Module jit 

Phase 3: Cranelift JIT compilation of Polydat Kernels.

Generates native machine code from the DAG. The entire kernel becomes a single function: fn(coords: *const u64, buffer: *mut u64). No closures, no function pointers, no gather/scatter — direct buffer reads and writes with inlined arithmetic.

The buffer is Vec<u64>. For f64 values, they are stored as their bit representation (f64::to_bits() / f64::from_bits()). The JIT uses Cranelift bitcast (free, no instruction emitted) to convert between i64 and f64 representations when crossing type boundaries.

Feature-gated behind jit.

For nodes that can’t be JIT-compiled inline (hash, shuffle, interleave), we emit a call to an extern function. Simple ops are fully inlined, complex ops are extern calls with zero overhead beyond the call itself.

Modules

host_isa

One source of truth for the effective native Cranelift ISA.

simd

Cranelift-SIMD compute kernels for element-wise vector math (type_system_alignment.md §8.2, execution level).

Structs

JitCode

Finalized native code, shared by every kernel created from one program. The module’s memory is never written after finalization, so sharing it across threads is sound; the wrapper exists so a kernel clone is a new state over the same code. The slot kits the code calls by address live beside it, for as long as it does.

SlotKitRef

A node’s slot kit as native code holds it: shared by every kernel compiled from the program, compared by identity.

Enums

JitOp

Description of a JIT step — what operation to generate.

RegLaneRead

The register lane reads with a named lowering: each returns the lane as the slot word its port stores.

RegProducer

The register producers that run through a helper: a bounds check on a wire index, or a lane operation Cranelift has no instruction for. Each writes its word into the output slots.

VecProducer

The vector producers with a named lowering (compiled_handles.md §6): each writes its result into the step’s own F32 entry and publishes the pair.

VecReducer

The vector reductions with a named lowering: each returns the bits of its f64 result.

Functions

classify_node

Classify a Polydat node into a JIT-able operation.

classify_node_typed

Classify a node with the types of its wire inputs known. A node with a named native lowering takes it; any other node with a kit is a JitOp::SlotCall of that kit, so a reference pair on either side is no bar to native code, and neither is nondeterminism or a side effect: the kernels that run the code keep such a step’s currency its own (a segment of its own on the hybrid kernel, a never-current step on pure native code). A node with neither stays interpreted.

Type Aliases

JitParts

A raw native kernel taken apart: its entry point and its code.

NativeFn

A native entry point over a state’s slot buffer and scratch.

NativeProvFn

The provenance variant: a clean flag per step follows the scratch.