[TIR] Fix PlanAndUpdateBufferAllocationLocation not visiting constant buffer

[masahi]

#13560 is supposed to change only the order in which buffers are visited, but the created buffer_alloc_recorder_ misses buffers associated with AllocateConst nodes. These buffers are not part of func->buffer_map, and appear only in read or match_buffer regions, so they are not caught by existing visitors for BufferLoadNode and BufferStoreNode.

Since constant buffers are not correctly handled by PlanAndUpdateBufferAllocationLocation now, tuning on Hexagon is currently broken with this error. This PR fixes this.

E             File "/home/fparizi/src/tvm_src/src/tir/transforms/plan_update_buffer_allocation_location.cc", line 163
E           TVMError: 
E           ---------------------------------------------------------------
E           An error occurred during the execution of TVM.
E           For more information, please see: https://tvm.apache.org/docs/errors.html
E           ---------------------------------------------------------------
E             Check failed: (buffer_data_to_buffer_.count(source_var)) is false:

Since creating a TVMScript-based test case involving constant buffers (AllocateConst) is difficult, I hope we can merge this simple PR without a test case.

cc @Hzfengsy @FredJia-intellif

[tvm-bot]

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• cc @Hzfengsy, @junrushao _{See #10317 for details}

_{Generated by tvm-bot}

[Hzfengsy]

I'm sorry I missed this when reviewing #13560.

BTW, Could you please add regression tests for Hexagon? Then we can make sure the const tensors can be considered in every PR.

[masahi]

BTW, Could you please add regression tests for Hexagon?

Since we cannot parse a large constant via TVMScript, creating a TVMScript-based test case involving constant buffers (AllocateConst) is difficult or near impossible. But if there is a way to create TensorIR program directly from Relay (using link-params=True to generate AllocateConst), then I can probably create a minimum test case for PlanAndUpdateBufferAllocationLocation.

I think there is no way to create TensorIR from Relay (via CreatePrimFunc) directly in Python currently (everything is contained in TECompiler). But yes, Hexagon tuning keeps breaking due to AllocateConst not handled properly in PRs, so I'll try to fix this situation.

[masahi]

Regression test is added in #13606