Intel Fortran Language Reference - NCI National Facility

1 Intel Fortran Language Reference
• The FORALL statement and construct
In Fortran 90, you could build array values element-by-element by using array constructors
and the RESHAPE and SPREAD intrinsics. The Fortran 95 FORALL statement and construct
offer an alternative method.
FORALL allows array elements, array sections, character substrings, or pointer targets to be
explicitly specified as a function of the element subscripts. A FORALL construct allows
several array assignments to share the same element subscript control.
FORALL is a generalization of WHERE. They both allow masked array assignment, but
FORALL uses element subscripts, while WHERE uses the whole array.
For more information, see “FORALL Statement and Construct”.
• PURE user-defined procedures
Pure user-defined procedures do not have side effects, such as changing the value of a
variable in a common block. To specify a pure procedure, use the PURE prefix in the function
or subroutine statement. Pure functions are allowed in specification statements.
For more information, see “Pure Procedures”.
• ELEMENTAL user-defined procedures
An elemental user-defined procedure is a restricted form of pure procedure. An elemental
procedure can be passed an array, which is acted upon one element at a time. To specify an
elemental procedure, use the ELEMENTAL prefix in the function or subroutine statement.
For more information, see “Functions” and “Subroutines”.
• CPU_TIME intrinsic subroutine
This new intrinsic subroutine returns a processor-dependent approximation of processor time.
For more information, see “CPU_TIME”.
• NULL intrinsic function
In Fortran 90, there was no way to assign a null value to the pointer by using a pointer
assignment operation. A Fortran 90 pointer had to be explicitly allocated, nullified, or
associated with a target during execution before association status could be determined.
Fortran 95 provides the NULL intrinsic function that can be used to nullify a pointer.
For more information, see “NULL”.
• New obsolescent features
Fortran 95 deletes several language features that were obsolescent in Fortran 90, and
identifies new obsolescent features.
Intel Fortran fully supports features deleted in Fortran 95.
For more information, see Appendix A, “Deleted and Obsolescent Language Features”.
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