MLBEDSW-7343: MLCE: Unsupported STRIDED_SLICE with negative index and shrinking an axis
- The problem was that the end values of STRIDED_SLICE operators
were not taking the shrink_axis_mask into account
- The fix is simply to ignore the end value set on the operator
and calculate one based upon shrinking the axis
Change-Id: I2e5f2d3c9b08035dfd9b1629c775408f2356d1cf
Signed-off-by: Tim Hall <tim.hall@arm.com>
diff --git a/ethosu/vela/operation.py b/ethosu/vela/operation.py
index de35dcc..f85cb4b 100644
--- a/ethosu/vela/operation.py
+++ b/ethosu/vela/operation.py
@@ -1,4 +1,4 @@
-# SPDX-FileCopyrightText: Copyright 2020-2022 Arm Limited and/or its affiliates <open-source-office@arm.com>
+# SPDX-FileCopyrightText: Copyright 2020-2023 Arm Limited and/or its affiliates <open-source-office@arm.com>
#
# SPDX-License-Identifier: Apache-2.0
#
@@ -458,19 +458,6 @@
return act
-def get_slice_offsets(input_shape: List[int], offset_tens: Tensor, offset_mask: int, is_begin: bool = True):
- # For strided slice operator: get start or end offsets
- offsets = len(input_shape) * [0] if is_begin else input_shape[:]
- for idx in range(len(input_shape)):
- # If the i:th bit in the mask is set then the value on offset_tens[i] should be ignored
- if (offset_mask & (1 << idx)) == 0:
- offsets[idx] = offset_tens.values[idx]
- if offsets[idx] < 0:
- # Convert offset to positive value
- offsets[idx] += input_shape[idx]
- return offsets
-
-
class Operation:
"""Class representing a Neural Network operation. Has a name, a type,
input and output tensors, as well as an attribute dictionary."""
@@ -775,17 +762,18 @@
outputs = self.outputs
# Extract masks
- begin_mask = self.attrs["begin_mask"]
ellipsis_mask = self.attrs["ellipsis_mask"]
- end_mask = self.attrs["end_mask"]
new_axis_mask = self.attrs["new_axis_mask"]
shrink_axis_mask = self.attrs["shrink_axis_mask"]
# shrink_axis_mask/new_axis_mask/ellipsis_mask is not supported by the Operation class but the operation
# may have the attribute modified and handled in the graph optimization phase.
assert shrink_axis_mask == new_axis_mask == ellipsis_mask == 0
- offset_start = get_slice_offsets(input_tens.shape, begin_tens, begin_mask, is_begin=True)
- offset_end = get_slice_offsets(input_tens.shape, end_tens, end_mask, is_begin=False)
+ # use the begin and end values that were calculated in the model semantic check. this is because the end
+ # values can be affected (ignored) by the shrink_axis_mask and this mask may have been changed in the graph
+ # optimizer (see assert above)
+ offset_start = self.attrs["offset_begin"]
+ offset_end = self.attrs["offset_end"]
elif self.type == Op.UnpackReshaped:
# Requires fixup_unpack_output to be called before this point
input_tens = self.inputs[0]