BUG: Compiling With -4Ya -Ox -4fps1 Causes Stack Corruption

• Microsoft Fortran PowerStation for Windows 95 and Windows NT, version 4.0

SYMPTOMS

An application that is compiled with the -4Ya -Ox -4fps1 compiler switches together causes stack data corruption at run time.

CAUSE

Multiple variables are being assigned to the same stack location.

RESOLUTION

Don't use these compiler switches together.

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

The following code illustrates the problem:

Sample Code

C Compile options needed: -4Ya -Ox -4fps1

      INTEGER NUMBER, DIVSOR, QUOT, REM
      NUMBER = 5
      DIVSOR = 2
      CALL DIVIDE (NUMBER, DIVSOR, QUOT, REM)

      PRINT *, 'Quotient : ', QUOT
      PRINT *, 'Remainder: ', REM
      END

      SUBROUTINE DIVIDE (NUMBER,DIVSOR,QUOT,REM)
      INTEGER NUMBER, DIVSOR, QUOT, REM, Q
      Q = NUMBER/DIVSOR
      REM = NUMBER-DIVSOR*Q
      QUOT = Q
      END

Quotient :           1
Remainder:           0

Quotient :           2
Remainder:           1