perf(codegen): full-outline the class-field-GET diamond for oversized modules (#5391 path 2)

[proggeramlug]

What

Extends the #5334 lever-B full-outline from class-field SET to class-field GET: when full-outline is enabled (size-gated by PERRY_FULL_OUTLINE_IC), the class_field_get diamond (inline precheck + guard call + fast slot load + by-name fallback + phi) collapses to a single js_class_field_get_ic(...) call returning the field value.

Part of #5391 path 2 — shrinking large minified functions at their source so clang -O0 (whose per-function time is superlinear in size) can compile them.

Runtime helper

js_class_field_get_ic runs the same js_typed_feedback_class_field_get_guard; on a PASS reads the field slot as f64 (a plain number is self-boxing in nan-boxing, so raw-f64 and boxed slots read identically — matching the inline class_field_get.fast plain load double); on a MISS records the fallback and reads by name. The outline drops the inline path's static raw-number type hint (result treated as a general JS value), which is value-correct.

Validation

• New unit test full_outline_ic_collapses_class_field_get_to_single_call (both gate states).
• E2E: a class with field GET+SET runs to the correct result (5999997) with full-outline ON and OFF.
• Full perry-codegen suite green. Default off = unchanged behavior.
• On the cli.js bundle, this fired at 39,445 GET sites (alongside 115,454 SET), trimming IR 1.10GB → 1.02GB.

Scope note (honest)

This shrinks class-field-heavy functions. The bundle's largest functions, however, are dominated by a different construct — inline object/array literal construction (the 18MB perry_closure...31856 is ~17K js_gc_note_slot_layout + 11K js_inline_arena_slow_alloc + 9K js_write_barrier_slot: a giant data-table builder). Shrinking those needs literal-construction / inline-allocator outlining, a separate follow-up under #5391.

Refs #5391, #5334.

Summary by CodeRabbit

• Chores
  • Optimized class field property access performance through an enhanced inline cache implementation for specific runtime scenarios.
  • Added supporting infrastructure for fast-path property retrieval operations with verification tests.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: a42f7b36-ddea-4ba1-be22-611dc845dc96

📥 Commits

Reviewing files that changed from the base of the PR and between 7497483 and 47fa131.

📒 Files selected for processing (4)

• crates/perry-codegen/src/expr/property_get.rs
• crates/perry-codegen/src/runtime_decls/objects.rs
• crates/perry-codegen/tests/typed_feedback.rs
• crates/perry-runtime/src/typed_feedback/guards.rs

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📝 Walkthrough

Walkthrough

Adds a fully-outlined inline-cache path for class-field GET operations. A new js_class_field_get_ic extern-C function is introduced in the runtime, its ABI is declared in the codegen runtime declarations, and the PropertyGet class-field fast path conditionally emits a single call to it (bypassing the inline guard/phi diamond) when full_outline_ic_enabled() is true. A new test verifies both IR shapes.

Changes

Full-outline IC for class-field GET

Layer / File(s)	Summary
Runtime js_class_field_get_ic entry point and symbol retention crates/perry-runtime/src/typed_feedback/guards.rs	Adds #[no_mangle] pub extern "C" fn js_class_field_get_ic that runs the typed-feedback guard and either reads the cached f64 slot directly on PASS or falls back to js_object_get_field_by_name_f64 on FAIL. Adds G1E to the keep_guard_symbols retention block to prevent LTO/strip from removing the new symbol.
ABI declaration and PropertyGet codegen emission crates/perry-codegen/src/runtime_decls/objects.rs, crates/perry-codegen/src/expr/property_get.rs	Declares js_class_field_get_ic with its full DOUBLE-returning ABI signature in declare_phase_b_objects. In property_get.rs, adds a conditional branch in the class-field fast path that, when full_outline_ic_enabled() is true, computes key_raw and expected_keys and emits a single outlined IC call, returning immediately before the inline guard/precheck/phi logic.
IR-level test for outline vs inline GET paths crates/perry-codegen/tests/typed_feedback.rs	Adds full_outline_ic_collapses_class_field_get_to_single_call, which asserts that with PERRY_FULL_OUTLINE_IC=1 only js_class_field_get_ic appears in IR and the inline class_field_get.fast/fallback/guard are absent, and vice versa with PERRY_FULL_OUTLINE_IC=0.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Possibly related PRs

• PerryTS/perry#5198: Modifies the same class-field PropertyGet fast path in property_get.rs, establishing the inline typed-feedback shape-guard logic that this PR replaces under full_outline_ic_enabled.
• PerryTS/perry#5385: Implements the analogous fully-outlined IC path for class-field SET (js_class_field_set_ic) and introduces the full_outline_ic_enabled gating infrastructure that this PR's GET path depends on.

Poem

🐇 Hoppy news from the warren below,
A diamond of guards collapsed to one call,
js_class_field_get_ic takes the show —
One outlined IC to cover it all!
No more fast/fallback/phi to trace,
Just a single leap through cyberspace. 🌟

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly describes the main optimization: extending full-outline to class-field GET operations for oversized modules, with specific reference to the scope and related issue.
Description check	✅ Passed	The PR description is comprehensive and follows the template structure with What, Runtime helper, Validation, and Scope sections, though test plan checkboxes are incomplete.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch feat/full-outline-ic-get

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