April 2026 (2026-04): Focused on expanding synthesis coverage, hardening structural tooling, and stabilizing constant storage to support scalable hardware design flows in CIRCT. Deliveries improve op coverage, hashing reliability, and cross-region constant handling, enabling broader design support and more robust downstream tooling.

Month: 2026-03 — CIRCT optimization and canonicalization work across llvm/circt and OpenXiangShan/circt. Delivered targeted synthesis-area reductions and a robust canonicalization pass, with an emphasis on business value through smaller silicon area, more predictable synthesis outcomes, and faster feedback cycles. Key deliverables include: - llvm/circt: LowerVariadic Pass Optimization for Area Reduction, implementing a subset-sharing heuristic to reuse existing AIG operations and reduce redundant gates; initial commit 5b4c0fe1a1cf6fa91c61e214894121f28e205a54, followed by a reland fix 63e48f8a9f5b4e53f42a69410e02c542b3cb3964 to stabilize correctness after changes. - OpenXiangShan/circt: Synthesized Choice Canonicalization, introducing a worklist-based transitive merge for synth.choice to flatten nested/shared choices and deduplicate operands (commit 99de008488151010b0fa06f9d8469e04d5f4028c). Overall, these changes improve synthesis efficiency, reduce gate count and area, and enhance maintainability of critical optimization and canonicalization passes.