DOCUMENT:Q104891  24-MAR-2000  [fortran]
TITLE   :FIX: F1001 "@(#)fltreg.c:1.31" When Compiling with /Ox
PRODUCT :Microsoft Fortran Compiler
PROD/VER::1.0
OPER/SYS:
KEYWORDS:

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-------------------------------------------------------------------------------
The information in this article applies to:

 - Microsoft FORTRAN PowerStation for MS-DOS, version 1.0 
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SYMPTOMS
========

A complex series of expressions may generate the Internal Compiler Error F1001
in file "@(#)fltreg.c:1.31" when compiled with full optimization (/Ox).

RESOLUTION
==========

Adding the compiler switch /Op for floating-point consistency may avoid this
error message. Removing the compiler switch /Ox may also resolve this problem.
Breaking down the complex expressions using temporary variables is also a
recommended solution.

STATUS
======

Microsoft has confirmed this to be a problem in FORTRAN PowerStation for MS-DOS,
version 1.0. This problem has been resolved with FORTRAN powerstation
maintenance release version 1.0a for MS-DOS.

FORTRAN PowerStation version 1.0 can be differentiated from maintenance release
version 1.0a by invoking the linker. Typing "Link32 | more" (without the
quotation marks) from \F32\BIN directory will show version 2.8 for FORTRAN
Powerstation version 1.0, and it will show version 1.0f for the maintenance
release version 1.0a.

MORE INFORMATION
================

Some code compiled with the /Ox switch may generate the following error
message:

   fatal error F1001: INTERNAL COMPILER ERROR
   compiler file '@(#)fltreg.c:1.31', line 4792

Depending on the contents of the file being compiled, the line could also be
2634.

To duplicate this error message, compile the following code with only the /Ox
option. This sample produces the line 4792 message.

To resolve the problem, add the /Op option or remove the /Ox option. Also, almost
any simplification or restructuring of the equations will remove the error. For
example, uncomment the "temp =" line.

This code compiles without any error with Microsoft FORTRAN 5.1 or earlier.

Sample Code
-----------

   C Compiler options required: /Ox and not /Op
         DIMENSION BN(30)
         COMMON ALPA, DN, THT, NP1, K, BN
   c      temp = ALPA**((DN+1.0D0)*THT)
         SR=ALPA**(DN*THT)+BN(NP1)*0.5D0*ALPA**((DN+1.0D0)*THT)
         UTH=DSIN(THT)-BN(NP1)*0.5D0/ALPA**((DN+1.0D0)*THT)
         URB=ALPA**DCOS(DN*THT)*(DN-1.0D0)
         SRK2=(1.0D0)**ALPA**(K-1)
         UTHK2=(-1.0D0)**ALPA**K
         END

Additional query words: 1.00

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Keywords          :  
Technology        : kbAudDeveloper kbFortranSearch kbZNotKeyword3 kbFORTRANPower100DOS
Version           : :1.0
Issue type        : kbbug
Solution Type     : kbfix

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