MLBEDSW-8575 Tests fails on conv networks

Fixed a problem where the compiler incorrectly called the
mlw_codec to create an empty weight stream for the second
weight core.
Also added code to the mlw_codec to detect this as an value
error rather than a memory error.

Change-Id: I463846cecb1178f8fbf04dc3e39bd6965cb8ddfc
Signed-off-by: Fredrik Svedberg <fredrik.svedberg@arm.com>

2 files changed, 33 insertions, 2 deletions

diff --git a/ethosu/mlw_codec/mlw_codecmodule.c b/ethosu/mlw_codec/mlw_codecmodule.c
index 1f172ee..5d37302 100644
--- a/ethosu/mlw_codec/mlw_codecmodule.c
+++ b/ethosu/mlw_codec/mlw_codecmodule.c
@@ -91,6 +91,7 @@ method_reorder_encode (PyObject *self, PyObject *args)
     if ((int)PyArray_NDIM(input_ndarray_object) < 4)
     {
         PyErr_SetString(PyExc_ValueError, "Invalid input shape");
+        Py_DECREF(input_ndarray_object);
         return NULL;
     }
 
@@ -99,6 +100,34 @@ method_reorder_encode (PyObject *self, PyObject *args)
     int kernel_width = (int)PyArray_DIM(input_ndarray_object, 2);
     int ifm_depth = (int)PyArray_DIM(input_ndarray_object, 3);
 
+    if (ofm_depth < 1)
+    {
+        PyErr_SetString(PyExc_ValueError, "Invalid output depth");
+        Py_DECREF(input_ndarray_object);
+        return NULL;
+    }
+
+    if (ifm_depth < 1)
+    {
+        PyErr_SetString(PyExc_ValueError, "Invalid input depth");
+        Py_DECREF(input_ndarray_object);
+        return NULL;
+    }
+
+    if (kernel_height < 1)
+    {
+        PyErr_SetString(PyExc_ValueError, "Invalid kernel height");
+        Py_DECREF(input_ndarray_object);
+        return NULL;
+    }
+
+    if (kernel_width < 1)
+    {
+        PyErr_SetString(PyExc_ValueError, "Invalid kernel width");
+        Py_DECREF(input_ndarray_object);
+        return NULL;
+    }
+
     int16_t* brick_weights = (int16_t*)PyArray_DATA(input_ndarray_object);
     int brick_strides[4];
     for (int i = 0; i < 4; i++)
@@ -107,6 +136,7 @@ method_reorder_encode (PyObject *self, PyObject *args)
         if (stride % sizeof(int16_t))
         {
             PyErr_SetString(PyExc_ValueError, "Invalid stride");
+            Py_DECREF(input_ndarray_object);
             return NULL;
         }
         brick_strides[i] = stride / sizeof(int16_t);
@@ -114,6 +144,7 @@ method_reorder_encode (PyObject *self, PyObject *args)
     if ((unsigned)PyArray_ITEMSIZE(input_ndarray_object) != sizeof(int16_t))
     {
         PyErr_SetString(PyExc_ValueError, "Invalid input type");
+        Py_DECREF(input_ndarray_object);
         return NULL;
     }
     uint8_t* output_buffer = NULL;
diff --git a/ethosu/vela/weight_compressor.py b/ethosu/vela/weight_compressor.py
index 50ae26c..a580fb6 100644
--- a/ethosu/vela/weight_compressor.py
+++ b/ethosu/vela/weight_compressor.py
@@ -1,4 +1,4 @@
-# SPDX-FileCopyrightText: Copyright 2020-2023 Arm Limited and/or its affiliates <open-source-office@arm.com>
+# SPDX-FileCopyrightText: Copyright 2020-2024 Arm Limited and/or its affiliates <open-source-office@arm.com>
 #
 # SPDX-License-Identifier: Apache-2.0
 #
@@ -420,7 +420,7 @@ def encode_weight_and_scale_tensor(
 
         # For each core, deinterleave weights/scales from the larger volume
         # and generate separate compressed streams.
-        for core in range(0, min(arch.ncores, full_ofm_depth)):
+        for core in range(0, min(arch.ncores, depth_length)):
 
             core_block_depth = int((ofm_block_depth + arch.ncores - 1 - core) // arch.ncores)