[mpact][compiler] add torch aten decomposition features (#53)

python/CMakeLists.txt

diff --git a/python/CMakeLists.txt b/python/CMakeLists.txt
index aab4f9a..4d72267 100644
--- a/python/CMakeLists.txt
+++ b/python/CMakeLists.txt
@@ -52,9 +52,10 @@
   MLIRPythonExtension.Core
   MLIRPythonExtension.RegisterEverything
 
-  # We need the FxImporter from torch-mlir
+  # We need various modules form torch-mlir.
   TorchMLIRPythonSources.Importers
   TorchMLIRPythonSources.Dialects
+  TorchMLIRPythonSources.PublicAPI
   TorchMLIRPythonExtensions
 
   MPACTPythonSources

python/mpact/mpactbackend.py

diff --git a/python/mpact/mpactbackend.py b/python/mpact/mpactbackend.py
index 3e8ae4b..a98bc60 100644
--- a/python/mpact/mpactbackend.py
+++ b/python/mpact/mpactbackend.py
@@ -15,6 +15,7 @@
 from mpact.ir import Module
 from mpact.dialects import torch as torch_d
 from mpact.execution_engine import *
+from mpact.extras.fx_decomp_util import get_decomposition_table
 from mpact.extras.fx_importer import FxImporter, SparsityMeta
 from mpact.ir import *
 from mpact.passmanager import *
@@ -61,14 +62,6 @@
                 pm.enable_ir_printing()
             pm.run(module.operation)
     except Exception as e:
-        # TODO: More robust.
-        # - don't arbitrarily clutter up /tmp. When a test suite has many
-        #   tests, this can be a big disk cost (also, /tmp/ is frequently a
-        #   RAM fs, which increases worries about capacity).
-        # - don't have colliding filenames (hard to do without cluttering
-        #   up /tmp)
-        # - if we do have have colliding filenames, writes should at least
-        #   avoid being racy.
         filename = os.path.join(tempfile.gettempdir(), module_name + ".mlir")
         with open(filename, "w") as f:
             f.write(asm_for_error_report)
@@ -398,6 +391,9 @@
     # Build the regular FX traced graph with only dense arguments
     # (the current version would crash otherwise, see issue above).
     prog = torch.export.export(f, dargs, kwargs)
+    decomposition_table = get_decomposition_table()
+    if decomposition_table:
+        prog = prog.run_decompositions(decomposition_table)
     # Annotate sparse arguments in the graph and apply some very
     # basic propagation rules for sparsity.
     specs = prog.graph_signature.input_specs
@@ -412,7 +408,6 @@
                     node.meta["sparsity"] = sparse_metadata(args[k])
                 k = k + 1
         elif node.op == "call_function":
-            # TODO: use upstream _opname implementation when available
             opname = node.target._schema.name.split("::")[1]
             # Zero preserving elt-wise unary op.
             if opname in {"abs", "neg", "relu", "sin"}: