Intel® Fortran Compiler Classic and Intel® Fortran Compiler Developer Guide and Reference
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REAL(8) or DOUBLE PRECISION Constants
A REAL(8) or DOUBLE PRECISION constant has more than twice the accuracy of a REAL(4) number, and greater range.
A REAL(8) or DOUBLE PRECISION constant occupies eight bytes of memory. The number of digits that precede the exponent is unlimited, but typically only the leftmost 15 digits are significant.
IEEE* binary64 format is used.
Note that compiler option double-size can affect DOUBLE PRECISION data.
The default KIND for DOUBLE PRECISION is affected by compiler option double-size.
Examples
123456789D+5  |  
       
123456789E+5_8  |  
       
+2.7843D00  |  
       
-.522D-12  |  
       
2E200_8  |  
       
2.3_8  |  
       
3.4E7_8  |  
       
-.25D0_2  |  
        2 is not a valid kind for reals.  |  
       
+2.7182812846182  |  
        No D exponent designator is present; this is a valid single-precision constant.  |  
       
123456789.D400  |  
        Too large for any double-precision format.  |  
       
123456789.D-400  |  
        Too small for any double-precision format.  |  
       
See Also
Compiler Reference > Data and I/O section: Data Representation