BE-303: HashQL: Split MIR basic blocks by target support

[indietyp]

🌟 What is the purpose of this PR?

Introduce a MIR execution-analysis pass that splits basic blocks into contiguous regions with uniform target support, returning per-block target affinities for downstream scheduling.

🔍 What does this change?

• Add a basic-block splitting pass that remaps block IDs, inserts Goto chains between split regions, and returns target affinities.
• Add unit and snapshot coverage for splitting behavior and cost remapping.
• Extend execution-analysis data structures to support target bitsets/arrays and cost remapping.

Pre-Merge Checklist 🚀

🚢 Has this modified a publishable library?

This PR:

• does not modify any publishable blocks or libraries, or modifications do not need publishing

📜 Does this require a change to the docs?

The changes in this PR:

• are internal and do not require a docs change

🕸️ Does this require a change to the Turbo Graph?

The changes in this PR:

• do not affect the execution graph

🛡 What tests cover this?

• New unit tests and snapshot coverage for the splitting pass.

❓ How to test this?

• Run the hashql-mir test suite that includes execution spli

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[cursor]

PR Summary

Medium Risk
Touches core MIR CFG structure and target ID representation, so incorrect remapping or edge cases in splitting could miswire control flow or misattribute costs; coverage is strong via new unit/snapshot tests.

Overview
Adds a new MIR execution-analysis pass (execution::splitting) that splits BasicBlocks into contiguous regions where all statements share the same supported target set, remaps all BasicBlockId references, and inserts Goto chains to preserve control flow while returning per-block target affinities.

To support this, core ID utilities are extended with a new fixed-size IdArray (typed-ID indexing over [T; N]) and a reworked FiniteBitSet (typed-ID, single-integer bitset with range ops/iter), and MIR’s target identifiers are refactored from a newtype into a TargetId enum with Id impl plus TargetArray/TargetBitSet aliases; StatementCostVec gains offset recomputation (remap) and block-scoped accessors. Extensive unit + snapshot tests validate splitting behavior, ID remapping, and cost remapping.

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[github-actions]

Benchmark results

@rust/hash-graph-benches – Integrations

policy_resolution_large

Function	Value	Mean	Flame graphs
resolve_policies_for_actor	user: empty, selectivity: high, policies: 2002	$$27.0 \mathrm{ms} \pm 162 \mathrm{μs}\left({\color{lightgreen}-6.990 \mathrm{\%}}\right) $$	Flame Graph
resolve_policies_for_actor	user: empty, selectivity: low, policies: 1	$$3.23 \mathrm{ms} \pm 14.5 \mathrm{μs}\left({\color{lightgreen}-6.280 \mathrm{\%}}\right) $$	Flame Graph
resolve_policies_for_actor	user: empty, selectivity: medium, policies: 1001	$$12.1 \mathrm{ms} \pm 90.4 \mathrm{μs}\left({\color{lightgreen}-13.022 \mathrm{\%}}\right) $$	Flame Graph
resolve_policies_for_actor	user: seeded, selectivity: high, policies: 3314	$$43.3 \mathrm{ms} \pm 288 \mathrm{μs}\left({\color{gray}-1.581 \mathrm{\%}}\right) $$	Flame Graph
resolve_policies_for_actor	user: seeded, selectivity: low, policies: 1	$$14.5 \mathrm{ms} \pm 102 \mathrm{μs}\left({\color{gray}-2.157 \mathrm{\%}}\right) $$	Flame Graph
resolve_policies_for_actor	user: seeded, selectivity: medium, policies: 1526	$$25.0 \mathrm{ms} \pm 173 \mathrm{μs}\left({\color{gray}0.289 \mathrm{\%}}\right) $$	Flame Graph
resolve_policies_for_actor	user: system, selectivity: high, policies: 2078	$$44.6 \mathrm{ms} \pm 189 \mathrm{μs}\left({\color{gray}0.123 \mathrm{\%}}\right) $$	Flame Graph
resolve_policies_for_actor	user: system, selectivity: low, policies: 1	$$20.9 \mathrm{ms} \pm 127 \mathrm{μs}\left({\color{gray}0.688 \mathrm{\%}}\right) $$	Flame Graph
resolve_policies_for_actor	user: system, selectivity: medium, policies: 1033	$$29.7 \mathrm{ms} \pm 257 \mathrm{μs}\left({\color{gray}1.53 \mathrm{\%}}\right) $$	Flame Graph

policy_resolution_medium

Function	Value	Mean	Flame graphs
resolve_policies_for_actor	user: empty, selectivity: high, policies: 102	$$3.71 \mathrm{ms} \pm 23.3 \mathrm{μs}\left({\color{gray}0.221 \mathrm{\%}}\right) $$	Flame Graph
resolve_policies_for_actor	user: empty, selectivity: low, policies: 1	$$2.96 \mathrm{ms} \pm 15.7 \mathrm{μs}\left({\color{gray}3.28 \mathrm{\%}}\right) $$	Flame Graph
resolve_policies_for_actor	user: empty, selectivity: medium, policies: 51	$$3.23 \mathrm{ms} \pm 17.0 \mathrm{μs}\left({\color{gray}-1.463 \mathrm{\%}}\right) $$	Flame Graph
resolve_policies_for_actor	user: seeded, selectivity: high, policies: 269	$$5.05 \mathrm{ms} \pm 29.0 \mathrm{μs}\left({\color{gray}-0.804 \mathrm{\%}}\right) $$	Flame Graph
resolve_policies_for_actor	user: seeded, selectivity: low, policies: 1	$$3.43 \mathrm{ms} \pm 19.4 \mathrm{μs}\left({\color{gray}-0.711 \mathrm{\%}}\right) $$	Flame Graph
resolve_policies_for_actor	user: seeded, selectivity: medium, policies: 107	$$3.97 \mathrm{ms} \pm 20.2 \mathrm{μs}\left({\color{gray}-1.276 \mathrm{\%}}\right) $$	Flame Graph
resolve_policies_for_actor	user: system, selectivity: high, policies: 133	$$4.20 \mathrm{ms} \pm 31.4 \mathrm{μs}\left({\color{gray}-0.248 \mathrm{\%}}\right) $$	Flame Graph
resolve_policies_for_actor	user: system, selectivity: low, policies: 1	$$3.26 \mathrm{ms} \pm 15.3 \mathrm{μs}\left({\color{gray}-1.922 \mathrm{\%}}\right) $$	Flame Graph
resolve_policies_for_actor	user: system, selectivity: medium, policies: 63	$$3.92 \mathrm{ms} \pm 22.4 \mathrm{μs}\left({\color{gray}-0.530 \mathrm{\%}}\right) $$	Flame Graph

policy_resolution_none

Function	Value	Mean	Flame graphs
resolve_policies_for_actor	user: empty, selectivity: high, policies: 2	$$2.39 \mathrm{ms} \pm 12.5 \mathrm{μs}\left({\color{gray}-1.789 \mathrm{\%}}\right) $$	Flame Graph
resolve_policies_for_actor	user: empty, selectivity: low, policies: 1	$$2.36 \mathrm{ms} \pm 17.0 \mathrm{μs}\left({\color{gray}-3.649 \mathrm{\%}}\right) $$	Flame Graph
resolve_policies_for_actor	user: empty, selectivity: medium, policies: 1	$$2.44 \mathrm{ms} \pm 15.3 \mathrm{μs}\left({\color{gray}-1.045 \mathrm{\%}}\right) $$	Flame Graph
resolve_policies_for_actor	user: system, selectivity: high, policies: 8	$$2.68 \mathrm{ms} \pm 13.0 \mathrm{μs}\left({\color{gray}-0.516 \mathrm{\%}}\right) $$	Flame Graph
resolve_policies_for_actor	user: system, selectivity: low, policies: 1	$$2.51 \mathrm{ms} \pm 10.9 \mathrm{μs}\left({\color{gray}-2.148 \mathrm{\%}}\right) $$	Flame Graph
resolve_policies_for_actor	user: system, selectivity: medium, policies: 3	$$2.75 \mathrm{ms} \pm 14.1 \mathrm{μs}\left({\color{gray}-0.261 \mathrm{\%}}\right) $$	Flame Graph

policy_resolution_small

Function	Value	Mean	Flame graphs
resolve_policies_for_actor	user: empty, selectivity: high, policies: 52	$$2.85 \mathrm{ms} \pm 12.0 \mathrm{μs}\left({\color{gray}2.23 \mathrm{\%}}\right) $$	Flame Graph
resolve_policies_for_actor	user: empty, selectivity: low, policies: 1	$$2.54 \mathrm{ms} \pm 18.7 \mathrm{μs}\left({\color{gray}3.93 \mathrm{\%}}\right) $$	Flame Graph
resolve_policies_for_actor	user: empty, selectivity: medium, policies: 25	$$2.66 \mathrm{ms} \pm 14.9 \mathrm{μs}\left({\color{gray}0.460 \mathrm{\%}}\right) $$	Flame Graph
resolve_policies_for_actor	user: seeded, selectivity: high, policies: 94	$$3.17 \mathrm{ms} \pm 14.0 \mathrm{μs}\left({\color{gray}1.32 \mathrm{\%}}\right) $$	Flame Graph
resolve_policies_for_actor	user: seeded, selectivity: low, policies: 1	$$2.72 \mathrm{ms} \pm 14.1 \mathrm{μs}\left({\color{gray}1.12 \mathrm{\%}}\right) $$	Flame Graph
resolve_policies_for_actor	user: seeded, selectivity: medium, policies: 26	$$2.95 \mathrm{ms} \pm 13.2 \mathrm{μs}\left({\color{gray}1.66 \mathrm{\%}}\right) $$	Flame Graph
resolve_policies_for_actor	user: system, selectivity: high, policies: 66	$$3.17 \mathrm{ms} \pm 20.8 \mathrm{μs}\left({\color{gray}4.26 \mathrm{\%}}\right) $$	Flame Graph
resolve_policies_for_actor	user: system, selectivity: low, policies: 1	$$2.67 \mathrm{ms} \pm 13.0 \mathrm{μs}\left({\color{gray}1.35 \mathrm{\%}}\right) $$	Flame Graph
resolve_policies_for_actor	user: system, selectivity: medium, policies: 29	$$2.95 \mathrm{ms} \pm 21.3 \mathrm{μs}\left({\color{gray}3.04 \mathrm{\%}}\right) $$	Flame Graph

read_scaling_complete

Function	Value	Mean	Flame graphs
entity_by_id;one_depth	1 entities	$$42.1 \mathrm{ms} \pm 309 \mathrm{μs}\left({\color{gray}3.73 \mathrm{\%}}\right) $$	Flame Graph
entity_by_id;one_depth	10 entities	$$75.8 \mathrm{ms} \pm 452 \mathrm{μs}\left({\color{gray}-2.945 \mathrm{\%}}\right) $$	Flame Graph
entity_by_id;one_depth	25 entities	$$43.3 \mathrm{ms} \pm 212 \mathrm{μs}\left({\color{gray}-3.907 \mathrm{\%}}\right) $$	Flame Graph
entity_by_id;one_depth	5 entities	$$46.3 \mathrm{ms} \pm 259 \mathrm{μs}\left({\color{gray}-0.997 \mathrm{\%}}\right) $$	Flame Graph
entity_by_id;one_depth	50 entities	$$54.8 \mathrm{ms} \pm 332 \mathrm{μs}\left({\color{gray}0.844 \mathrm{\%}}\right) $$	Flame Graph
entity_by_id;two_depth	1 entities	$$42.6 \mathrm{ms} \pm 273 \mathrm{μs}\left({\color{gray}2.42 \mathrm{\%}}\right) $$	Flame Graph
entity_by_id;two_depth	10 entities	$$414 \mathrm{ms} \pm 936 \mathrm{μs}\left({\color{gray}-1.801 \mathrm{\%}}\right) $$	Flame Graph
entity_by_id;two_depth	25 entities	$$96.2 \mathrm{ms} \pm 577 \mathrm{μs}\left({\color{gray}-2.868 \mathrm{\%}}\right) $$	Flame Graph
entity_by_id;two_depth	5 entities	$$87.4 \mathrm{ms} \pm 413 \mathrm{μs}\left({\color{gray}1.64 \mathrm{\%}}\right) $$	Flame Graph
entity_by_id;two_depth	50 entities	$$320 \mathrm{ms} \pm 927 \mathrm{μs}\left({\color{red}13.1 \mathrm{\%}}\right) $$	Flame Graph
entity_by_id;zero_depth	1 entities	$$14.7 \mathrm{ms} \pm 69.4 \mathrm{μs}\left({\color{gray}-0.289 \mathrm{\%}}\right) $$	Flame Graph
entity_by_id;zero_depth	10 entities	$$14.6 \mathrm{ms} \pm 84.1 \mathrm{μs}\left({\color{gray}-2.335 \mathrm{\%}}\right) $$	Flame Graph
entity_by_id;zero_depth	25 entities	$$14.9 \mathrm{ms} \pm 79.7 \mathrm{μs}\left({\color{gray}-1.365 \mathrm{\%}}\right) $$	Flame Graph
entity_by_id;zero_depth	5 entities	$$14.7 \mathrm{ms} \pm 74.7 \mathrm{μs}\left({\color{gray}-1.644 \mathrm{\%}}\right) $$	Flame Graph
entity_by_id;zero_depth	50 entities	$$17.5 \mathrm{ms} \pm 85.1 \mathrm{μs}\left({\color{gray}-2.583 \mathrm{\%}}\right) $$	Flame Graph

read_scaling_linkless

Function	Value	Mean	Flame graphs
entity_by_id	1 entities	$$15.3 \mathrm{ms} \pm 98.8 \mathrm{μs}\left({\color{gray}3.61 \mathrm{\%}}\right) $$	Flame Graph
entity_by_id	10 entities	$$14.9 \mathrm{ms} \pm 73.7 \mathrm{μs}\left({\color{gray}0.710 \mathrm{\%}}\right) $$	Flame Graph
entity_by_id	100 entities	$$14.8 \mathrm{ms} \pm 76.2 \mathrm{μs}\left({\color{gray}1.62 \mathrm{\%}}\right) $$	Flame Graph
entity_by_id	1000 entities	$$15.2 \mathrm{ms} \pm 97.6 \mathrm{μs}\left({\color{gray}1.07 \mathrm{\%}}\right) $$	Flame Graph
entity_by_id	10000 entities	$$22.0 \mathrm{ms} \pm 159 \mathrm{μs}\left({\color{gray}-1.158 \mathrm{\%}}\right) $$	Flame Graph

representative_read_entity

Function	Value	Mean	Flame graphs
entity_by_id	entity type ID: https://blockprotocol.org/@alice/types/entity-type/block/v/1	$$29.4 \mathrm{ms} \pm 300 \mathrm{μs}\left({\color{gray}-2.643 \mathrm{\%}}\right) $$	Flame Graph
entity_by_id	entity type ID: https://blockprotocol.org/@alice/types/entity-type/book/v/1	$$30.3 \mathrm{ms} \pm 301 \mathrm{μs}\left({\color{gray}1.76 \mathrm{\%}}\right) $$	Flame Graph
entity_by_id	entity type ID: https://blockprotocol.org/@alice/types/entity-type/building/v/1	$$31.3 \mathrm{ms} \pm 279 \mathrm{μs}\left({\color{gray}3.81 \mathrm{\%}}\right) $$	Flame Graph
entity_by_id	entity type ID: https://blockprotocol.org/@alice/types/entity-type/organization/v/1	$$31.0 \mathrm{ms} \pm 322 \mathrm{μs}\left({\color{gray}3.99 \mathrm{\%}}\right) $$	Flame Graph
entity_by_id	entity type ID: https://blockprotocol.org/@alice/types/entity-type/page/v/2	$$30.2 \mathrm{ms} \pm 331 \mathrm{μs}\left({\color{gray}2.65 \mathrm{\%}}\right) $$	Flame Graph
entity_by_id	entity type ID: https://blockprotocol.org/@alice/types/entity-type/person/v/1	$$30.8 \mathrm{ms} \pm 269 \mathrm{μs}\left({\color{gray}4.19 \mathrm{\%}}\right) $$	Flame Graph
entity_by_id	entity type ID: https://blockprotocol.org/@alice/types/entity-type/playlist/v/1	$$30.8 \mathrm{ms} \pm 324 \mathrm{μs}\left({\color{gray}4.19 \mathrm{\%}}\right) $$	Flame Graph
entity_by_id	entity type ID: https://blockprotocol.org/@alice/types/entity-type/song/v/1	$$30.5 \mathrm{ms} \pm 292 \mathrm{μs}\left({\color{gray}1.83 \mathrm{\%}}\right) $$	Flame Graph
entity_by_id	entity type ID: https://blockprotocol.org/@alice/types/entity-type/uk-address/v/1	$$29.6 \mathrm{ms} \pm 298 \mathrm{μs}\left({\color{gray}-1.374 \mathrm{\%}}\right) $$	Flame Graph

representative_read_entity_type

Function	Value	Mean	Flame graphs
get_entity_type_by_id	Account ID: bf5a9ef5-dc3b-43cf-a291-6210c0321eba	$$8.18 \mathrm{ms} \pm 38.3 \mathrm{μs}\left({\color{gray}1.47 \mathrm{\%}}\right) $$	Flame Graph

representative_read_multiple_entities

Function	Value	Mean	Flame graphs
entity_by_property	traversal_paths=0	0	$$46.8 \mathrm{ms} \pm 270 \mathrm{μs}\left({\color{gray}0.668 \mathrm{\%}}\right) $$
entity_by_property	traversal_paths=255	1,resolve_depths=inherit:1;values:255;properties:255;links:127;link_dests:126;type:true	$$93.9 \mathrm{ms} \pm 423 \mathrm{μs}\left({\color{gray}-4.761 \mathrm{\%}}\right) $$
entity_by_property	traversal_paths=2	1,resolve_depths=inherit:0;values:0;properties:0;links:0;link_dests:0;type:false	$$51.6 \mathrm{ms} \pm 316 \mathrm{μs}\left({\color{lightgreen}-6.408 \mathrm{\%}}\right) $$
entity_by_property	traversal_paths=2	1,resolve_depths=inherit:0;values:0;properties:0;links:1;link_dests:0;type:true	$$59.3 \mathrm{ms} \pm 310 \mathrm{μs}\left({\color{lightgreen}-5.188 \mathrm{\%}}\right) $$
entity_by_property	traversal_paths=2	1,resolve_depths=inherit:0;values:0;properties:2;links:1;link_dests:0;type:true	$$67.7 \mathrm{ms} \pm 412 \mathrm{μs}\left({\color{lightgreen}-5.362 \mathrm{\%}}\right) $$
entity_by_property	traversal_paths=2	1,resolve_depths=inherit:0;values:2;properties:2;links:1;link_dests:0;type:true	$$73.0 \mathrm{ms} \pm 340 \mathrm{μs}\left({\color{lightgreen}-6.993 \mathrm{\%}}\right) $$
link_by_source_by_property	traversal_paths=0	0	$$50.7 \mathrm{ms} \pm 245 \mathrm{μs}\left({\color{gray}-2.387 \mathrm{\%}}\right) $$
link_by_source_by_property	traversal_paths=255	1,resolve_depths=inherit:1;values:255;properties:255;links:127;link_dests:126;type:true	$$79.6 \mathrm{ms} \pm 387 \mathrm{μs}\left({\color{gray}1.97 \mathrm{\%}}\right) $$
link_by_source_by_property	traversal_paths=2	1,resolve_depths=inherit:0;values:0;properties:0;links:0;link_dests:0;type:false	$$58.3 \mathrm{ms} \pm 368 \mathrm{μs}\left({\color{gray}-1.231 \mathrm{\%}}\right) $$
link_by_source_by_property	traversal_paths=2	1,resolve_depths=inherit:0;values:0;properties:0;links:1;link_dests:0;type:true	$$67.0 \mathrm{ms} \pm 407 \mathrm{μs}\left({\color{gray}0.563 \mathrm{\%}}\right) $$
link_by_source_by_property	traversal_paths=2	1,resolve_depths=inherit:0;values:0;properties:2;links:1;link_dests:0;type:true	$$70.7 \mathrm{ms} \pm 474 \mathrm{μs}\left({\color{gray}3.71 \mathrm{\%}}\right) $$
link_by_source_by_property	traversal_paths=2	1,resolve_depths=inherit:0;values:2;properties:2;links:1;link_dests:0;type:true	$$69.2 \mathrm{ms} \pm 328 \mathrm{μs}\left({\color{gray}2.66 \mathrm{\%}}\right) $$

scenarios

Function	Value	Mean	Flame graphs
full_test	query-limited	$$138 \mathrm{ms} \pm 627 \mathrm{μs}\left({\color{gray}3.02 \mathrm{\%}}\right) $$	Flame Graph
full_test	query-unlimited	$$135 \mathrm{ms} \pm 545 \mathrm{μs}\left({\color{gray}1.16 \mathrm{\%}}\right) $$	Flame Graph
linked_queries	query-limited	$$38.9 \mathrm{ms} \pm 271 \mathrm{μs}\left({\color{lightgreen}-62.290 \mathrm{\%}}\right) $$	Flame Graph
linked_queries	query-unlimited	$$574 \mathrm{ms} \pm 1.57 \mathrm{ms}\left({\color{lightgreen}-5.256 \mathrm{\%}}\right) $$	Flame Graph

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Your organization requires reapproval when changes are made, so Graphite has dismissed approvals. See the output of git range-diff at https://github.com/hashintel/hash/actions/runs/21756355661