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Delegate null-check-then-equals to Objects.equals #132

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Delegate null-check-then-equals to Objects.equals #132

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19 changes: 2 additions & 17 deletions src/compiler/scala/tools/nsc/backend/jvm/BCodeBodyBuilder.scala
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Expand Up @@ -1584,25 +1584,10 @@ abstract class BCodeBodyBuilder extends BCodeSkelBuilder {
genCallMethod(Object_equals, InvokeStyle.Virtual, pos)
genCZJUMP(success, failure, TestOp.NE, BOOL, targetIfNoJump)
} else {
// l == r -> if (l eq null) r eq null else l.equals(r)
val eqEqTempLocal = locals.makeLocal(ObjectRef, nme.EQEQ_LOCAL_VAR.toString)
val lNull = new asm.Label
val lNonNull = new asm.Label

// l == r -> Objects.equals(l, r)
genLoad(l, ObjectRef)
genLoad(r, ObjectRef)
locals.store(eqEqTempLocal)
bc dup ObjectRef
genCZJUMP(lNull, lNonNull, TestOp.EQ, ObjectRef, targetIfNoJump = lNull)

markProgramPoint(lNull)
bc drop ObjectRef
locals.load(eqEqTempLocal)
genCZJUMP(success, failure, TestOp.EQ, ObjectRef, targetIfNoJump = lNonNull)

markProgramPoint(lNonNull)
locals.load(eqEqTempLocal)
genCallMethod(Object_equals, InvokeStyle.Virtual, pos)
genCallMethod(Objects_equals, InvokeStyle.Static, pos)
genCZJUMP(success, failure, TestOp.NE, BOOL, targetIfNoJump)
}
}
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8 changes: 5 additions & 3 deletions src/reflect/scala/reflect/internal/Definitions.scala
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Expand Up @@ -290,9 +290,10 @@ trait Definitions extends api.StandardDefinitions {
}

// top types
lazy val AnyClass = enterNewClass(ScalaPackageClass, tpnme.Any, Nil, ABSTRACT).markAllCompleted()
lazy val AnyRefClass = newAlias(ScalaPackageClass, tpnme.AnyRef, ObjectTpe).markAllCompleted()
lazy val ObjectClass = getRequiredClass("java.lang.Object")
lazy val AnyClass = enterNewClass(ScalaPackageClass, tpnme.Any, Nil, ABSTRACT).markAllCompleted()
lazy val AnyRefClass = newAlias(ScalaPackageClass, tpnme.AnyRef, ObjectTpe).markAllCompleted()
lazy val ObjectClass = getRequiredClass("java.lang.Object")
lazy val ObjectsModule = getRequiredModule("java.util.Objects")

// Cached types for core monomorphic classes
lazy val AnyRefTpe = AnyRefClass.tpe
Expand Down Expand Up @@ -1285,6 +1286,7 @@ trait Definitions extends api.StandardDefinitions {
def Object_equals = getMemberMethod(ObjectClass, nme.equals_)
def Object_hashCode = getMemberMethod(ObjectClass, nme.hashCode_)
def Object_toString = getMemberMethod(ObjectClass, nme.toString_)
def Objects_equals = getMemberMethod(ObjectsModule, nme.equals_)

// boxed classes
lazy val ObjectRefClass = requiredClass[scala.runtime.ObjectRef[_]]
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15 changes: 5 additions & 10 deletions test/junit/scala/tools/nsc/backend/jvm/BytecodeTest.scala
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Expand Up @@ -106,16 +106,11 @@ class BytecodeTest extends BytecodeTesting {
Label(7), Op(ICONST_2), Op(IRETURN)))

// t3: Array == is translated to reference equality, AnyRef == to null checks and equals
assertSameCode(getMethod(c, "t3"), List(
// Array ==
VarOp(ALOAD, 1), VarOp(ALOAD, 2), Jump(IF_ACMPEQ, Label(23)),
// AnyRef ==
VarOp(ALOAD, 2), VarOp(ALOAD, 1), VarOp(ASTORE, 3), Op(DUP), Jump(IFNONNULL, Label(14)),
Op(POP), VarOp(ALOAD, 3), Jump(IFNULL, Label(19)), Jump(GOTO, Label(23)),
Label(14), VarOp(ALOAD, 3), InvokeVirtual("java/lang/Object", "equals", "(Ljava/lang/Object;)Z"), Jump(IFEQ, Label(23)),
Label(19), Op(ICONST_1), Jump(GOTO, Label(26)),
Label(23), Op(ICONST_0),
Label(26), Op(IRETURN)))
assertSameCode(getMethod(c, "t3"), List(
VarOp(ALOAD, 1), VarOp(ALOAD, 2), Jump(IF_ACMPEQ, Label(11)),
VarOp(ALOAD, 2), VarOp(ALOAD, 1),
Invoke(INVOKESTATIC, "java/util/Objects", "equals", "(Ljava/lang/Object;Ljava/lang/Object;)Z", itf = false),
Jump(IFEQ, Label(11)), Op(ICONST_1), Jump(GOTO, Label(14)), Label(11), Op(ICONST_0), Label(14), Op(IRETURN)))

val t4t5 = List(
VarOp(ALOAD, 1), Jump(IFNULL, Label(6)),
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