Intel® Fortran Compiler Classic and Intel® Fortran Compiler Developer Guide and Reference

ID 767251
Date 7/13/2023
Public

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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

Valid REAL(8) or DOUBLE PRECISION Constants

123456789D+5

123456789E+5_8

+2.7843D00

-.522D-12

2E200_8

2.3_8

3.4E7_8

Invalid REAL(8) or DOUBLE PRECISION Constants

-.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