perf(es/minifier): less clone

Author: bvanjoi

crates/swc_ecma_minifier/src/compress/optimize/unused.rs

@@ -107,21 +107,19 @@ impl Optimizer<'_> {
 
     #[cfg_attr(feature = "debug", tracing::instrument(level = "debug", skip_all))]
     pub(super) fn drop_unused_vars(&mut self, name: &mut Pat, init: Option<&mut Expr>) {
-        if self
-            .ctx
-            .bit_ctx
-            .intersects(BitCtx::IsExported | BitCtx::InAsm)
-        {
+        if !self.options.unused && !self.options.side_effects {
             return;
         }
 
-        trace_op!("unused: drop_unused_vars({})", dump(&*name, false));
-
-        if !self.options.unused && !self.options.side_effects {
+        if self.ctx.bit_ctx.intersects(
+            BitCtx::IsExported
+                .union(BitCtx::InAsm)
+                .union(BitCtx::InVarDeclOfForInOrOfLoop),
+        ) {
             return;
         }
 
-        if self.ctx.bit_ctx.contains(BitCtx::InVarDeclOfForInOrOfLoop) {
+        if !name.is_ident() && init.is_none() {
             return;
         }
 
@@ -135,9 +133,7 @@ impl Optimizer<'_> {
             }
         }
 
-        if !name.is_ident() && init.is_none() {
-            return;
-        }
+        trace_op!("unused: drop_unused_vars({})", dump(&*name, false));
 
         self.take_pat_if_unused(name, init, true);
     }

crates/swc_ecma_usage_analyzer/src/analyzer/mod.rs

@@ -2,9 +2,7 @@ use ctx::BitContext;
 use rustc_hash::FxHashMap;
 use swc_common::SyntaxContext;
 use swc_ecma_ast::*;
-use swc_ecma_utils::{
-    find_pat_ids, ident::IdentLike, ExprCtx, ExprExt, IsEmpty, StmtExt, Type, Value,
-};
+use swc_ecma_utils::{find_pat_ids, ExprCtx, ExprExt, IsEmpty, StmtExt, Type, Value};
 use swc_ecma_visit::{noop_visit_type, Visit, VisitWith};
 use swc_timer::timer;
 
@@ -159,7 +157,7 @@ where
                 self.data.report_usage(self.ctx, i.clone());
                 self.data.var_or_default(i.clone()).mark_used_above_decl()
             }
-            self.data.var_or_default(i.clone()).mark_used_recursively();
+            self.data.var_or_default(i).mark_used_recursively();
             return;
         }
 
@@ -301,7 +299,7 @@ where
 
         if n.op == op!("=") {
             let left = match &n.left {
-                AssignTarget::Simple(left) => left.leftmost().map(Ident::to_id),
+                AssignTarget::Simple(left) => left.leftmost(),
                 AssignTarget::Pat(..) => None,
             };
 
@@ -319,7 +317,7 @@ where
                         v = Some(self.data.var_or_default(left.to_id()));
                     }
 
-                    v.as_mut().unwrap().add_infects_to(id.clone());
+                    v.as_mut().unwrap().add_infects_to(id);
                 }
             }
         }
@@ -800,7 +798,7 @@ where
                     v = Some(self.data.var_or_default(n.ident.to_id()));
                 }
 
-                v.as_mut().unwrap().add_infects_to(id.clone());
+                v.as_mut().unwrap().add_infects_to(id);
             }
         }
     }
@@ -1390,7 +1388,7 @@ where
                         v = Some(self.data.var_or_default(var.to_id()));
                     }
 
-                    v.as_mut().unwrap().add_infects_to(id.clone());
+                    v.as_mut().unwrap().add_infects_to(id);
                 }
             }
         }