More fixes to outline

• Add region node in between start and return when none exists, just for outlining
• Move collapse returns and inserting extra region to outline pass in pass.rs, since analysis info needs to get rebuilt (god this is ugly PM refactor very necessary)
• Fix not using convert_id when building returns in outlining

hercules_opt/src/outline.rs

@@ -228,27 +228,27 @@ pub fn outline(
             outlined.nodes.push(Node::Parameter { index });
         }
 
+        let convert_id = |old| {
+            if let Some(new) = old_to_new_id.get(&old) {
+                // Map a use inside the partition to its new ID in the
+                // outlined function.
+                *new
+            } else if let Some(idx) = outside_id_to_param_idx.get(&old) {
+                // Map a data use outside the partition to the ID of the
+                // corresponding parameter node.
+                NodeID::new(idx + 1)
+            } else {
+                // Map a control use outside the partition to the start
+                // node. This corresponds to the outside predecessors of the
+                // top node and the use of the old start by constant,
+                // dynamic constant, parameter, and undef nodes.
+                NodeID::new(0)
+            }
+        };
+
         // Add the nodes from the partition.
         let mut select_top_phi_inputs = vec![];
         for id in partition.iter() {
-            let convert_id = |old| {
-                if let Some(new) = old_to_new_id.get(&old) {
-                    // Map a use inside the partition to its new ID in the
-                    // outlined function.
-                    *new
-                } else if let Some(idx) = outside_id_to_param_idx.get(&old) {
-                    // Map a data use outside the partition to the ID of the
-                    // corresponding parameter node.
-                    NodeID::new(idx + 1)
-                } else {
-                    // Map a control use outside the partition to the start
-                    // node. This corresponds to the outside predecessors of the
-                    // top node and the use of the old start by constant,
-                    // dynamic constant, parameter, and undef nodes.
-                    NodeID::new(0)
-                }
-            };
-
             let mut node = edit.get_node(*id).clone();
             if let Node::Phi { control, data } = &mut node
                 && *control == top_node
@@ -372,7 +372,7 @@ pub fn outline(
                     if dom_return_values.contains(inside_id) {
                         // If this outside used value dominates this return,
                         // then return the value itself.
-                        *inside_id
+                        convert_id(*inside_id)
                     } else {
                         // If not, then return an Undef. Since this value
                         // doesn't dominate this return, it can't be used on
@@ -408,7 +408,7 @@ pub fn outline(
 
             // Return the return product.
             outlined.nodes.push(Node::Return {
-                control: *exit,
+                control: convert_id(*exit),
                 data: construct_id,
             });
         }
@@ -558,7 +558,7 @@ pub fn outline(
 }
 
 /*
- * Just outlines all of a function accept the entry and return. Minimum work
+ * Just outlines all of a function except the entry and return. Minimum work
  * needed to cause runtime Rust code to be generated as necessary.
  */
 pub fn dumb_outline(
@@ -568,7 +568,9 @@ pub fn dumb_outline(
     dom: &DomTree,
     to_be_function_id: FunctionID,
 ) -> Option<Function> {
-    collapse_returns(editor);
+    if !contains_between_control_flow(editor.func()) {
+        return None;
+    }
     let partition = editor
         .node_ids()
         .filter(|id| {