Merge pull request #3449 from retronym/topic/opt11

Another grab bag of compiler optimizations

6 files changed, 49 insertions, 22 deletions

diff --git a/src/compiler/scala/tools/nsc/backend/icode/GenICode.scala b/src/compiler/scala/tools/nsc/backend/icode/GenICode.scala
index 9ba38b021d..b650cdfa09 100644
--- a/src/compiler/scala/tools/nsc/backend/icode/GenICode.scala
+++ b/src/compiler/scala/tools/nsc/backend/icode/GenICode.scala
@@ -46,8 +46,10 @@ abstract class GenICode extends SubComponent  {
     var unit: CompilationUnit = NoCompilationUnit
 
     override def run() {
-      scalaPrimitives.init()
-      classes.clear()
+      if (!settings.isBCodeActive) {
+        scalaPrimitives.init()
+        classes.clear()
+      }
       super.run()
     }
 
diff --git a/src/compiler/scala/tools/nsc/backend/icode/Members.scala b/src/compiler/scala/tools/nsc/backend/icode/Members.scala
index 267fa15312..64146585e5 100644
--- a/src/compiler/scala/tools/nsc/backend/icode/Members.scala
+++ b/src/compiler/scala/tools/nsc/backend/icode/Members.scala
@@ -21,7 +21,7 @@ trait Members {
 
   import global._
 
-  object NoCode extends Code(null, "NoCode") {
+  object NoCode extends Code(null, TermName("NoCode")) {
     override def blocksList: List[BasicBlock] = Nil
   }
 
@@ -29,8 +29,8 @@ trait Members {
    * This class represents the intermediate code of a method or
    * other multi-block piece of code, like exception handlers.
    */
-  class Code(method: IMethod, name: String) {
-    def this(method: IMethod) = this(method, method.symbol.decodedName.toString.intern)
+  class Code(method: IMethod, name: Name) {
+    def this(method: IMethod) = this(method, method.symbol.name)
     /** The set of all blocks */
     val blocks = mutable.ListBuffer[BasicBlock]()
 
@@ -82,7 +82,7 @@ trait Members {
     }
 
     /** This methods returns a string representation of the ICode */
-    override def toString = "ICode '" + name + "'"
+    override def toString = "ICode '" + name.decoded + "'"
 
     /* Compute a unique new label */
     def nextLabel: Int = {
diff --git a/src/compiler/scala/tools/nsc/transform/Erasure.scala b/src/compiler/scala/tools/nsc/transform/Erasure.scala
index a60310f900..ccfddab94a 100644
--- a/src/compiler/scala/tools/nsc/transform/Erasure.scala
+++ b/src/compiler/scala/tools/nsc/transform/Erasure.scala
@@ -92,11 +92,22 @@ abstract class Erasure extends AddInterfaces
   // more rigorous way up front rather than catching it after the fact,
   // but that will be more involved.
   private def dotCleanup(sig: String): String = {
+    // OPT 50% of time in generic signatures (~1% of compile time) was in this method, hence the imperative rewrite.
     var last: Char = '\u0000'
-    sig map {
-      case '.' if last != '>' => last = '.' ; '$'
-      case ch                 => last = ch ; ch
+    var i = 0
+    val len = sig.length
+    val copy: Array[Char] = sig.toCharArray
+    var changed = false
+    while (i < sig.length) {
+      val ch = copy(i)
+      if (ch == '.' && last != '>') {
+         copy(i) = '$'
+         changed = true
+      }
+      last = ch
+      i += 1
     }
+    if (changed) new String(copy) else sig
   }
 
   /** This object is only used for sanity testing when -check:genjvm is set.
diff --git a/src/compiler/scala/tools/nsc/transform/UnCurry.scala b/src/compiler/scala/tools/nsc/transform/UnCurry.scala
index e193cf3de2..e7ea686bc8 100644
--- a/src/compiler/scala/tools/nsc/transform/UnCurry.scala
+++ b/src/compiler/scala/tools/nsc/transform/UnCurry.scala
@@ -105,12 +105,11 @@ abstract class UnCurry extends InfoTransform
      */
     def isByNameRef(tree: Tree) = (
          tree.isTerm
-      && !byNameArgs(tree)
       && (tree.symbol ne null)
       && (isByName(tree.symbol))
+      && !byNameArgs(tree)
     )
 
-
 // ------- Handling non-local returns -------------------------------------------------
 
     /** The type of a non-local return expression with given argument type */
diff --git a/src/reflect/scala/reflect/internal/Names.scala b/src/reflect/scala/reflect/internal/Names.scala
index 4075653674..73ce59feb2 100644
--- a/src/reflect/scala/reflect/internal/Names.scala
+++ b/src/reflect/scala/reflect/internal/Names.scala
@@ -345,6 +345,13 @@ trait Names extends api.Names {
         i += 1
       i == prefix.length
     }
+    final def startsWith(prefix: String, start: Int): Boolean = {
+      var i = 0
+      while (i < prefix.length && start + i < len &&
+             chrs(index + start + i) == prefix.charAt(i))
+        i += 1
+      i == prefix.length
+    }
 
     /** Does this name end with suffix? */
     final def endsWith(suffix: Name): Boolean = endsWith(suffix, len)
@@ -357,6 +364,13 @@ trait Names extends api.Names {
         i += 1
       i > suffix.length
     }
+    final def endsWith(suffix: String, end: Int): Boolean = {
+      var i = 1
+      while (i <= suffix.length && i <= end &&
+             chrs(index + end - i) == suffix.charAt(suffix.length - i))
+        i += 1
+      i > suffix.length
+    }
 
     final def containsName(subname: String): Boolean = containsName(newTermName(subname))
     final def containsName(subname: Name): Boolean = {
@@ -382,9 +396,9 @@ trait Names extends api.Names {
     final def startChar: Char                   = this charAt 0
     final def endChar: Char                     = this charAt len - 1
     final def startsWith(char: Char): Boolean   = len > 0 && startChar == char
-    final def startsWith(name: String): Boolean = startsWith(newTermName(name))
+    final def startsWith(name: String): Boolean = startsWith(name, 0)
     final def endsWith(char: Char): Boolean     = len > 0 && endChar == char
-    final def endsWith(name: String): Boolean   = endsWith(newTermName(name))
+    final def endsWith(name: String): Boolean   = endsWith(name, len)
 
     /** Rewrite the confusing failure indication via result == length to
      *  the normal failure indication via result == -1.
@@ -443,9 +457,10 @@ trait Names extends api.Names {
     }
 
     /** TODO - find some efficiency. */
-    def append(ch: Char)        = newName("" + this + ch)
-    def append(suffix: String)  = newName("" + this + suffix)
-    def append(suffix: Name)    = newName("" + this + suffix)
+    def append(ch: Char)        = newName(toString + ch)
+    def append(suffix: String)  = newName(toString + suffix)
+    def append(suffix: Name)    = newName(toString + suffix)
+    def append(separator: Char, suffix: Name) = newName(toString + separator + suffix)
     def prepend(prefix: String) = newName("" + prefix + this)
 
     def decodedName: ThisNameType = newName(decode)
@@ -463,7 +478,7 @@ trait Names extends api.Names {
    */
   final class NameOps[T <: Name](name: T) {
     import NameTransformer._
-    def stripSuffix(suffix: String): T = stripSuffix(suffix: TermName)
+    def stripSuffix(suffix: String): T = if (name endsWith suffix) dropRight(suffix.length) else name // OPT avoid creating a Name with `suffix`
     def stripSuffix(suffix: Name): T   = if (name endsWith suffix) dropRight(suffix.length) else name
     def take(n: Int): T                = name.subName(0, n).asInstanceOf[T]
     def drop(n: Int): T                = name.subName(n, name.length).asInstanceOf[T]
@@ -500,21 +515,21 @@ trait Names extends api.Names {
   /** TermName_S and TypeName_S have fields containing the string version of the name.
    *  TermName_R and TypeName_R recreate it each time toString is called.
    */
-  private class TermName_S(index0: Int, len0: Int, hash: Int, override val toString: String) extends TermName(index0, len0, hash) {
+  private final class TermName_S(index0: Int, len0: Int, hash: Int, override val toString: String) extends TermName(index0, len0, hash) {
     protected def createCompanionName(h: Int): TypeName = new TypeName_S(index, len, h, toString)
     override def newName(str: String): TermName = newTermNameCached(str)
   }
-  private class TypeName_S(index0: Int, len0: Int, hash: Int, override val toString: String) extends TypeName(index0, len0, hash) {
+  private final class TypeName_S(index0: Int, len0: Int, hash: Int, override val toString: String) extends TypeName(index0, len0, hash) {
     protected def createCompanionName(h: Int): TermName = new TermName_S(index, len, h, toString)
     override def newName(str: String): TypeName = newTypeNameCached(str)
   }
 
-  private class TermName_R(index0: Int, len0: Int, hash: Int) extends TermName(index0, len0, hash) {
+  private final class TermName_R(index0: Int, len0: Int, hash: Int) extends TermName(index0, len0, hash) {
     protected def createCompanionName(h: Int): TypeName = new TypeName_R(index, len, h)
     override def toString = new String(chrs, index, len)
   }
 
-  private class TypeName_R(index0: Int, len0: Int, hash: Int) extends TypeName(index0, len0, hash) {
+  private final class TypeName_R(index0: Int, len0: Int, hash: Int) extends TypeName(index0, len0, hash) {
     protected def createCompanionName(h: Int): TermName = new TermName_R(index, len, h)
     override def toString = new String(chrs, index, len)
   }
diff --git a/src/reflect/scala/reflect/internal/Symbols.scala b/src/reflect/scala/reflect/internal/Symbols.scala
index 26914fecc1..b8cd1e86d3 100644
--- a/src/reflect/scala/reflect/internal/Symbols.scala
+++ b/src/reflect/scala/reflect/internal/Symbols.scala
@@ -1102,7 +1102,7 @@ trait Symbols extends api.Symbols { self: SymbolTable =>
     private def fullNameInternal(separator: Char): Name = (
       if (isRoot || isRootPackage || this == NoSymbol) name
       else if (owner.isEffectiveRoot) name
-      else ((effectiveOwner.enclClass.fullNameAsName(separator) append separator): Name) append name
+      else effectiveOwner.enclClass.fullNameAsName(separator) append (separator, name)
     )
 
     def fullNameAsName(separator: Char): Name = fullNameInternal(separator).dropLocal