v4.2.3

Synopsis

• Performance optimizations in the symbolic layer and generated code for x86, GPU and MPI.
• Various minor correctness and performance bug fixes.
• Improvements to application developer API.
• Added new tutorial notebooks.
• Increased test coverage - particularly for MPI and GPU's.

Backwards compatibility breaks and deprecations

None

Changes

• Restrict pytest to < 6.0 @rhodrin (#1411)
• pip prod(deps): update distributed requirement from <2.20 to <2.22 @dependabot (#1402)
• MPI minor bug fixes @rhodrin (#1408)
• mac notebook fix @rhodrin (#1407)
• Run docker test @mloubout (#1398)
• docker: fix typos @mloubout (#1397)
• compiler: version checks avoid unreliable exception @dbowman-ion (#1386)
• Fix cross-loop blocking with imperfect nests @FabioLuporini (#1381)
• Cancel previous CI at new commit @mloubout (#1378)
• Heapification of temporaries @FabioLuporini (#1349)
• Fix missing halo exchange over invariants fields @FabioLuporini (#1359)
• tutorials: 00_index fix broken link @georgebisbas (#1356)
• CI: add autolog of PRs @mloubout (#1338)

🐛 Bug Fixes

• Fix issue #1298 @FabioLuporini (#1421)
• ir: Fix lowering of ConditionalDimension @FabioLuporini (#1419)
• mpi: Patch compute_loc_indices + test @FabioLuporini (#1416)
• Fix estimate_cost @FabioLuporini (#1405)
• Fix issue 1332 (fablup version) @FabioLuporini (#1389)
• checkpointing: set right size_ckp @ofmla (#1361)
• Data tweaks @rhodrin (#1369)
• Fix min storage @FabioLuporini (#1372)
• Avoid dererencing dangling pointers on GC'd objects @tjb900 (#1316)
• Replace subdimension in expressions @mloubout (#1345)
• Indexify with non-symbolic numeric indices @mloubout (#1343)
• Fix numeric indices @mloubout (#1341)

API

• Buffer: remove unused from args to allow multi buffers @mloubout (#1420)
• operator: Expose more opt knobs to the user level @FabioLuporini (#1387)
• Function/Expr shift utility @mloubout (#1377)
• Prevent sympy cache blowup @mloubout (#1366)
• Symbolic speedup @mloubout (#1362)

Examples

• examples: fix issue #1393 @ofmla (#1400)
• tutorials: add missing ignore tag in dask tutorial @mloubout (#1403)
• Dask tutorial with operator created only once @ofmla (#945)
• tests: Fix args and test viscoacoustic @georgebisbas (#1365)
• Add norm asserts for ssa iso notebooks @jkwashbourne (#1373)
• Make dt a solve property to use latest model parameters @mloubout (#1371)
• examples: Drop unnecessary NBVALs @FabioLuporini (#1367)
• Refine CFL condition in seismic @mloubout (#1348)
• Freesurface with subdomain (iso-acoustic) @mloubout (#1344)
• Improve solve speed for complicated equations @mloubout (#1342)
• elastic-fix @mloubout (#1339)

Documentation

• tutos: Inception of performance modes notebook @georgebisbas (#1358)
• Fix issue 1185 @dabiged (#1360)
• ConditionalDimensions notebook @georgebisbas (#1269)
• Add binder directory with requirements.txt including matplotlib @jkwashbourne (#1351)

MPI

• ci: Test all critical seismic examples with MPI @FabioLuporini (#1418)
• Single precision interpolation @mloubout (#1413)
• Update halo warning @rhodrin (#1370)
• Fix MPI benchmark json results @jaimesouza (#1295)
• Improve detection of redundant halo exchanges @FabioLuporini (#1352)

GPU

• Add MPI+GPU runs to CI @georgebisbas (#1251)
• Tweak CIRE for GPUs @FabioLuporini (#1409)
• Add docker publish @mloubout (#1388)
• Nvidia dockerfile @FabioLuporini (#1392)
• Tool get_gpu_info (using lshw, lspci) with test @jack-lascala (#1383)

Contributors

Many thanks to all the contributors to this release (last surname alphabetical order):

• George Bisbas (Imperial College London)
• David Bowman (ION)
• Tim Burgess (DUG)
• Jaime Freire de Souza
• Chris Dinneen
• Ken Hester (NVidia)
• Navjot Kukreja (Imperial College London)
• Giacomo La Scala
• Mathias Louboutin (Georgia Institute of Technology)
• Fabio Luporini (Devito Codes)
• Oscar Mojica (SENAI CIMATEC)
• Rhodri Nelson (Imperial College London)
• John Washbourne (Chevron)