[Transform] fix shape problems in add/mul->thres absorption

src/finn/transformation/streamline.py

@@ -248,7 +248,7 @@ def absorb_add_into_multi_threshold(model):
                 assert T is not None
                 start_name = n.input[0]
                 # compute new thresholds and set initializer
-                Tnew = T - A
+                Tnew = T - A.reshape(-1, T.shape[1])
                 model.set_initializer(threshold_name, Tnew)
                 # wire add input directly to MultiThreshold
                 consumer.input[0] = start_name
@@ -277,7 +277,9 @@ def absorb_mul_into_multi_threshold(model):
                 assert T is not None
                 start_name = n.input[0]
                 # compute new thresholds and set initializer
-                Tnew = T / A
+                Tnew = T / A.reshape(-1, T.shape[1])
+                # TODO: need to handle negative A values correctly; produce
+                # mul sign mask and merge into preceding matmul?
                 model.set_initializer(threshold_name, Tnew)
                 # wire add input directly to MultiThreshold
                 consumer.input[0] = start_name