Internals: Refactor MT scheduling (#8012)

Browse Source

Prep for fixing test added in #7913.

This is a large scale no functional change refactor, however, MT output
is perturbed as tied scores will be broken differently due to ordering
changes (still deterministic).

Split multi-threaded scheduling out of the monolithic
V3OrderParallel.cpp, into relatively independent parts, simplify the
data structures, and drop redundant or unused code.

New translation units:
- V3OrderMTaskGraph.h/.cpp: OrderMTaskGraph, the graph of LogicMTask
  vertices and MTaskEdge edges. LogicMTask and MTaskEdge no longer
  depend on the coarsening algorithm's merge candidate types;
  per-algorithm auxiliary data is attached externally via the vertex and
  edge user pointers.
- V3OrderMTaskFixHazards.cpp: data hazard fixup, was FixDataHazards.
- V3OrderMTaskContraction.cpp: graph coarsening, was Partitioner
  together with PropagateCp and the merge candidate types.
- V3OrderParallel.cpp: now just the partitioning driver and ExecMTask
  graph construction.

Data structure changes:
- Delete V3Scoreboard.h/.cpp. The generic template had a single user, now
  a file-local MergeCandidateScoreboard in V3OrderMTaskContraction.cpp.
- Merge candidates are now MergeCandidate/SiblingMC/EdgeMC, distinguished
  by a bit in the candidate id rather than by a vtable, and allocated by
  the scoreboard, which owns their lifetime. This removes the multiple
  inheritance previously used by MTaskEdge.

Move `hashGraphDebug` which prints the hash of a graph's shape for debugging
to generic `V3Graph::hashGraphDebug`.

Removed (can be added back later):
- Unnecesasry self tests that force special data stucture requirements.
- Per stage --stats output under --debug. (Final figures still reported.)
- Various debug dumps

...

This commit is contained in:

Geza Lore

2026-07-31 15:03:26 +01:00

committed by GitHub

parent 40323cc02c

commit 781f6d90bf

19 changed files with 2400 additions and 2597 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download Patch File Download Diff File Expand all files Collapse all files

src/V3OrderParallel.cpp

+85 -2335

File diff suppressed because it is too large Load Diff