Intel® Fortran Compiler 16.0 User and Reference Guide

Intrinsic Procedures Overview

Intrinsic procedures are functions and subroutines that are included in the Fortran library. There are four classes of these intrinsic procedures, as follows:

An atomic subroutine is an intrinsic subroutine that performs an action on a variable (its ATOM argument) atomically. When an atomic subroutine is executed, it is as if the subroutine were executed instantaneously without overlapping other atomic actions that might occur asynchronously.

Intrinsic procedures are invoked the same way as other procedures, and follow the same rules of argument association.

The intrinsic procedures have generic (or common) names, and many of the intrinsic functions have specific names. (Some intrinsic functions are both generic and specific.)

In general, generic functions accept arguments of more than one data type; the data type of the result is the same as that of the arguments in the function reference. For elemental functions with more than one argument, all arguments must be of the same type (except for the function MERGE).

When an intrinsic function is passed as an actual argument to a procedure, its specific name must be used, and when called, its arguments must be scalar. Some specific intrinsic functions are not allowed as actual arguments in all circumstances. The following table lists specific functions that cannot be passed as actual arguments or as targets in procedure pointer assignment statements.

Specific Intrinsic Functions Not Allowed as Actual Arguments

AIMAX0

FLOATJ

JFIX

MAX0

AIMIN0

FLOATK

JIDINT

MAX1

AJMAX0

FP_CLASS

JIFIX

MIN0

AJMIN0

HFIX

JINT

MIN1

AKMAX0

IADDR

JIQINT

NARGS

AKMIN0

IARGC

JMAX0

QCMPLX

AMAX0

ICHAR

JMAX1

QEXT

AMAX1

IDINT

JMIN0

QEXTD

AMIN0

IFIX

JMIN1

QMAX1

AMIN1

IIDINT

JNUM

QMIN1

CHAR

IIFIX

JZEXT

QNUM

CMPLX

IINT

KIDINT

QREAL

DBLE

IIQINT

KIFIX

RAN

DBLEQ

IJINT

KINT

RANF

DCMPLX

IMAX0

KIQINT

REAL

DFLOTI

IMAX1

KMAX0

RNUM

DFLOTJ

IMIN0

KMAX1

SECNDS

DFLOTK

IMIN1

KMIN0

SHIFTL

DMAX1

INT

KMIN1

SHIFTR

DMIN1

INT1

KNUM

SNGL

DNUM

INT2

KZEXT

SNGLQ

DREAL

INT4

LGE

ZEXT

DSHIFTL

INT8

LGT

DSHIFTR

INUM

LLE

FLOAT

IQINT

LLT

FLOATI

IZEXT

LOC

Note that none of the intrinsic subroutines can be passed as actual arguments or as targets in procedure pointer assignment statements.

The A to Z Reference contains the descriptions of all intrinsics listed in alphabetical order. Each reference entry indicates whether the procedure is inquiry, elemental, transformational, or nonelemental, and whether it is a function or a subroutine.

See Also