ExportedProgram.transform now updates graph_signature automatically (#107080)
Update graph_signature according to graph after transformation.
Transformations can lead to node name changes, which are used in
graph_signature to identify inputs and outputs. Therefore, after each
transformation, we need to update the graph_signature according to
new node names.
WARNING: This implementation makes a few assumptions
- The transformation doesn't change number of inputs/outputs
- Each input/output still has the same meaning.
- For inputs, that means that the inputs in transformed
graph map to the same lifted parameter/buffer or user
input as the input of the same position in the graph
before transformation.
- Similarly for outputs, each output should correspond to the
same mutated buffer or user output as the output value of
the same position in the graph before transformation.
It is difficult to programatically validate these assumptions, but they
should hold true most of the time as inputs/outputs of the graph rarely
need to be changed.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/107080
Approved by: https://github.com/tugsbayasgalan
