Made hashCode a method on Type to avoid megamorphic dispatch

profiling data shows that accessing the hashCode field has a cost of about 10% of fully hot running times. We speculate that it's megamorphic dispatch which is costing us this much.
Rewrote code so that UniqueType is not an abstract base class with the hashCode field.

Also removed fingerPrinting bloom filter on findMember because it caused complexity and did not gain us anything accdoring to the tests.

Made TypeVar an abstract case class to avoid extractor calls in TypeMap.

1 files changed, 10 insertions, 15 deletions

diff --git a/src/compiler/scala/tools/nsc/typechecker/Typers.scala b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
index 4564cdf4f1..ff951a0436 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Typers.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
@@ -4679,8 +4679,6 @@ trait Typers extends Modes with Adaptations with Tags {
           errorContainer = tree
         }
 
-        val fingerPrint: Long = name.fingerPrint
-
         var defSym: Symbol = tree.symbol  // the directly found symbol
         var pre: Type = NoPrefix          // the prefix type of defSym, if a class member
         var qual: Tree = EmptyTree        // the qualifier tree if transformed tree is a select
@@ -4718,10 +4716,7 @@ trait Typers extends Modes with Adaptations with Tags {
           var cx = startingIdentContext
           while (defSym == NoSymbol && cx != NoContext && (cx.scope ne null)) { // cx.scope eq null arises during FixInvalidSyms in Duplicators
             pre = cx.enclClass.prefix
-            defEntry = {
-                val scope = cx.scope
-                if ((fingerPrint & scope.fingerPrints) != 0) scope.lookupEntry(name) else null
-              }
+            defEntry = cx.scope.lookupEntry(name)
             if ((defEntry ne null) && qualifies(defEntry.sym)) {
               // Right here is where SI-1987, overloading in package objects, can be
               // seen to go wrong. There is an overloaded symbol, but when referring
@@ -5069,7 +5064,7 @@ trait Typers extends Modes with Adaptations with Tags {
 
         treeCopy.Try(tree, block1, catches1, finalizer1) setType owntype
       }
-      
+
       def typedThrow(tree: Throw) = {
         val expr1 = typed(tree.expr, EXPRmode | BYVALmode, ThrowableClass.tpe)
         treeCopy.Throw(tree, expr1) setType NothingClass.tpe
@@ -5112,7 +5107,7 @@ trait Typers extends Modes with Adaptations with Tags {
               case _ =>
                 setError(tree)
             }
-            
+
           case _ =>
             val tptTyped = typedType(tpt, mode)
             val exprTyped = typed(expr, onlyStickyModes(mode), tptTyped.tpe.deconst)
@@ -5134,7 +5129,7 @@ trait Typers extends Modes with Adaptations with Tags {
               treeTyped setType tptTyped.tpe
         }
       }
-      
+
       def typedTypeApply(tree: TypeApply) = {
         val fun = tree.fun
         val args = tree.args
@@ -5206,11 +5201,11 @@ trait Typers extends Modes with Adaptations with Tags {
       }
 
       def typedSelectFromTypeTree(tree: SelectFromTypeTree) = {
-        val qual1 = typedType(tree.qualifier, mode) 
-        if (qual1.tpe.isVolatile) TypeSelectionFromVolatileTypeError(tree, qual1) 
+        val qual1 = typedType(tree.qualifier, mode)
+        if (qual1.tpe.isVolatile) TypeSelectionFromVolatileTypeError(tree, qual1)
         else typedSelect(tree, qual1, tree.name)
       }
-      
+
       def typedTypeBoundsTree(tree: TypeBoundsTree) = {
         val lo1 = typedType(tree.lo, mode)
         val hi1 = typedType(tree.hi, mode)
@@ -5250,7 +5245,7 @@ trait Typers extends Modes with Adaptations with Tags {
 
         case tree: TypeTree =>
           typedTypeTree(tree)
-         
+
         case tree: Literal =>
           typedLiteral(tree)
 
@@ -5292,7 +5287,7 @@ trait Typers extends Modes with Adaptations with Tags {
 
         case tree: New =>
           typedNew(tree)
-          
+
         case Assign(lhs, rhs) =>
           typedAssign(lhs, rhs)
 
@@ -5368,7 +5363,7 @@ trait Typers extends Modes with Adaptations with Tags {
         case tree: ReferenceToBoxed =>
           typedReferenceToBoxed(tree)
 
-        case tree: TypeTreeWithDeferredRefCheck => 
+        case tree: TypeTreeWithDeferredRefCheck =>
           tree // TODO: should we re-type the wrapped tree? then we need to change TypeTreeWithDeferredRefCheck's representation to include the wrapped tree explicitly (instead of in its closure)
 
         case tree: Import =>