MLBEDSW-6180: Protect overwrite of subgraph output
Make sure output from subgraph is write protected and
not overwritten by an element wise op.
Signed-off-by: Johan Alfven <johan.alfven@arm.com>
Change-Id: Ie26979913843c62794c5346a315b7089206850e0
diff --git a/ethosu/vela/extract_npu_subgraphs.py b/ethosu/vela/extract_npu_subgraphs.py
index 015634c..ada76f2 100644
--- a/ethosu/vela/extract_npu_subgraphs.py
+++ b/ethosu/vela/extract_npu_subgraphs.py
@@ -120,6 +120,14 @@
call_ps.primary_op.outputs.append(new_tens)
new_tens.ops = [call_ps.primary_op]
+ # Elementwise op can not overwrite ifm if input is used by many consumers
+ if orig_tens in npu_subgraph.input_tensors and len(orig_tens.consumers()) > 1:
+ new_tens.ifm_write_protected = True
+
+ # Elementwise op can not overwrite ifm if tensor is used as output from sub graph
+ if orig_tens in npu_subgraph.output_tensors:
+ new_tens.ifm_write_protected = True
+
for op in list(orig_tens.consumers()):
if op is None:
continue # Subgraph consumers handled separately.