Microsoft KB Archive/150134

= BUG: FOR4165 Warning Underflow of Smallest Positive REAL*8 =

PSS ID Number: 150134

Article Last Modified on 11/2/1999

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The information in this article applies to:


 * Microsoft Fortran PowerStation for Windows 95 and Windows NT 4.0

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This article was previously published under Q150134



SYMPTOMS
Compiling a source file that contains an assignment of the smallest positive REAL*8 literal constant to a REAL*8 or DOUBLE PRECISION variable causes the following compiler warning message:

warning FOR4165: underflow in REAL literal constant 2.225073858507201D-308



RESOLUTION
Use the TINY intrinsic function to convert a number to the smallest positive REAL*8 value, and then use the result in your calculations.



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.



Sample Code to Illustrate Problem and Workaround
C Compile options needed: none

REAL*8 dx     DOUBLE PRECISION dy      dx = 2.225073858507201D-308  ! Warning - 0.000000000000000 assumed write (*,*) dx     dy = tiny(1.d0)   ! work-around - dy = 2.225073858507201d-308 write (*,*) dy     END

Program Output
0.000000000000000E+000

2.225073858507201E-308

Additional query words: 4.00

Keywords: kbLangFortran KB150134

Technology: kbAudDeveloper kbFORTRANPower400NT kbFortranSearch kbZNotKeyword8

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