FORTRAN 77 Language Reference

REAL

For a declaration such as REAL W, the variable W is usually a REAL*4 element in memory, interpreted as a real number. Specifying the size is nonstandard. @

The default size, for a declaration such as REAL H, can be altered by compiling with any of the options -dbl, -r8, or -xtypemap. See the discussion in Chapter 2 for details.