TARGET Directive

インテル® Fortran コンパイラー 19.0 デベロッパー・ガイドおよびリファレンス

OpenMP* Fortran Compiler Directive: Creates a device data environment and executes the construct on that device. This directive only applies when targeting Intel® Xeon Phi™ products.

!$OMP TARGET [clause[[,] clause]... ]

block

!$OMP END TARGET

clause

Is one or more of the following:

DEFAULTMAP (TOFROM:SCALAR)

Causes a scalar variable to be treated as if it appeared in a MAP clause with a map-type of TOFROM.

If this clause is not specified, a scalar variable is not mapped; instead it has an implicit attribute of FIRSTPRIVATE. At most one DEFAULTMAP clause can appear in the directive.
DEPEND (dependence-type : list)
DEVICE (integer-expression)
IF ([TARGET:] scalar-logical-expression)
IS_DEVICE_PTR (list)

Indicates that a list item is a device pointer currently in the device data environment and that it should be used directly.

The list is one or more dummy arguments.

If a list item in a MAP clause is an array section, and the array section is derived from a variable with a POINTER or ALLOCATABLE attribute, then the behavior is unspecified if the corresponding list item’s variable is modified in the region.
MAP ([[map-type-modifier[,]] map-type: ] list)
NOWAIT

block

Is a structured block (section) of statements or constructs. No branching into or out of the block of code is allowed.

The binding task for a TARGET construct is the encountering task. The target region binds to the enclosing parallel or task region.

This construct provides a superset of the functionality provided by the TARGET DATA construct, except for the clause USE_DEVICE_PTR.

The TARGET construct also specifies that the region is executed by a device. The encountering task waits for the device to complete the target region at the end of the construct.

If a TARGET, TARGET DATA, or TARGET UPDATE construct appears within an OMP TARGET region, the construct is ignored.

If a variable appears in a REDUCTION or LASTPRIVATE clause on a combined construct for which the first construct is TARGET, it is treated as if it had appeared in a MAP clause with a map-type of TOFROM for REDUCTION and a map-type of FROM for LASTPRIVATE:

! SUM is treated as MAP (TOFROM)
!$OMP TARGET TEAMS DISTRIBUTE PARALLEL DO REDUCTION(+:SUM)

! X is treated as MAP (FROM)
!$OMP TARGET TEAMS DISTRIBUTE PARALLEL DO LASTPRIVATE(X)

A non-scalar variable referenced in a TARGET region and not explicitly mapped is implicitly treated as MAP (TOFROM):

INTEGER A(10)
!$OMP TARGET
  A(5) = 5          ! A is treated as MAP (TOFROM)
!$OMP  END TARGET

If only a subsection of a non-scalar variable has been mapped in an outer target region, and that variable is then mapped implicitly inside a nested target region, that variable should not access memory outside of the mapped subsection of the variable.

TARGET Directive

See Also