OpenMP* Pragmas Summary

PARALLEL Pragma

Use this pragma to form a team of threads and execute those threads in parallel.

Pragma	Description
omp parallel	Specifies that a structured block should be run in parallel by a team of threads.

TASKING Pragma

Use this pragma for deferring execution.

Pragma	Description
omp task	Specifies the beginning of a code block whose execution may be deferred.

WORKSHARING Pragmas

Use these pragmas to share work among a team of threads.

Pragma	Description
omp for	Specifies a parallel loop. Each iteration of the loop is executed by one of the threads in the team.
omp sections	Defines a region of structured blocks that will be distributed among the threads in a team.
omp single	Specifies a structured block that will be executed only once by a single thread in the team.

SYNCHRONIZATION Pragmas

Use these pragmas to synchronize between threads.

Pragma	Description
omp atomic	Specifies a computation that must be executed atomically.
omp barrier	Specifies a point in the code where each thread must wait until all threads in the team arrive.
omp critical	Specifies a code block that is restricted to access by only one thread at a time.
omp flush	Identifies a point at which the view of the memory by the thread becomes consistent with the memory.
omp master	Specifies the beginning of a code block that must be executed only once by the master thread of the team.
omp ordered	Specifies the beginning of a code block that must be executed only once by the master thread of the team.
omp taskgroup	Causes the program to wait until the completion of all enclosed and descendant tasks.
omp taskwait	Specifies a wait on the completion of child tasks generated since the beginning of the current task.
omp taskyield	Specifies that the current task can be suspended at this point, in favor of execution of a different task.

Data Environment Pragma

Use this pragma to give threads global private data.

Pragma	Description
omp threadprivate	Specifies a list of globally-visible variables that will be allocated private to each thread.

Coprocessor Control Pragmas

Use these pragmas to control execution on one or more coprocessors.

Pragma	Description
omp declare target	Specifies functions and variables that are created or mapped to a device. This pragma only applies to Intel® Many Integrated Core Architecture (Intel® MIC Architecture) and Intel® Graphics Technology.
omp distribute	Specifies that the iterations of one of more loops should be shared among the master threads of all thread teams in a league.
omp target	Creates a device data environment and then executes the construct on that device. This pragma only applies to Intel® MIC Architecture and Intel® Graphics Technology.
omp target data	Creates a device data environment by making a mapping of variables from the host to the target device. This pragma only applies to Intel® MIC Architecture.
omp target update	Makes the items listed in the device data environment consistent between the device and host, in accordance with the motion clauses on the pragma. This pragma only applies to Intel® MIC Architecture.
omp teams	Creates a league of thread teams to execute the structured block in the master thread of each team.

Vectorization Pragmas

Use these pragmas to control execution on vector hardware.

Pragma	Description
omp simd	Transforms the loop into a loop that will be executed concurrently using Single Instruction Multiple Data (SIMD) instructions.
omp declare simd	Creates a version of a function that can process multiple arguments using Single Instruction Multiple Data (SIMD) instructions from a single invocation from a SIMD loop.

Cancellation Constructs

Pragma	Description
omp cancel	Requests cancellation of the innermost enclosing region of the type specified, and causes the encountering task to proceed to the end of the cancelled construct.
omp cancellation point	Defines a point at which implicit or explicit tasks check to see if cancellation has been requested for the innermost enclosing region of the type specified. This construct does not implement a synchronization between threads or tasks.

User-Defined Reduction Pragma

Use this pragma to define reduction identifiers that can be used as reduction operators in a reduction clause.

Pragma	Description
omp declare reduction	Declares User-Defined Reduction (UDR) functions (reduction identifiers) that can be used as reduction operators in a reduction clause.

Combined Pragmas

Use these pragmas as shortcuts for multiple pragmas in sequence.

Pragma	Description
omp distribute parallel for	Specifies a loop that can be executed in parallel by multiple threads that are members of multiple teams.
omp distribute parallel for simd	Specifies a loop that will be executed in parallel by multiple threads that are members of multiple teams. It will be executed concurrently using SIMD instructions.
omp distribute simd	Specifies a loop that will be distributed across the master threads of the teams region. It will be executed concurrently using SIMD instructions.
omp for simd	Specifies the beginning of a loop that can be executed concurrently using Single Instruction Multiple Data (SIMD) instructions. Each iteration of the loop is executed by one of the threads in the team.
omp parallel for	Specifies a parallel construct containing one or more associated loops.
omp parallel for simd	Specifies a parallel region that contains a loop to execute with Single Instruction Multiple Data (SIMD) instructions.
omp parallel sections	Specifies a parallel construct that contains a single sections construct.
omp target teams	Creates a device data environment and executes the construct on the same device. It also creates a league of thread teams with the master thread in each team execution the structured block.This pragma only applies to Intel® MIC Architecture.
omp target teams distribute	Creates a device data environment and then executes the construct on that device. It also specifies that loop iterations will be shared among the master threads of all thread teams in a league created by a teams construct. This pragma only applies to Intel® MIC Architecture.
omp target teams distribute parallel for	Creates a device data environment and then executes the construct on that device. It also specifies a loop that can be executed in parallel by multiple threads that are members of multiple teams created by a teams construct. This pragma only applies to Intel® MIC Architecture.
omp target teams distribute parallel for simd	Creates a device data environment and then executes the construct on that device. It also specifies a loop that can be executed in parallel by multiple threads that are members of multiple teams created by a teams construct. The loop will be distributed across the teams, which will be executed concurrently using SIMD instructions. This pragma only applies to Intel® MIC Architecture.
omp target teams distribute simd	Creates a device data environment and then executes the construct on that device. It also specifies that loop iterations will be shared among the master threads of all thread teams in a league created by a teams construct. It will be executed concurrently using SIMD instructions. This pragma only applies to Intel® MIC Architecture.
omp teams distribute	Creates a league of thread teams to execute the structured block in the master thread of each team. It also specifies that loop iterations will be shared among the master threads of all thread teams in a league created by a teams construct.
omp teams distribute parallel for	Creates a league of thread teams to execute a structured block in the master thread of each team. It also specifies a loop that can be executed in parallel by multiple threads that are members of multiple teams.
omp teams distribute parallel for simd	Creates a league of thread teams to execute a structured block in the master thread of each team. It also specifies a loop that can be executed in parallel by multiple threads that are members of multiple teams. The loop will be distributed across the master threads of the teams region, which will be executed concurrently using SIMD instructions.
omp teams distribute simd	Creates a league of thread teams to execute the structured block in the master thread of each team. It also specifies a loop that will be distributed across the master threads of the teams.