Some Cava optimization

• Optimize Cava's CPU schedule.
• Add fork-fusion pass for fusing unrelated but adjacent fork-joins.
• Add intrinsic functions to math expressions.
• Add print pass for debugging schedules.
• Avoid some edges in dot output to help little xdot out.
• TODO: need more relaxed bounds for forkify to parallelize demosaic.

hercules_opt/src/delete_uncalled.rs

@@ -50,6 +50,11 @@ pub fn delete_uncalled(
     // that all nodes in all functions will be mutable, so panic if any
     // edit fails.
     for editor in editors.iter_mut() {
+        // Don't make edits to dead functions as they may include calls to dead functions
+        if new_idx[editor.func_id().idx()].is_none() {
+            continue;
+        }
+
         let callsites: Vec<_> = editor
             .node_ids()
             .filter(|id| editor.func().nodes[id.idx()].is_call())