple common of `_io_comm'"
   "warning: previous common is here"
A. You are probably using a SuSE implementation of Linux.   For 
unknown reasons, they configure the C compiler to use the
default option: "-warn-common". This causes the warnings you
are seeing.
   You can eliminate these warnings by reconfiguring your default
   options maintained in the "specs" file for gcc.
   On SuSE 6.0, edit the file:
   /usr/lib/gcc-lib/i486-linux/egcs-2.91.60/specs
   and remove ONLY -warn-common from the *.lib section
   On SuSE 6.1 and SuSE 6.2, edit the file
   /usr/lib/gcc-lib/i486-linux/egcs-2.91.66/specs
   and remove ONLY -warn-common from the *.lib section

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Platform: Intel/Linux

Problem Details:

OS Version: Linux
Product Version: 8.0
Date: 15-Oct-02

Q. I'm having problems using the IMSL functions. The linker reports
unresolved references for any function I try to use.
A. You must include the IMSL and BLAS libraries:
      libimsl.a and libimslblas.a
      as an argument to the linker like this:
      f77 t.f -f -N15 -limsl -limslblas
      f90 a.f -limsl -limslblas -YEXT_NAMES=LCS -YEXT_SFX=_

      It is necessary to add the options -f(fold to lower case)
      and the -N15(appends a trailing underscore) for F77 and
      the corresponding F90 options, -YEXT_NAMES=LCS -YEXT_SFX=_
      because the IMSL and BLAS libraries were compiled with these options.

      The complete documentation which includes
      Fortran source code examples is included in
      /opt/absoft/doc
      F9040.pdf
      MATH.pdf
      SFUN.pdf
      STATVol1.pdf
      STATVol2.pdf
            

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Platform: Intel/Linux

Problem Details:

OS Version: Linux
Product Version: 8.0
Date: 17-Apr-03


Q. I am using glibc version 2.3.1 (Red Hat 9, Mandrake 9.1, Suse 8.2 etc.), I
see the following errors when trying to link my Fortran programs:

/opt/absoft/lib/libfio.a(ioerr.o)(.text+0x1fb): In function `_ioerr':
: `sys_errlist' is deprecated; use `strerror' or `strerror_r' instead
/opt/absoft/lib/libfio.a(open.o)(.text+0xc79): In function `_f_open3':
: undefined reference to `errno'
collect2: ld returned 1 exit status


A. This updated version of the GNU C library requires that you apply
a patch to update the Absoft I/O library:
The patch is available at
http://www.absoft.com.

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Platform: Intel/Linux

Problem Details:

OS Version: Linux
Product Version: Any
Date: 11-Apr-03
Q. I receive the error message "execv of /usr/bin/as failed"
   when building my programs.
A. "execv of /usr/bin/as failed" indicates that you do not have the system
assembler installed. "as" is part of the package known as "binutils".If you have your
Linux Distribution cd (and it is an RPM based distro), locate the package:
binutils<version number>.rpm
   When you find the RPM on your cd, you can install it by typing:
   rpm -i <filename>.rpm
   You may also look on the internet for an RPM or other package for your Linux distribution.
   binutils source:
   http://www.gnu.org/directory/binutils.html
         

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