Crate onnx_runtime_optimizer 

onnx-runtime-optimizer

Device-independent graph→graph optimization passes for the ORT 2.0 runtime (see docs/architecture/ORT2.md §18 “Optimization Passes”). This is the first Phase-2 crate: pure, safe Rust graph rewriting over onnx_runtime_ir — no CUDA, no ORT C library, no FFI.

What lives here

Concept	Type
Pass contract	OptimizationPass, PassContext, run_passes
Dead-code removal	DeadNodeElimination
Bounded constant folding	ConstantFolding
Reusable provider-scoped fusion machinery	OpFusion, FusionPattern, PatternMatch
Errors	OptimizerError, Result

Pipeline

default_passes returns only the device-independent passes implemented here, in pipeline order: ConstantFolding → DeadNodeElimination. OpFusion remains in this crate as reusable machinery, but providers must schedule it themselves so private fused ops are introduced only when the selected provider can run them.

Deferred (Phase 2b / Phase 3)

The full pipeline in docs/architecture/ORT2.md §18.1 also lists passes that depend on crates or analyses not yet built. They are intentionally not implemented here and are listed in default_passes’s source in their eventual pipeline position: ShapeInference (the loader owns inference for now), AttentionFusionPass, LayoutPropagation, PlacementOptimizer, TransferInsertion, InPlaceDetection, MemoryPlanning, CudaGraphRegionDetection, and OverlapScheduling.

Structs

ConstantFolding

Folds constant-input nodes into initializers (bounded, integer/shape only).

DeadNodeElimination

Removes nodes that do not contribute to any graph output.

FusionPattern

A fusion rule: an op-type sequence rewritten to a single replacement op.

OpFusion

The op-fusion pass: applies each FusionPattern to fixpoint.

PassContext

Shared, read-only context threaded through every pass.

PatternMatch

A matched occurrence of a FusionPattern in a graph.#[derive(Clone, Debug)]

Enums

OptimizerError

Crate-level error for the optimization pipeline.

Constants

CONTRIB_DOMAIN

The private contrib domain under which the optimizer emits every fused op.

Traits

InitializerResolver

Resolves graph initializer descriptors to their backing bytes.

OptimizationPass

A single graph→graph rewrite (see docs/architecture/ORT2.md §18.1).

Functions

default_fusion_patterns

The default device-independent fusion patterns.

default_passes

The device-independent Phase-1 pass pipeline, in run order.

run_passes

Run passes over graph in order.

Type Aliases

Result

A convenience Result alias for optimizer operations.