shape_reduction.h#

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

namespace ONNX_LIGHT_NAMESPACE
namespace onnx_optim
namespace shapes
namespace reduction#

Functions

void ComputeShapeReduceSum(ShapesContext &ctx, const NodeProto &node, const char *data, const char *axes)#

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

ReduceSum reduces the input tensor along a set of axes. The output dtype always matches the input dtype (type constraint T); the output shape is the input shape with the reduced axes either dropped (keepdims=0) or replaced by 1 (keepdims=1, the default).

The way axes are specified depends on the opset:

  • opset < 13: axes is a repeated INTS attribute. If absent every dimension is reduced.

  • opset >= 13: axes is an optional second input. When the input is missing or empty the behaviour is controlled by the noop_with_empty_axes attribute (default 0): 0 means reduce all axes, 1 means identity (no axes reduced).

    When the axes input is provided this function looks at the :cpp:func:OptimTensor::ValueAsShape annotation of axes to identify the reduced axes. If the annotation is missing the output rank can still be inferred when keepdims=1 (same rank as the input, with each previously-known dimension kept as is and reduced positions left symbolic) or when the number of axes is known via the shape of axes (keepdims=0: output rank = input rank − number of axes, with every dimension marked symbolic).

Parameters:

  • ctx – In/out context. Must already contain an entry for data and, when provided and non-empty, axes. On return it also contains an entry for node.output(0).

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

  • data – Name of the data input value to read from ctx. Must be present in ctx.

  • axes – Name of the axes input value to read from ctx for opset >= 13, or nullptr / empty string when the axes input is omitted (use the attribute / default “reduce all” behaviour). For opset < 13 the value is ignored and the axes attribute is consulted.

Throws:

  • std::invalid_argument – if node.op_type() is not "ReduceSum", if node has no output, or if an axis value is out of range.

  • std::out_of_range – if data (or axes when given) is not present in ctx.