shape_generator.h#

Shape-inference functions for ONNX operators in the generator family.

namespace ONNX_LIGHT_NAMESPACE
namespace onnx_optim
namespace shapes
namespace generator#

Functions

void ComputeShapeConstant(ShapesContext &ctx, const NodeProto &node)#

Computes the output :cpp:class:OptimTensor of a Constant node and stores it in ctx.

Constant declares its output as the value of exactly one of the attributes value, sparse_value, value_int, value_ints, value_float, value_floats, value_string or value_strings (which one is allowed depends on the schema revision, but for shape inference the union of every revision is accepted). The output dtype and shape are taken from the present attribute.

When the resulting tensor carries at most :cpp:var:kConstantValueAsShapeMaxElements integer elements and has rank at most one — i.e. it is small enough to plausibly be used later as a shape input of operators such as Reshape, Expand or ConstantOfShape — its integer values are also recorded via :cpp:func:OptimTensor::SetValueAsShape. This mirrors the upstream ONNX shape-inference data-propagation behaviour for small integer constants.

Parameters:

  • ctx – In/out context. On return contains an entry for node.output(0) describing the constant output.

  • node – The Constant NodeProto whose output should be described. node.op_type() must be "Constant" and node must declare at least one output.

Throws:

std::invalid_argument – if node.op_type() is not "Constant", if node has no output, or if the attributes do not specify exactly one of the allowed value forms.

Variables

constexpr int64_t kConstantValueAsShapeMaxElements = 8#

Maximum element count of a Constant value tensor for which :cpp:func:ComputeShapeConstant populates the output :cpp:func:OptimTensor::ValueAsShape annotation. Constants beyond this threshold are not data-propagated (the output dtype and shape are still inferred normally).