exp(3M)

NAME
     EXP, DEXP, CEXP, CDEXP - Computes exponential function

SYNOPSIS
     UNICOS and UNICOS/mk systems:

     EXP ([X=]x)
     DEXP ([X=]x)
     CEXP ([X=]x)

     UNICOS and IRIX systems:
     CDEXP ([X=]x)

IMPLEMENTATION
     UNICOS, UNICOS/mk, and IRIX systems

STANDARDS
     Fortran 90
     CDEXP is a compiler extension to Fortran 90.

DESCRIPTION
     EXP is the generic function name.  EXP, DEXP, and CEXP are elemental
     functions for the CF90 compiler.

     The entry point CDEXP is provided for support in other languages.  It
     is not recognized as an intrinsic function; therefore, you must use
     the CDIR$ VFUNCTION directive to allow vectorization.

     A vector version of this intrinsic exists on UNICOS and UNICOS/mk
     systems.  On UNICOS/mk systems, the vector version of this intrinsic
     is used when -h vector3 (C) or -O vector3 (Fortran) has been specified
     on the compiler command line.
                                   x
     These functions evaluate y = e .

   CF90
     CDEXP is called implicitly by the Fortran 90 compiler as a result of a
     generic EXP call with a complex double-precision argument.

   CAL Register Usage (Cray Research Systems Only)
     Scalar EXP:  EXP% (call-by-register)
          on entry   (S1) = argument
          on exit    (S1) = result

     Vector EXP:  %EXP% (call-by-register)
          on entry   (V1) = argument vector
          on exit    (V1) = result vector

     Scalar DEXP:  DEXP% (call-by-register)
          on entry   (S1) and (S2) = argument
          on exit    (S1) and (S2) = result

     Vector DEXP:  %DEXP% (call-by-register)
          on entry   (V1) and (V2) = argument vector
          on exit    (V1) and (V2) = result vector

     Scalar CEXP:  CEXP% (call-by-register)
          on entry   (S1) and (S2) = argument
          on exit    (S1) and (S2) = result
     Vector CEXP:  %CEXP% (call-by-register)
          on entry   (V1) and (V2) = argument vector
          on exit    (V1) and (V2) = result vector

     Scalar CDEXP:  %CEDXP% (call-by-register)
          on entry   (S1), (S2), (S3), and (V4) = argument
          on exit    (S1), (S2), (S3), and (S4) = result

     Vector CDEXP:  %CEDXP% (call-by-register)
          on entry   (V1), (V2), (V3), and (V4) = argument vector
          on exit    (V1), (V2), (V3), and (V4) = result vector

   Argument Range
     EXP, DEXP:
                 13
          |x| < 2   * ln 2

          On UNICOS/mk systems and on CRAY T90 systems that support IEEE
          arithmetic:

               x > -708.3964 and x < 709.7827

     CEXP:
                 13                    13
          |x| < 2   * ln 2 and |x | < 2   * ln 2
                                 r
     On UNICOS/mk systems and on CRAY T90 systems that support IEEE
     arithmetic:

          -708.3964 < x  < 709.7827
                       r
                  25
          |x | < 2
            i
     CDEXP:
                  13                 45
          |x | < 2   * ln 2, |x | < 2
            r                  i

NOTES
     CDEXP is an outmoded routine for the CF90 compiler.  Refer to the
     Fortran Language Reference Manual, Volume 3, publication SR-3905, for
     information about outmoded features and their preferred standard
     alternatives.

     The name of the EXP, DEXP, and CEXP intrinsic can be passed as an
     argument.  The name of the CDEXP intrinsic cannot be passed as an
     argument.

RETURN VALUES                                   x
     EXP returns the real exponential function e  of its real argument.
                                                             x
     DEXP returns the double-precision exponential function e  of its
     double-precision argument.
                                                    x
     CEXP returns the complex exponential function e  of its complex
     argument.
                                                            x
     CDEXP returns the complex double exponential function e  of its
     complex double-precision argument.

     On CRAY T90 systems that support IEEE arithmetic, the following return
     values occur:

          EXP(x) = 0 if x < -708.4

          EXP(x) = infinity if x > 709.78

          EXP(NaN) = NaN

SEE ALSO
     Intrinsic Procedures Reference Manual, publication SR-2138, for the
     printed version of this man page.