5.11. Graphcore Communication Library (GCL)

3.0.0

New features

  • The GCL option syncful.useForwardingToSupportStridedGroups=auto is now exposed externally.

    By doing through-routing over intermediate replicas, sliding window reachability is extended for certain configurations. For a replica size equal to 1, this option avoids deadlocks.

Bug Fixes

  • The broadcast method is no longer selected when the stride is greater than 1.

  • Three-phase collective operations are now scheduled properly for consecutive communication groups that span multiple glossary:ILDs.

Other improvements

  • The GCL documentation has been updated and split out into a separate document: GCL User Guide and API Reference. More detail on collective operations and logical topologies has been added.

  • Added getters to the public API.

Known issues

None

Compatibility changes

  • Removed the useSynclessCollectives option from the public API. The option was deprecated in SDK 2.6 and has now been removed.

  • Renamed libgcl_ct.so to libgcl.so. The GCL shared library was renamed which means that programs directly linking with GCL need to pass the -lgcl flag to the linker instead of -lgcl_ct.