Merge fbf0638 into f19344c

Author: vezenovm

compiler/noirc_evaluator/src/ssa/opt/mem2reg.rs

@@ -286,19 +286,19 @@ impl<'f> PerFunctionContext<'f> {
                 } else {
                     references.mark_value_used(address, self.inserter.function);
 
-                    let expression = if let Some(expression) = references.expressions.get(&result) {
-                        expression.clone()
-                    } else {
-                        references.expressions.insert(result, Expression::Other(result));
-                        Expression::Other(result)
-                    };
-                    if let Some(aliases) = references.aliases.get_mut(&expression) {
+                    let expression =
+                        references.expressions.entry(result).or_insert(Expression::Other(result));
+                    // Make sure this load result is marked an alias to itself
+                    if let Some(aliases) = references.aliases.get_mut(expression) {
+                        // If we have an alias set, add to the set
                         aliases.insert(result);
                     } else {
+                        // Otherwise, create a new alias set containing just the load result
                         references
                             .aliases
                             .insert(Expression::Other(result), AliasSet::known(result));
                     }
+                    // Mark that we know a load result is equivalent to the address of a load.
                     references.set_known_value(result, address);
 
                     self.last_loads.insert(address, (instruction, block_id));