B.6  Version 3.1 to 4.0 Differences

• Various changes throughout the specification were made to provide initial support of Fortran 2003 (see Section 1.7).
• C/C++ array syntax was extended to support array sections (see Section 3.2.5).
• The reduction clause (see Section 5.5.8) was extended and the declare reduction construct (see Section 5.5.11) was added to support user defined reductions.
• The proc_bind clause (see Section 10.1.3), the OMP_PLACES environment variable (see Section 21.1.6), and the omp_get_proc_bind runtime routine (see Section 18.3.1) were added to support thread affinity policies.
• SIMD directives were added to support SIMD parallelism (see Section 10.4).
• Implementation defined task scheduling points for untied tasks were removed (see Section 12.9).
• Device directives (see Chapter 13), the OMP_DEFAULT_DEVICE environment variable (see Section 21.2.7), and the omp_set_default_device, omp_get_default_device, omp_get_num_devices, omp_get_num_teams, omp_get_team_num, and omp_is_initial_device routines were added to support execution on devices.
• The taskgroup construct (see Section 15.4) was added to support deep task synchronization.
• The atomic construct (see Section 15.8.4) was extended to support atomic swap with the capture clause, to allow new atomic update and capture forms, and to support sequentially consistent atomic operations with a new seq_cst clause.
• The depend clause (see Section 15.9.5) was added to support task dependences.
• The cancel construct (see Section 16.1), the cancellation point construct (see Section 16.2), the omp_get_cancellation runtime routine (see Section 18.2.8), and the OMP_CANCELLATION environment variable (see Section 21.2.6) were added to support the concept of cancellation.
• The OMP_DISPLAY_ENV environment variable (see Section 21.7) was added to display the value of ICVs associated with the OpenMP environment variables.
• Examples (previously Appendix A) were moved to a separate document.