Merge pull request #3763 from adriaanm/revert-3760v2.11.1

Revert #3760

10 files changed, 7 insertions, 61 deletions

diff --git a/src/compiler/scala/tools/nsc/backend/opt/ClosureElimination.scala b/src/compiler/scala/tools/nsc/backend/opt/ClosureElimination.scala
index 0b943360de..c49f23852f 100644
--- a/src/compiler/scala/tools/nsc/backend/opt/ClosureElimination.scala
+++ b/src/compiler/scala/tools/nsc/backend/opt/ClosureElimination.scala
@@ -56,10 +56,11 @@ abstract class ClosureElimination extends SubComponent {
       case (BOX(t1), UNBOX(t2)) if (t1 == t2) =>
         Some(Nil)
 
-      // Can't eliminate (LOAD_FIELD, DROP) without eliding side effects:
-      //  - static class initialization
-      //  - NPE if the receiver is null
-      // We could replace the LOAD/DROP with a null check to preserve semantics.
+      case (LOAD_FIELD(sym, isStatic), DROP(_)) if !sym.hasAnnotation(definitions.VolatileAttr) =>
+        if (isStatic)
+          Some(Nil)
+        else
+          Some(DROP(REFERENCE(definitions.ObjectClass)) :: Nil)
 
       case _ => None
     }
diff --git a/src/compiler/scala/tools/nsc/backend/opt/DeadCodeElimination.scala b/src/compiler/scala/tools/nsc/backend/opt/DeadCodeElimination.scala
index 245894a4af..90c37ba0b3 100644
--- a/src/compiler/scala/tools/nsc/backend/opt/DeadCodeElimination.scala
+++ b/src/compiler/scala/tools/nsc/backend/opt/DeadCodeElimination.scala
@@ -167,9 +167,9 @@ abstract class DeadCodeElimination extends SubComponent {
               set += idx
               localStores(key) = set
 
-            case RETURN(_) | JUMP(_) | CJUMP(_, _, _, _) | CZJUMP(_, _, _, _) | STORE_FIELD(_, _) | LOAD_FIELD(_, _) | // Why LOAD_FIELD? It can NPE!
+            case RETURN(_) | JUMP(_) | CJUMP(_, _, _, _) | CZJUMP(_, _, _, _) | STORE_FIELD(_, _) |
                  THROW(_)   | LOAD_ARRAY_ITEM(_) | STORE_ARRAY_ITEM(_) | SCOPE_ENTER(_) | SCOPE_EXIT(_) | STORE_THIS(_) |
-                 LOAD_EXCEPTION(_) | SWITCH(_, _) | MONITOR_ENTER() | MONITOR_EXIT() | CHECK_CAST(_) | CREATE_ARRAY(_, _) =>
+                 LOAD_EXCEPTION(_) | SWITCH(_, _) | MONITOR_ENTER() | MONITOR_EXIT() | CHECK_CAST(_) =>
               moveToWorkList()
 
             case CALL_METHOD(m1, _) if isSideEffecting(m1) =>
@@ -193,8 +193,6 @@ abstract class DeadCodeElimination extends SubComponent {
               moveToWorkListIf(necessary)
             case LOAD_MODULE(sym) if isLoadNeeded(sym) =>
               moveToWorkList() // SI-4859 Module initialization might side-effect.
-            case CALL_PRIMITIVE(Arithmetic(DIV | REM, INT | LONG) | ArrayLength(_)) =>
-              moveToWorkList() // SI-8601 Might divide by zero
             case _ => ()
               moveToWorkListIf(cond = false)
           }
diff --git a/test/files/run/t8601.flags b/test/files/run/t8601.flags
deleted file mode 100644
index 1182725e86..0000000000
--- a/test/files/run/t8601.flags
+++ /dev/null
@@ -1 +0,0 @@
--optimize
\ No newline at end of file
diff --git a/test/files/run/t8601.scala b/test/files/run/t8601.scala
deleted file mode 100644
index e1afc23cc4..0000000000
--- a/test/files/run/t8601.scala
+++ /dev/null
@@ -1,15 +0,0 @@
-object Test {
-  def idiv(x: Int): Unit = x / 0
-  def ldiv(x: Long): Unit = x / 0
-  def irem(x: Int): Unit = x % 0
-  def lrem(x: Long): Unit = x % 0
-
-  def check(x: => Any) = try { x; sys.error("failed to throw divide by zero!") } catch { case _: ArithmeticException => }
-
-  def main(args: Array[String]) {
-    check(idiv(1))
-    check(ldiv(1L))
-    check(irem(1))
-    check(lrem(1L))
-  }
-}
diff --git a/test/files/run/t8601b.flags b/test/files/run/t8601b.flags
deleted file mode 100644
index 1182725e86..0000000000
--- a/test/files/run/t8601b.flags
+++ /dev/null
@@ -1 +0,0 @@
--optimize
\ No newline at end of file
diff --git a/test/files/run/t8601b.scala b/test/files/run/t8601b.scala
deleted file mode 100644
index 9c37ce33d6..0000000000
--- a/test/files/run/t8601b.scala
+++ /dev/null
@@ -1,14 +0,0 @@
-object Test {
-  def len(x: Array[String]): Unit = x.length
-  def load(x: Array[String]): Unit = x(0)
-  def newarray(i: Int): Unit = new Array[Int](i)
-
-  def check(x: => Any) = try { x; sys.error("failed to throw NPE!") } catch { case _: NullPointerException => }
-  def checkNegSize(x: => Any) = try { x; sys.error("failed to throw NegativeArraySizeException!") } catch { case _: NegativeArraySizeException => }
-
-  def main(args: Array[String]) {
-    check(len(null)) // bug: did not NPE
-    check(load(null))
-    checkNegSize(newarray(-1))
-  }
-}
diff --git a/test/files/run/t8601c.flags b/test/files/run/t8601c.flags
deleted file mode 100644
index 1182725e86..0000000000
--- a/test/files/run/t8601c.flags
+++ /dev/null
@@ -1 +0,0 @@
--optimize
\ No newline at end of file
diff --git a/test/files/run/t8601c.scala b/test/files/run/t8601c.scala
deleted file mode 100644
index c487d6825e..0000000000
--- a/test/files/run/t8601c.scala
+++ /dev/null
@@ -1,12 +0,0 @@
-object Test {
-  def loadField(x: scala.runtime.IntRef): Unit = x.elem
-  def storeField(x: scala.runtime.IntRef): Unit = x.elem = 42
-
-  def check(x: => Any) = try { x; sys.error("failed to throw NPE!") } catch { case _: NullPointerException => }
-
-  def main(args: Array[String]) {
-    check(loadField(null)) // bug: did not NPE under -Ydead-code
-    check(storeField(null))
-
-  }
-}
diff --git a/test/files/run/t8601d.flags b/test/files/run/t8601d.flags
deleted file mode 100644
index 1182725e86..0000000000
--- a/test/files/run/t8601d.flags
+++ /dev/null
@@ -1 +0,0 @@
--optimize
\ No newline at end of file
diff --git a/test/files/run/t8601d.scala b/test/files/run/t8601d.scala
deleted file mode 100644
index ac89963d67..0000000000
--- a/test/files/run/t8601d.scala
+++ /dev/null
@@ -1,8 +0,0 @@
-object Test {
-  def monitor(x: AnyRef): Unit = {x.synchronized(()); ()}
-  def check(x: => Any) = try { x; sys.error("failed to throw NPE") } catch { case _: NullPointerException => }
-
-  def main(args: Array[String]) {
-    check(monitor(null))
-  }
-}