0.NewSource.scala

case class CC(a: Int, b: Object)
object Lists{
  def foo(x: Any): Int = {
    val (a, b) = x match {
      case CC(s @ 1, CC(t, _)) =>
        (s , 2)
      case _ => (42, 43)
    }
    a + b
  }
  def booleans(a: Object) = {
    val (b1, b2) = (a.isInstanceOf[CC], a.isInstanceOf[List[Int]])
    (b1, b2) match {
      case (true, true) => true
      case (false, false) => true
      case _ => false
    }
  }
 }

1.scalac.java

  /*
     * Unable to fully structure code
     * Enabled aggressive block sorting
     * Lifted jumps to return sites
     */
    public int foo(Object x) {
        var4_2 = x;
        if (!(var4_2 instanceof CC)) ** GOTO lbl-1000
        var5_3 = (CC)var4_2;
        var6_4 = var5_3.a();
        var7_5 = var5_3.b();
        if (1 == var6_4 && var7_5 instanceof CC) {
            var8_6 = new Tuple2.mcII.sp(1, 2);
        } else lbl-1000: // 2 sources:
        {
            var8_6 = new Tuple2.mcII.sp(42, 43);
        }
        var3_7 = var8_6;
        if (var3_7 == null) throw new MatchError((Object)var3_7);
        a = var3_7._1$mcI$sp();
        b = var3_7._2$mcI$sp();
        var2_11 = var11_10 = new Tuple2.mcII.sp(a, b);
        a = var2_11._1$mcI$sp();
        b = var2_11._2$mcI$sp();
        return a + b;
    }

    /*
     * Enabled force condition propagation
     * Lifted jumps to return sites
     */
    public boolean booleans(Object a) {
        boolean b2;
        boolean b22;
        Tuple2.mcZZ.sp sp2 = new Tuple2.mcZZ.sp(a instanceof CC, a instanceof List);
        if (sp2 == null) throw new MatchError((Object)sp2);
        boolean b1 = sp2._1$mcZ$sp();
        Tuple2.mcZZ.sp sp3 = new Tuple2.mcZZ.sp(b1, b2 = sp2._2$mcZ$sp());
        Tuple2.mcZZ.sp sp4 = sp3;
        boolean b12 = sp4._1$mcZ$sp();
        Tuple2.mcZZ.sp sp5 = new Tuple2.mcZZ.sp(b12, b22 = sp4._2$mcZ$sp());
        if (sp5 != null) {
            boolean bl = sp5._1$mcZ$sp();
            boolean bl2 = sp5._2$mcZ$sp();
            if (bl && bl2) {
                return true;
            }
        }
        if (sp5 == null) return false;
        boolean bl = sp5._1$mcZ$sp();
        boolean bl3 = sp5._2$mcZ$sp();
        if (false != bl) return false;
        if (false != bl3) return false;
        return true;
    }

2.dotty.java

 public int foo(Object x) {
        var3_2 = x;
        if (!(var3_2 instanceof CC)) ** GOTO lbl-1000
        var4_3 = (CC)var3_2;
        var5_4 = CC$.MODULE$.unapply((CC)var3_2);
        s = var5_4._1();
        var7_6 = var5_4._2();
        if (1 != s) ** GOTO lbl-1000
        var8_7 = s;
        if (var7_6 instanceof CC) {
            var9_8 = (CC)var7_6;
            var10_9 = CC$.MODULE$.unapply((CC)var7_6);
            var11_10 = var10_9._2();
            v0 = Tuple2..MODULE$.apply((Object)BoxesRunTime.boxToInteger((int)1), (Object)BoxesRunTime.boxToInteger((int)2));
        } else lbl-1000: // 3 sources:
        {
            v0 = Tuple2..MODULE$.apply((Object)BoxesRunTime.boxToInteger((int)42), (Object)BoxesRunTime.boxToInteger((int)43));
        }
        var2_11 = v0;
        a = BoxesRunTime.unboxToInt((Object)var2_11._1());
        b = BoxesRunTime.unboxToInt((Object)var2_11._2());
        return a + b;
    }

    /*
     * Enabled force condition propagation
     * Lifted jumps to return sites
     */
    public boolean booleans(Object a) {
        Tuple2 tuple2 = Tuple2..MODULE$.apply((Object)BoxesRunTime.boxToBoolean((boolean)(a instanceof CC)), (Object)BoxesRunTime.boxToBoolean((boolean)(a instanceof List)));
        boolean b1 = BoxesRunTime.unboxToBoolean((Object)tuple2._1());
        boolean b2 = BoxesRunTime.unboxToBoolean((Object)tuple2._2());
        Tuple2 tuple22 = Tuple2..MODULE$.apply((Object)BoxesRunTime.boxToBoolean((boolean)b1), (Object)BoxesRunTime.boxToBoolean((boolean)b2));
        Option option = Tuple2..MODULE$.unapply(tuple22);
        if (option.isDefined()) {
            Tuple2 tuple23 = (Tuple2)option.get();
            boolean bl = BoxesRunTime.unboxToBoolean((Object)tuple23._1());
            boolean bl2 = BoxesRunTime.unboxToBoolean((Object)tuple23._2());
            if (bl) {
                boolean bl3 = bl;
                if (bl2) {
                    boolean bl4 = bl2;
                    return true;
                }
            }
        }
        Option option2 = Tuple2..MODULE$.unapply(tuple22);
        if (!option2.isDefined()) return false;
        Tuple2 tuple24 = (Tuple2)option2.get();
        boolean bl = BoxesRunTime.unboxToBoolean((Object)tuple24._1());
        boolean bl5 = BoxesRunTime.unboxToBoolean((Object)tuple24._2());
        if (bl) return false;
        boolean bl6 = bl;
        if (bl5) return false;
        boolean bl7 = bl5;
        return true;
    }

3.linker.java

    public int foo(Object x) {
        CC cC;
        int n = 0;
        int n2 = 0;
        if (x instanceof CC && 1 == (cC = (CC)x)._1() && cC._2() instanceof CC) {
            n = 1;
            n2 = 2;
        } else {
            n = 42;
            n2 = 43;
        }
        return n + n2;
    }

    public boolean booleans(Object a) {
        boolean bl = a instanceof CC;
        boolean bl2 = a instanceof List;
        if (bl && bl2 || !bl && !bl2) {
            return true;
        }
        return false;
    }

4.linker.bytecode

public int foo(java.lang.Object);
    Code:
       0: iconst_0
       1: istore_2
       2: iconst_0
       3: istore_3
       4: aload_1
       5: instanceof    #20                 // class CC
       8: ifeq          44
      11: aload_1
      12: checkcast     #20                 // class CC
      15: astore        4
      17: iconst_1
      18: aload         4
      20: invokevirtual #24                 // Method CC._1:()I
      23: if_icmpne     44
      26: aload         4
      28: invokevirtual #28                 // Method CC._2:()Ljava/lang/Object;
      31: instanceof    #20                 // class CC
      34: ifeq          44
      37: iconst_1
      38: istore_2
      39: iconst_2
      40: istore_3
      41: goto          50
      44: bipush        42
      46: istore_2
      47: bipush        43
      49: istore_3
      50: iload_2
      51: iload_3
      52: iadd
      53: ireturn

  public boolean booleans(java.lang.Object);
    Code:
       0: aload_1
       1: instanceof    #20                 // class CC
       4: istore_2
       5: aload_1
       6: instanceof    #34                 // class scala/collection/immutable/List
       9: istore_3
      10: iload_2
      11: ifeq          18
      14: iload_3
      15: ifne          26
      18: iload_2
      19: ifne          28
      22: iload_3
      23: ifne          28
      26: iconst_1
      27: ireturn
      28: iconst_0
      29: ireturn

5.scala2.12-Yopt:l:method.scala

 /*
     * Enabled force condition propagation
     * Lifted jumps to return sites
     */
    public int foo(Object x) {
        void b;
        int a;
        if (x instanceof CC) {
            CC cC = (CC)x;
            int n = cC.a();
            Object object = cC.b();
            if (1 == n && object instanceof CC) {
                return a + b;
            }
        }
        int n = 43;
        a = 42;
        return a + b;
    }

    public boolean booleans(Object a) {
        boolean bl = a instanceof List;
        boolean bl2 = a instanceof CC;
        boolean bl3 = true == bl2 && true == bl ? true : false == bl2 && false == bl;
        return bl3;
    }

6.scala2.12-Yopt:l:method.bytecode

 public int foo(java.lang.Object);
    Code:
       0: aload_1
       1: instanceof    #17                 // class CC
       4: ifeq          45
       7: aload_1
       8: checkcast     #17                 // class CC
      11: astore_2
      12: aload_2
      13: invokevirtual #21                 // Method CC.a:()I
      16: istore_3
      17: aload_2
      18: invokevirtual #25                 // Method CC.b:()Ljava/lang/Object;
      21: astore        4
      23: iconst_1
      24: iload_3
      25: if_icmpne     45
      28: aload         4
      30: instanceof    #17                 // class CC
      33: ifeq          45
      36: iconst_1
      37: iconst_2
      38: istore        6
      40: istore        5
      42: goto          53
      45: bipush        42
      47: bipush        43
      49: istore        6
      51: istore        5
      53: iload         5
      55: iload         6
      57: iadd
      58: ireturn

  public boolean booleans(java.lang.Object);
    Code:
       0: aload_1
       1: instanceof    #17                 // class CC
       4: aload_1
       5: instanceof    #32                 // class scala/collection/immutable/List
       8: istore        4
      10: istore_3
      11: iconst_1
      12: iload_3
      13: if_icmpne     27
      16: iconst_1
      17: iload         4
      19: if_icmpne     27
      22: iconst_1
      23: istore_2
      24: goto          45
      27: iconst_0
      28: iload_3
      29: if_icmpne     43
      32: iconst_0
      33: iload         4
      35: if_icmpne     43
      38: iconst_1
      39: istore_2
      40: goto          45
      43: iconst_0
      44: istore_2
      45: iload_2
      46: ireturn