BE-265: HashQL: Make CopyPropagation aware of local re-assignments

[indietyp]

🌟 What is the purpose of this PR?

Enhance the Place::local function to be more efficient by making it a const fn that doesn't require an interner parameter, and add a convenient From<Local> implementation for Operand to simplify code that converts locals to operands.

🔍 What does this change?

• Make Place::local() a const fn that doesn't require an interner parameter
• Add From<Local> implementation for Operand to simplify code
• Update all call sites to use the new signature
• Enhance copy propagation to handle both constant and local value propagation
• Add tests for copy propagation with local values

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?

• Added new tests for copy propagation with local values
• Existing tests continue to pass with the updated API

[cursor]

PR Summary

Modernizes constructor APIs and broadens MIR optimizations.

• Make Place::local() and Target::block() const and remove interner args; switch to Interned::empty() and update all usages (reify, builders, passes, docs/examples)
• Add From<Local> for Operand to simplify local-to-operand conversion
• Enhance copy propagation to track and substitute both constants and locals (KnownValue), including block-param consensus; update visitor logic accordingly
• Adjust CFG simplify simplify_goto signature (drops context param) and update call site
• Update data-dependency resolution and SSA/administrative reduction to new Place::local usage
• Add and snapshot new tests for copy propagation of locals and chains (simple_copy, copy_chain, block-param variants)

^{Written by Cursor Bugbot for commit bee6b36. This will update automatically on new commits. Configure here.}

[indietyp]

• BE-273: HashQL: Profile and benchmark MIR interpreter #8251
• BE-272: HashQL: Add numeric addition and subtraction operators to MIR #8250
• BE-257: HashQL: Implement MIR interpreter with runtime value representation #8245
• BE-271: HashQL: Implement PostInline pass #8240
• BE-269: HashQL: Move PreInline out into Canonicalization pass #8239
• BE-268: HashQL: Rename PreInlining to PreInline for consistency #8238
• BE-270: HashQL: Optimize empty tuples to unit constants in MIR #8237
• BE-197: Implement MIR inline pass for HashQL #8236
• BE-267: Use bump scopes instead of full resets across transformation passes #8234
• BE-266: HashQL: Implement PreInlining pass for MIR optimization #8233
• BE-265: HashQL: Make CopyPropagation aware of local re-assignments #8231 👈 (View in Graphite)
• BE-264: HashQL: Rename SROA to ForwardSubstitution for better semantic clarity #8230
• BE-263: HashQL: add body! macro for declarative MIR construction in tests #8229
• BE-261: HashQL: Implement Administrative Reduction pass for MIR #8227
• BE-262: HashQL: Do not intern empty slices #8223
• BE-260: HashQL: Switch to bump allocator with scoping support #8218
• BE-259: HashQL: Add benchmarks for type system operations #8216
• BE-227: HashQL: Implement call graph analysis for MIR #8214
• BE-258: HashQL: Add Changed enum to track MIR transformation pass modifications #8210
• BE-255: HashQL: Implement Copy Propagation (CP) pass for MIR #8207
• BE-231: HashQL: Add InstSimplify pass for MIR instruction simplification and constant folding #8206
• BE-254: Add CodSpeed benchmarking for HashQL MIR transformation passes #8204
• main

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[codspeed-hq]

Merging this PR will not alter performance

✅ 17 untouched benchmarks

---

_{Comparing bm/be-265-hashql-track-locals-inside-of-copy-propagation (bee6b36) with main (ef9788b)}

[codecov]

Codecov Report

❌ Patch coverage is 96.42857% with 4 lines in your changes missing coverage. Please review.
✅ Project coverage is 80.94%. Comparing base (b51e5cd) to head (719edd0).

Files with missing lines	Patch %	Lines
libs/@local/hashql/mir/src/body/operand.rs	0.00%	3 Missing ⚠️
libs/@local/hashql/mir/src/reify/rvalue.rs	50.00%	1 Missing ⚠️

Additional details and impacted files

@@                                   Coverage Diff                                    @@
##           bm/be-264-hashql-rename-sroa-to-projectionforwarding    #8231      +/-   ##
========================================================================================
+ Coverage                                                 80.77%   80.94%   +0.17%     
========================================================================================
  Files                                                        81       81              
  Lines                                                     10527    10575      +48     
  Branches                                                    282      276       -6     
========================================================================================
+ Hits                                                       8503     8560      +57     
+ Misses                                                     1914     1907       -7     
+ Partials                                                    110      108       -2     

Flag	Coverage Δ
rust.hashql-compiletest	46.65% <ø> (ø)
rust.hashql-mir	87.39% <96.42%> (+0.17%)	⬆️

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[augmentcode]

🤖 Augment PR Summary

Summary: Extends HashQL MIR copy propagation to handle local-to-local copies (not just constants) and simplifies MIR place/operand helpers.

Changes:

• Place::local(Local) is now a const fn and no longer needs an Interner; it uses a canonical empty projection list.
• Adds From<Local> for Operand to streamline local-to-operand conversions.
• Updates call sites across MIR builder, reifier, SSA repair, CFG simplify, and data-dependency resolution to the new Place::local signature.
• Generalizes CopyPropagation to track a KnownValue (constant or local) and substitute operands, including via block-parameter agreement.
• Adds new unit tests + snapshots for simple copy, chained copy, and block-param copy/disagreement scenarios.

Technical Notes: The pass remains single-pass (reverse postorder), does not traverse projections, and assumes SSA-like single-assignment locals for soundness.

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[augmentcode]

Review completed. 1 suggestions posted.

Comment augment review to trigger a new review at any time.

[graphite-app]

Merge activity

• Jan 17, 4:38 PM UTC: Graphite rebased this pull request, because this pull request is set to merge when ready.