[pytorch][nnc] external function call to xnnpack ops (#59525)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/59525
This PR added NNC external function call binding for two XNNPack ops:
- prepacked::linear_clamp_run
- prepacked::conv2d_clamp_run
Both ops take two arguments: a regular input tensor and a prepacked context
object that contains other parameters like weights/bias/etc. The prepacked
context object's type is a custom class.
NNC doesn't generate assembly code that reads the content of the prepacked
object directly. It simply passes it into the XNNPack ops wrapper, so both
NNC and the generated assembly code don't need to know the custom class type.
At compilation time, we use a size-1 dummy tensor as the placeholder for the
prepacked XNNPack context object.
At runtime, we pass in the raw pointer of the XNNPack context object as if it
were a regular tensor storage data pointer.
Inside the external function call wrapper, we reinterpret_cast the raw pointer
back to the custom class type before dispatching to the XNNPack ops.
ghstack-source-id: 132135512
Test Plan: unit test
Reviewed By: bertmaher
Differential Revision: D28924934
fbshipit-source-id: 15326b35dc6c022f4c3f247a2037c361e06e80b4
