Add path for to_edge_transform_and_lower that avoids EDGE_DO_NOT_DECOMP namespace

exir/program/_program.py

@@ -1082,6 +1082,27 @@ def keep(op):
     return list(filter(keep, ops_to_not_decompose))
 
 
+def _can_skip_using_EDGE_DO_NOT_DECOMP(
+    partitioner: Dict[str, List[Partitioner]], aten_programs: Dict[str, ExportedProgram]
+) -> bool:
+    # THe current design of using EDGE_DO_NOT_DECOMP to prevent decomposition
+    # has long standing issues.  _remove_invalid_ops_for_not_decompose was a band-aid to
+    # fix some of the issues, but more issues are coming up over time, including a new issue with SDPA
+    # and contiguous views: https://fb.workplace.com/groups/pytorch.edge.users/permalink/1796069037930048/
+    # EDGE_DO_NOT_DECOMP is only needed by partitioners that specify check_op_support
+    # As a temp fix, we give a more reliable path for backends that do not specify check_op_support
+    can_skip_using_EDGE_DO_NOT_DECOMP = True
+    for name, program in aten_programs.items():
+        if partitioner is not None:
+            for curr_partitioner in partitioner.get(name, []):
+                curr_ops_no_decomp, check_op_support = (
+                    curr_partitioner.ops_to_not_decompose(program)
+                )
+                if check_op_support is not None:
+                    can_skip_using_EDGE_DO_NOT_DECOMP = False
+    return can_skip_using_EDGE_DO_NOT_DECOMP
+
+
 def _gen_edge_manager_for_partitioners(
     partitioner: Dict[str, List[Partitioner]],
     aten_programs: Dict[str, ExportedProgram],
@@ -1101,37 +1122,54 @@ def _gen_edge_manager_for_partitioners(
           on nodes with preserved aten targets. They are then replaces with transformed ops to
           keep them through the second pass of decompositions
     """
+
+    can_skip_using_EDGE_DO_NOT_DECOMP = _can_skip_using_EDGE_DO_NOT_DECOMP(
+        partitioner, aten_programs
+    )
+
     ops_set_to_not_decompose_by_program = {}
     edge_programs: Dict[str, ExportedProgram] = {}
     for name, program in aten_programs.items():
         if partitioner is not None:
             # preserve all ops listed by all partitioners first
             all_ops_no_decomp = set()
+
+            # This holds the subset of all_ops_no_decomp that actually need preservation, i.e.,
+            # the ones where the decomposition table has an entry for the op
+            all_ops_no_decomp_needing_preservation = []
             for curr_partitioner in partitioner.get(name, []):
                 curr_ops_no_decomp, _ = curr_partitioner.ops_to_not_decompose(program)
-                curr_ops_no_decomp = _remove_invalid_ops_for_not_decompose(
-                    curr_ops_no_decomp
-                )
+                if not can_skip_using_EDGE_DO_NOT_DECOMP:
+                    curr_ops_no_decomp = _remove_invalid_ops_for_not_decompose(
+                        curr_ops_no_decomp
+                    )
                 all_ops_no_decomp |= set(curr_ops_no_decomp)
 
             table = _default_decomposition_table()
 
             for op in all_ops_no_decomp:
-                table.pop(op, None)
+                if table.pop(op, None) is not None:
+                    all_ops_no_decomp_needing_preservation.append(op)
 
             program = program.run_decompositions(table)
             # Among all the preserved aten ops, use the check_op_fn to do an additional
             # check on which ops need to be preserved and which ops need to be decomposed
             # Those which are truly preserved will be replaced with transformed ops
-            ops_set_to_not_decompose_by_program[name] = (
-                _replace_aten_ops_with_transformed_ops(name, program, partitioner) or []
-            )
-        program = program.run_decompositions(_default_decomposition_table())
+            if can_skip_using_EDGE_DO_NOT_DECOMP:
+                ops_set_to_not_decompose_by_program[name] = (
+                    all_ops_no_decomp_needing_preservation
+                )
+            else:
+                ops_set_to_not_decompose_by_program[name] = (
+                    _replace_aten_ops_with_transformed_ops(name, program, partitioner)
+                    or []
+                )
 
-        _restore_transformed_ops_to_aten_ops(program)
+        if not can_skip_using_EDGE_DO_NOT_DECOMP:
+            program = program.run_decompositions(_default_decomposition_table())
+            _restore_transformed_ops_to_aten_ops(program)
 
         edge_programs[name] = program
-
         edge_programs[name] = _generate_edge_program(
             name,
             config,