Misc performance improvements by eliminating stupid allocations

- Avoid closure creation in Position.
- Avoid creating debug string in SymDenotations
- Avoid creating Flag translation tables in pickle buffers

1 files changed, 21 insertions, 18 deletions

diff --git a/src/dotty/tools/dotc/core/pickling/PickleBuffer.scala b/src/dotty/tools/dotc/core/pickling/PickleBuffer.scala
index b44d7f292..72007758c 100644
--- a/src/dotty/tools/dotc/core/pickling/PickleBuffer.scala
+++ b/src/dotty/tools/dotc/core/pickling/PickleBuffer.scala
@@ -166,6 +166,27 @@ class PickleBuffer(data: Array[Byte], from: Int, to: Int) {
   def times[T](n: Int, op: ()=>T): List[T] =
     if (n == 0) List() else op() :: times(n-1, op)
 
+  /** Pickle = majorVersion_Nat minorVersion_Nat nbEntries_Nat {Entry}
+   *  Entry  = type_Nat length_Nat [actual entries]
+   *
+   *  Assumes that the ..Version_Nat are already consumed.
+   *
+   *  @return an array mapping entry numbers to locations in
+   *  the byte array where the entries start.
+   */
+  def createIndex: Array[Int] = {
+    val index = new Array[Int](readNat()) // nbEntries_Nat
+    for (i <- 0 until index.length) {
+      index(i) = readIndex
+      readByte() // skip type_Nat
+      readIndex = readNat() + readIndex // read length_Nat, jump to next entry
+    }
+    index
+  }
+}
+
+object PickleBuffer {
+
   private final val ScalaFlagEnd = 48
   private final val ChunkBits = 8
   private final val ChunkSize = 1 << ChunkBits
@@ -261,24 +282,6 @@ class PickleBuffer(data: Array[Byte], from: Int, to: Int) {
     (chunkMap(termMap), chunkMap(typeMap))
   }
 
-  /** Pickle = majorVersion_Nat minorVersion_Nat nbEntries_Nat {Entry}
-   *  Entry  = type_Nat length_Nat [actual entries]
-   *
-   *  Assumes that the ..Version_Nat are already consumed.
-   *
-   *  @return an array mapping entry numbers to locations in
-   *  the byte array where the entries start.
-   */
-  def createIndex: Array[Int] = {
-    val index = new Array[Int](readNat()) // nbEntries_Nat
-    for (i <- 0 until index.length) {
-      index(i) = readIndex
-      readByte() // skip type_Nat
-      readIndex = readNat() + readIndex // read length_Nat, jump to next entry
-    }
-    index
-  }
-
   def unpickleScalaFlags(sflags: Long, isType: Boolean): FlagSet = {
     val map: FlagMap = if (isType) scalaTypeFlagMap else scalaTermFlagMap
     val shift = ChunkBits