Eliminate allocations in TypeMap.

2 files changed, 8 insertions, 3 deletions

diff --git a/src/reflect/scala/reflect/api/Trees.scala b/src/reflect/scala/reflect/api/Trees.scala
index cfa6315797..94226ae866 100644
--- a/src/reflect/scala/reflect/api/Trees.scala
+++ b/src/reflect/scala/reflect/api/Trees.scala
@@ -2921,7 +2921,7 @@ trait Trees { self: Universe =>
     def transform(tree: Tree): Tree = itransform(this, tree)
 
     /** Transforms a list of trees. */
-    def transformTrees(trees: List[Tree]): List[Tree] = trees mapConserve (transform(_))
+    def transformTrees(trees: List[Tree]): List[Tree] = trees mapConserve transform
 
     /** Transforms a `Template`. */
     def transformTemplate(tree: Template): Template =
diff --git a/src/reflect/scala/reflect/internal/Types.scala b/src/reflect/scala/reflect/internal/Types.scala
index 599bc2e264..b706ef8abe 100644
--- a/src/reflect/scala/reflect/internal/Types.scala
+++ b/src/reflect/scala/reflect/internal/Types.scala
@@ -4082,8 +4082,13 @@ trait Types extends api.Types { self: SymbolTable =>
     /** Called by mapOver to determine whether the original symbols can
      *  be returned, or whether they must be cloned.  Overridden in VariantTypeMap.
      */
-    protected def noChangeToSymbols(origSyms: List[Symbol]) =
-      origSyms forall (sym => sym.info eq this(sym.info))
+    protected def noChangeToSymbols(origSyms: List[Symbol]): Boolean = {
+      @tailrec def loop(syms: List[Symbol]): Boolean = syms match {
+        case Nil     => true
+        case x :: xs => (x.info eq this(x.info)) && loop(xs)
+      }
+      loop(origSyms)
+    }
 
     /** Map this function over given scope */
     def mapOver(scope: Scope): Scope = {