Microsoft Knowledge Base Article
This article contents is Microsoft Copyrighted material.
©2005-©2007 Microsoft Corporation. All rights reserved.
Terms
of Use |
Trademarks
Article ID: 74220 - Last Review: December 1, 2003 - Revision: 2.0
FIX: F1001: Grammar.c Line 91; Nested DO-Loops with Arrays
This article was previously published under Q74220
Compiling code using Microsoft FORTRAN versions 4.0, 4.01, 4.1, and
5.0 under MS-DOS, and versions 4.1 and 5.0 under OS/2, when that code
contains a subroutine with nested DO-loops in which arrays are indexed
using a DO variable from an outer DO-loop, may generate the following
error:
fatal error F1001: Internal Compiler Error
(compiler file '../../../P2/grammar.c', line 91)
The error can be suppressed by turning off loop optimization, using a
temporary variable in place of the DO variable from the outer DO-loop,
or by upgrading to FORTRAN 5.1.
Microsoft has confirmed this to be a problem in Microsoft FORTRAN
versions 4.0, 4.01, 4.1, and 5.0 for MS-DOS and versions 4.1 and 5.0
for OS/2. This problem was corrected in Microsoft FORTRAN 5.1.
This error is caused by a problem with loop optimization. The
following code generates the F1001 error:
Sample code
subroutine test(a,b,n)
real*8 a(6,12), b(6,6)
do 20 i=1,n
do 10 j=1,n
a(i,j+n)=b(i,j)
10 continue
20 continue
return
end
Compiling with the /Od option or with the /Odct options suppresses the
error. Microsoft FORTRAN version 5.1 will not generate the error.
If a temporary variable is used in place of the DO variable "i" in the
array subscript, the error will not generated. This allows full
optimization to be used when compiling. The following code
demonstrates this solution:
subroutine test(a,b,n)
real*8 a(6,12), b(6,6)
do 20 i=1,n
ii = i ! Temporary variable assigned value of i
do 10 j=1,n
a(ii,j+n)=b(ii,j) ! Temporary variable used in place of i
10 continue
20 continue
return
end
APPLIES TO
- Microsoft FORTRAN Compiler 4.0
- Microsoft FORTRAN Compiler 4.01
- Microsoft FORTRAN Compiler 4.1
- Microsoft FORTRAN Compiler 5.0
- Microsoft FORTRAN Compiler 4.1
- Microsoft FORTRAN Compiler 5.0
Retired KB Content DisclaimerThis article was written about products for which Microsoft no longer offers support. Therefore, this article is offered "as is" and will no longer be updated.
Community Feedback System
Very often, it takes hours to solve a problem. Very often, you've looked high
and low, and have tried a lot of solutions. When you finally found it, chances
are, it was because someone else helped you. Here's your chance to give back.
Use our community feedback tool to let others know what worked for you and what
didn't.
Please also understand that the community feedback system is not warranted to be
correct, it's simply a system that we've built to let people try and help each
other. If something in a feedback response doesn't make sense to you, or you're
not comfortable making changes that the feedback talks about (like registry
edits), please consult a professional.
Thank you for using kbAlertz.com Feedback System.
-- Scott Cate