volar-ir

Volar IR and VAFFLE: a reusable compiler IR, lowering pipeline, and optimization passes for WASM-derived circuits.

This repo holds the IR/circuit-compilation layer that was split out of volar, Portal's ZK-proof / garbled-circuit / MPC toolkit. volar still owns everything downstream of a boolean circuit — ZK proof weaving, garbled-circuit weaving — and the spec-integration side of compiling volar-spec through to C/LLVM/WASM, and consumes the crates here as a regular dependency.

What's here

• VAFFLE (vaffle, volar-vaffle-target) — a Volar-aware WASM-IR dialect, and its lowering from WAFFLE/VAFFLE into Volar IR.
• Volar IR / Boolar IR (volar-ir, volar-ir-common, volar-ir-config, volar-ir-text) — the field-level and boolean-circuit-level SSA IRs.
• Lowerings (volar-ir-passes): movfuscation (collapsing branching CFGs into a single oblivious dispatch block) and circuit lowering.
• Virtualization (volar-ir-virt): dispatch-mode block interpretation.
• Optimizations (volar-ir-opt): DCE, CSE, constant folding, and store-forwarding, across Volar IR, Boolar IR, and VAFFLE.
• LIR (volar-lir, volar-lir-text, volar-lir-saved, volar-lir-test-corpus) — the mid-level IR that this pipeline and the backends below build on.
• Backends (crates/backends/volar-c-backend, volar-llvm-backend, volar-wasm-backend) — the LirTarget implementations that lower LIR to C99, LLVM IR, and WASM, plus their pure-LIR-level tests. The spec-integration tests (compiling real volar-spec source through volar-compiler + volar-lir-codegen into these backends) stay in volar as volar-c-backend-spec-tests, since they exercise crates that are out of scope here.
• Fuzz/property tests (crates/fuzz/volar-fuzz, fuzz/) for the passes above.

See docs/pipeline.md for how these fit together, and docs/ generally for per-crate design docs carried over from volar.

Building

cargo check --workspace
cargo test --workspace

Building inside a portal-hot-style checkout (as a sibling of volar/, waffle-/, wax/) picks up the root .cargo/config.toml patches for portal-pc-waffle-ir/portal-pc-waffle-frontend/wax-meta. Building this repo fully standalone requires those as real git dependencies (already the default in Cargo.toml).

Relationship to volar

volar depends on the crates here via a [patch] entry when built inside the same checkout, or a normal git dependency otherwise. Two things stay in volar deliberately, not here:

• volar-discipline — the ZK/non-ZK proving-discipline typestate, which is specific to volar's cryptographic pipeline, not to IR mechanics.
• volar-ir-lir-target — the Volar-IR→LIR-for-backends lowering, since it depends on volar-compiler/volar-lir-codegen, which are backend/codegen infrastructure out of scope here.
• volar-lir-codegen itself — the IrModule/IrCfgModule → LirTarget lowering, since it depends on volar-compiler.
• volar-c-backend-spec-tests — the spec-integration and volar-lir-codegen-dependent tests for the C backend (parses real volar-spec source, exercises volar-weaver).
• fuzz/fuzz_targets/fuzz_vole_circuit_completeness.rs — it also exercises volar-spec, so it's an integration test of the crypto pipeline's consumption of this IR, not a test of the IR itself.