fix optim issue

Cargo.toml

@@ -80,6 +80,7 @@ dyn-clone = "1.0.4"
 env_logger = "0.10"
 flatbuffers = "23.1.21"
 flate2 = "1.0.20"
+fs-err = "2"
 fs2 = "0.4.3"
 getrandom = "0.2"
 half = { version="2.2.1", features = [ "std", "num-traits" ] }

core/src/optim/push_split_down.rs

@@ -1,7 +1,7 @@
 use crate::internal::*;
 
-use tract_itertools::Itertools;
 use crate::optim::OptimizerSession;
+use tract_itertools::Itertools;
 
 #[derive(Clone, Debug)]
 pub struct PushSplitDown;
@@ -10,16 +10,26 @@ impl super::TypedPass for PushSplitDown {
     fn reset(&mut self) -> TractResult<()> {
         Ok(())
     }
-    fn next(&mut self, _session: &mut OptimizerSession, model: &TypedModel) -> TractResult<Option<TypedModelPatch>> {
+    fn next(
+        &mut self,
+        _session: &mut OptimizerSession,
+        model: &TypedModel,
+    ) -> TractResult<Option<TypedModelPatch>> {
         let mut patch = TypedModelPatch::default();
         for node in model.eval_order()? {
             for output in &model.node(node).outputs {
                 for (a, b) in output.successors.iter().tuple_combinations() {
+                    if a.node == b.node {
+                        // found where a square is implemented using a mul with duplicate input
+                        continue;
+                    }
                     if patch.obliterate.contains(&b.node) {
                         continue;
                     }
                     // dont merge outputs.
-                    if model.outputs.contains(&a.node.into()) && model.outputs.contains(&b.node.into()) {
+                    if model.outputs.contains(&a.node.into())
+                        && model.outputs.contains(&b.node.into())
+                    {
                         continue;
                     }
                     let a = model.node(a.node);