Reshape bug fix (#1684)

* Revert 1c639c8393

1c639c8393?diff=unified&w=0

* Refactor by @laggui

* Refactor unsqueeze

crates/burn-import/src/onnx/dim_inference.rs

@@ -195,13 +195,18 @@ fn concat_update_outputs(node: &mut Node) {
 
     node.outputs[0].ty = ArgType::Tensor(tensor.clone());
 }
+
 fn reshape_update_outputs(node: &mut Node) {
-    let shape = match node.inputs.get(1) {
-        Some(input) => match &input.value {
-            Some(Data::Int64s(shape)) => Some(shape.clone()),
-            _ => panic!("Reshape: invalid input types"),
-        },
-        None => node.attrs.get("shape").cloned().map(|v| v.into_i64s()),
+    let shape = if node.inputs.len() == 2 {
+        match &node.inputs[1].value {
+            Some(value) => match value {
+                Data::Int64s(shape) => Some(shape.clone()),
+                _ => panic!("Reshape: invalid input types"),
+            },
+            None => None,
+        }
+    } else {
+        node.attrs.get("shape").cloned().map(|v| v.into_i64s())
     };
 
     let output = match &node.outputs[0].ty {
@@ -252,24 +257,34 @@ fn reduce_mean_update_outputs(node: &mut Node) {
 
 /// Update the output tensor dimension based on the "axes" attribute or the second input
 fn unsqueeze_update_output(node: &mut Node) {
-    let axes = match node.inputs.get(1) {
-        Some(input) => match &input.value {
-            Some(Data::Int64s(axes)) => Some(axes.clone()),
-            _ => panic!("Unsqueeze: invalid input types"),
-        },
-        None => node.attrs.get("axes").cloned().map(|v| v.into_i64s()),
+    let axes = if node.inputs.len() == 2 {
+        match &node.inputs[1].value {
+            Some(value) => match value {
+                Data::Int64s(axes) => Some(axes.clone()),
+                _ => panic!("Unsqueeze: invalid input types"),
+            },
+            None => None,
+        }
+    } else {
+        node.attrs.get("axes").cloned().map(|v| v.into_i64s())
     };
 
+    // need output way up here to avoid borrowing issues
     let input = match &node.inputs[0].ty {
         ArgType::Tensor(tensor) => tensor.clone(),
-        ty => panic!("Unsqueeze: invalid output type ({ty:?})"),
+        _ => panic!("Unsqueeze: invalid output types"),
+    };
+
+    let output = match &node.outputs[0].ty {
+        ArgType::Tensor(tensor) => tensor.clone(),
+        _ => panic!("Unsqueeze: invalid output types"),
     };
 
     if let Some(axes) = axes {
         node.outputs[0].ty = ArgType::Tensor(TensorType {
             dim: input.dim + axes.len(),
             shape: None, // shape is calculated at runtime
-            ..input
+            ..output
         });
     }
 }