B.4  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 on page 83).
• C/C++ array syntax was extended to support array sections (see Section 2.1.5 on page 118).
• The proc_bind clause (see Section 2.6.2 on page 227), the OMP_PLACES environment variable (see Section 6.5 on page 1655), and the omp_get_proc_bind runtime routine (see Section 3.2.23 on page 1088) were added to support thread affinity policies.
• SIMD directives were added to support SIMD parallelism (see Section 2.9.3 on page 316).
• Implementation defined task scheduling points for untied tasks were removed (see Section 2.10.6 on page 415).
• Device directives (see Section 2.12 on page 448), the OMP_DEFAULT_DEVICE environment variable (see Section 6.15 on page 1677), 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 2.17.6 on page 648) was added to support more flexible deep task synchronization.
• The atomic construct (see Section 2.17.7 on page 652) 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 2.17.11 on page 736) was added to support task dependences.
• The cancel construct (see Section 2.18.1 on page 752), the cancellation point construct (see Section 2.18.2 on page 766), the omp_get_cancellation runtime routine (see Section 3.2.9 on page 1049) and the OMP_CANCELLATION environment variable (see Section 6.11 on page 1668) were added to support the concept of cancellation.
• The reduction clause (see Section 2.19.5.4 on page 885) was extended and the declare reduction construct (see Section 2.19.5.7 on page 902) was added to support user defined reductions.
• The OMP_DISPLAY_ENV environment variable (see Section 6.12 on page 1670) was added to display the value of ICVs associated with the OpenMP environment variables.
• Examples (previously Appendix A) were moved to a separate document.