MLBEDSW-6384: Updated weight buffering cycle calculation
- The npu cycles are not correct calculated when only
one weight buffer is used, since weights can not
be fetched in parallel.
- Added new calculation in the single buffer case.
Signed-off-by: Johan Alfven <johan.alfven@arm.com>
Change-Id: I8568912d11d137a298225ab77b8b3272613c76f6
diff --git a/ethosu/vela/npu_performance.py b/ethosu/vela/npu_performance.py
index b7607e6..0e2e3ca 100644
--- a/ethosu/vela/npu_performance.py
+++ b/ethosu/vela/npu_performance.py
@@ -50,6 +50,7 @@
from .tensor import BandwidthDirection
from .tensor import MemArea
from .tensor import TensorPurpose
+from .tensor import TensorSubPurpose
from .tflite_mapping import optype_to_builtintype as tflite_optype_to_builtintype
from .tosa_mapping import optype_to_tosa_op_type as tosa_optype_to_tosa_op_type
from .weight_compressor import WeightKey
@@ -674,10 +675,18 @@
)
# Add cycles for Weight + Scale Transfer
- cycles_a[PassCycles.Npu] = max(
- cost.full_weight_transfer_cycles - slack_cycles + cost.slack_buffering_cycles,
- cycles.op_cycles + max(ws_first_transfer_cycles - slack_cycles, 0),
- )
+ if cost.buffered_weight_tensors[0].sub_purpose == TensorSubPurpose.DoubleBuffer:
+ # Double buffer - weights can be fetched in parallel
+ cycles_a[PassCycles.Npu] = max(
+ cost.full_weight_transfer_cycles - slack_cycles + cost.slack_buffering_cycles,
+ cycles.op_cycles + max(ws_first_transfer_cycles - slack_cycles, 0),
+ )
+ else:
+ # Standard buffer - weights can not be fetched in parallel so weight transfer
+ # must be included in the result
+ cycles_a[PassCycles.Npu] = (
+ cycles.op_cycles + cost.full_weight_transfer_cycles - min(ws_first_transfer_cycles, slack_cycles)
+ )
# Add cycles for LUT Transfer
cycles_a[PassCycles.Npu] += lut_transfer_cycles