constant-folding

name	constant-folding
description	Implement issue

Constant Folding

Use this skill to execute issue #140 with small, correctness-first compiler changes.

Workflow

1. Implement a dedicated function pass that folds compile-time constant expressions.
2. Reuse existing fold semantics helper (try_fold) to avoid divergent rules.
3. Integrate pass into optimization presets (-O1, -O2, -O3).
4. Add regression tests for both folded (2 + 2) and non-folded (value-dependent) cases.
5. Run targeted and full test suites.
6. Review PR, post review findings, and merge once checks are green.

Minimum validation

cargo +stable test -p llvm-transforms
cargo +stable test -q

Notes

• Preserve behavior on undefined/edge cases (e.g., division by zero stays unfolder).
• Keep pass ordering explicit in pipeline.rs to satisfy roadmap traceability.