Merge pull request #3721 from lrytz/t7852

SI-7852 for GenBCode

4 files changed, 38 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 1cea4bedda..0da66d43f7 100644
--- a/src/compiler/scala/tools/nsc/backend/icode/GenICode.scala
+++ b/src/compiler/scala/tools/nsc/backend/icode/GenICode.scala
@@ -13,13 +13,12 @@ import scala.collection.{ mutable, immutable }
 import scala.collection.mutable.{ ListBuffer, Buffer }
 import scala.tools.nsc.symtab._
 import scala.annotation.switch
-import PartialFunction._
 
 /**
  *  @author  Iulian Dragos
  *  @version 1.0
  */
-abstract class GenICode extends SubComponent  {
+abstract class GenICode extends SubComponent {
   import global._
   import icodes._
   import icodes.opcodes._
@@ -30,6 +29,9 @@ abstract class GenICode extends SubComponent  {
   }
   import platform.isMaybeBoxed
 
+  private val bCodeICodeCommon: jvm.BCodeICodeCommon[global.type] = new jvm.BCodeICodeCommon(global)
+  import bCodeICodeCommon._
+
   val phaseName = "icode"
 
   override def newPhase(prev: Phase) = new ICodePhase(prev)
@@ -1326,15 +1328,6 @@ abstract class GenICode extends SubComponent  {
         List(tree)
     }
 
-    /** Some useful equality helpers.
-     */
-    def isNull(t: Tree) = cond(t) { case Literal(Constant(null)) => true }
-    def isLiteral(t: Tree) = cond(t) { case Literal(_) => true }
-    def isNonNullExpr(t: Tree) = isLiteral(t) || ((t.symbol ne null) && t.symbol.isModule)
-
-    /* If l or r is constant null, returns the other ; otherwise null */
-    def ifOneIsNull(l: Tree, r: Tree) = if (isNull(l)) r else if (isNull(r)) l else null
-
     /**
      * Find the label denoted by `lsym` and enter it in context `ctx`.
      *
diff --git a/src/compiler/scala/tools/nsc/backend/jvm/BCodeBodyBuilder.scala b/src/compiler/scala/tools/nsc/backend/jvm/BCodeBodyBuilder.scala
index 53142fbd87..92ebe5027a 100644
--- a/src/compiler/scala/tools/nsc/backend/jvm/BCodeBodyBuilder.scala
+++ b/src/compiler/scala/tools/nsc/backend/jvm/BCodeBodyBuilder.scala
@@ -23,6 +23,7 @@ import scala.tools.asm
 abstract class BCodeBodyBuilder extends BCodeSkelBuilder {
   import global._
   import definitions._
+  import bCodeICodeCommon._
 
   /*
    * Functionality to build the body of ASM MethodNode, except for `synchronized` and `try` expressions.
@@ -1020,17 +1021,6 @@ abstract class BCodeBodyBuilder extends BCodeSkelBuilder {
         tree :: Nil
     }
 
-    /* Some useful equality helpers. */
-    def isNull(t: Tree) = {
-      t match {
-        case Literal(Constant(null)) => true
-        case _ => false
-      }
-    }
-
-    /* If l or r is constant null, returns the other ; otherwise null */
-    def ifOneIsNull(l: Tree, r: Tree) = if (isNull(l)) r else if (isNull(r)) l else null
-
     /* Emit code to compare the two top-most stack values using the 'op' operator. */
     private def genCJUMP(success: asm.Label, failure: asm.Label, op: TestOp, tk: BType) {
       if (tk.isIntSizedType) { // BOOL, BYTE, CHAR, SHORT, or INT
@@ -1200,6 +1190,12 @@ abstract class BCodeBodyBuilder extends BCodeSkelBuilder {
           // expr == null -> expr eq null
           genLoad(l, ObjectReference)
           genCZJUMP(success, failure, icodes.EQ, ObjectReference)
+        } else if (isNonNullExpr(l)) {
+          // SI-7852 Avoid null check if L is statically non-null.
+          genLoad(l, ObjectReference)
+          genLoad(r, ObjectReference)
+          genCallMethod(Object_equals, icodes.opcodes.Dynamic)
+          genCZJUMP(success, failure, icodes.NE, BOOL)
         } else {
           // l == r -> if (l eq null) r eq null else l.equals(r)
           val eqEqTempLocal = locals.makeLocal(AnyRefReference, nme.EQEQ_LOCAL_VAR.toString)
diff --git a/src/compiler/scala/tools/nsc/backend/jvm/BCodeGlue.scala b/src/compiler/scala/tools/nsc/backend/jvm/BCodeGlue.scala
index cc3265c5f9..aa7e73a36b 100644
--- a/src/compiler/scala/tools/nsc/backend/jvm/BCodeGlue.scala
+++ b/src/compiler/scala/tools/nsc/backend/jvm/BCodeGlue.scala
@@ -22,6 +22,8 @@ abstract class BCodeGlue extends SubComponent {
 
   import global._
 
+  protected val bCodeICodeCommon: BCodeICodeCommon[global.type] = new BCodeICodeCommon(global)
+
   object BType {
 
     import global.chrs
diff --git a/src/compiler/scala/tools/nsc/backend/jvm/BCodeICodeCommon.scala b/src/compiler/scala/tools/nsc/backend/jvm/BCodeICodeCommon.scala
new file mode 100644
index 0000000000..50d20921d5
--- /dev/null
+++ b/src/compiler/scala/tools/nsc/backend/jvm/BCodeICodeCommon.scala
@@ -0,0 +1,25 @@
+/* NSC -- new Scala compiler
+ * Copyright 2005-2014 LAMP/EPFL
+ * @author  Martin Odersky
+ */
+
+package scala.tools.nsc.backend.jvm
+
+import scala.tools.nsc.Global
+import PartialFunction._
+
+/**
+ * This trait contains code shared between GenBCode and GenICode that depends on types defined in
+ * the compiler cake (Global).
+ */
+final class BCodeICodeCommon[G <: Global](val global: G) {
+  import global._
+
+  /** Some useful equality helpers. */
+  def isNull(t: Tree) = cond(t) { case Literal(Constant(null)) => true }
+  def isLiteral(t: Tree) = cond(t) { case Literal(_) => true }
+  def isNonNullExpr(t: Tree) = isLiteral(t) || ((t.symbol ne null) && t.symbol.isModule)
+
+  /** If l or r is constant null, returns the other ; otherwise null */
+  def ifOneIsNull(l: Tree, r: Tree) = if (isNull(l)) r else if (isNull(r)) l else null
+}