Non-IEEE floating-point format based on IEEE754 single-precision floating-point number truncated to 16 bits.

Basic types.

IEEE754 half-precision floating-point format (16 bits wide).

proto3 requires the first enum value to be zero.

IR VERSION 3 published on Nov 3, 2017 - For operator versioning: - Added new message OperatorSetIdProto - Added opset_import in ModelProto - For vendor extensions, added domain in NodeProto.

The version field is always serialized and we will use it to store the version that the graph is generated from.

IR_VERSION 2 published on Oct 30, 2017 - Added type discriminator to AttributeProto to support proto3 users.

ErrCorruptedData ...

ErrNoDataFound ...

ErrNotYetImplemented ...

Attributes A named attribute containing either singular float, integer, string, graph, and tensor values, or repeated float, integer, string, graph, and tensor values.

ErrNotImplemented is returned for any operator or attribute.

Graphs A graph defines the computational logic of a model and is comprised of a parameterized list of nodes that form a directed acyclic graph based on their inputs and outputs.

Models ModelProto is a top-level file/container format for bundling a ML model and associating its computation graph with metadata.

Nodes Computation graphs are made up of a DAG of nodes, which represent what is commonly called a "layer" or "pipeline stage" in machine learning frameworks.

Operator Sets OperatorSets are uniquely identified by a (domain, opset_version) pair.

StringStringEntryProto follows the pattern for cross-proto-version maps.

Tensors A serialized tensor value.

For very large tensors, we may want to store them in chunks, in which case the following fields will specify the segment that is stored in the current TensorProto.

Defines a tensor shape.

Types The standard ONNX data types.

Defines information on value, including the name, the type, and the shape of the value.

Note: this enum is structurally identical to the OpSchema::AttrType enum defined in schema.h.

Versioning ONNX versioning is specified in docs/IR.md and elaborated on in docs/Versioning.md To be compatible with both proto2 and proto3, we will use a version number that is not defined by the default value but an explicit enum number.