diff options
6 files changed, 386 insertions, 47 deletions
diff --git a/src/compiler/scala/tools/nsc/backend/jvm/CoreBTypes.scala b/src/compiler/scala/tools/nsc/backend/jvm/CoreBTypes.scala index 79aa4308c5..0317e08d9e 100644 --- a/src/compiler/scala/tools/nsc/backend/jvm/CoreBTypes.scala +++ b/src/compiler/scala/tools/nsc/backend/jvm/CoreBTypes.scala @@ -119,6 +119,7 @@ class CoreBTypes[BTFS <: BTypesFromSymbols[_ <: Global]](val bTypes: BTFS) { lazy val jliMethodHandlesLookupRef : ClassBType = classBTypeFromSymbol(exitingPickler(rootMirror.getRequiredClass("java.lang.invoke.MethodHandles.Lookup"))) // didn't find a reliable non-stringly-typed way that works for inner classes in the backend lazy val srLambdaDeserializerRef : ClassBType = classBTypeFromSymbol(requiredModule[scala.runtime.LambdaDeserializer.type].moduleClass) lazy val srBoxesRunTimeRef : ClassBType = classBTypeFromSymbol(requiredClass[scala.runtime.BoxesRunTime]) + lazy val srBoxedUnitRef : ClassBType = classBTypeFromSymbol(requiredClass[scala.runtime.BoxedUnit]) lazy val hashMethodSym: Symbol = getMember(ScalaRunTimeModule, nme.hash_) @@ -202,6 +203,11 @@ trait CoreBTypesProxyGlobalIndependent[BTS <: BTypes] { def jliMethodHandlesRef : ClassBType def jliMethodHandlesLookupRef : ClassBType def srLambdaDeserializerRef : ClassBType + def srBoxesRunTimeRef : ClassBType + def srBoxedUnitRef : ClassBType + + def asmBoxTo : Map[BType, MethodNameAndType] + def asmUnboxTo: Map[BType, MethodNameAndType] } /** @@ -242,6 +248,7 @@ final class CoreBTypesProxy[BTFS <: BTypesFromSymbols[_ <: Global]](val bTypes: def jliMethodHandlesLookupRef : ClassBType = _coreBTypes.jliMethodHandlesLookupRef def srLambdaDeserializerRef : ClassBType = _coreBTypes.srLambdaDeserializerRef def srBoxesRunTimeRef : ClassBType = _coreBTypes.srBoxesRunTimeRef + def srBoxedUnitRef : ClassBType = _coreBTypes.srBoxedUnitRef def hashMethodSym: Symbol = _coreBTypes.hashMethodSym diff --git a/src/compiler/scala/tools/nsc/backend/jvm/analysis/BackendUtils.scala b/src/compiler/scala/tools/nsc/backend/jvm/analysis/BackendUtils.scala index 204c6a33ce..e4fdcdc542 100644 --- a/src/compiler/scala/tools/nsc/backend/jvm/analysis/BackendUtils.scala +++ b/src/compiler/scala/tools/nsc/backend/jvm/analysis/BackendUtils.scala @@ -7,6 +7,7 @@ import scala.tools.asm.{Opcodes, Handle, Type, Label} import scala.tools.asm.tree._ import scala.tools.asm.tree.analysis.{Frame, BasicInterpreter, Analyzer, Value} import scala.tools.nsc.backend.jvm.BTypes._ +import scala.tools.nsc.backend.jvm.opt.BytecodeUtils import scala.tools.nsc.backend.jvm.opt.BytecodeUtils._ import java.lang.invoke.LambdaMetafactory import scala.collection.mutable @@ -23,6 +24,7 @@ import scala.collection.convert.decorateAsScala._ */ class BackendUtils[BT <: BTypes](val btypes: BT) { import btypes._ + import callGraph.ClosureInstantiation /** * A wrapper to make ASM's Analyzer a bit easier to use. @@ -141,6 +143,14 @@ class BackendUtils[BT <: BTypes](val btypes: BT) { (result, map, hasSerializableClosureInstantiation) } + def getBoxedUnit: FieldInsnNode = new FieldInsnNode(Opcodes.GETSTATIC, coreBTypes.srBoxedUnitRef.internalName, "UNIT", coreBTypes.srBoxedUnitRef.descriptor) + + private val anonfunAdaptedName = """.*\$anonfun\$\d+\$adapted""" + def hasAdaptedImplMethod(closureInit: ClosureInstantiation): Boolean = { + BytecodeUtils.isrJFunctionType(Type.getReturnType(closureInit.lambdaMetaFactoryCall.indy.desc).getInternalName) && + closureInit.lambdaMetaFactoryCall.implMethod.getName.matches(anonfunAdaptedName) + } + /** * Visit the class node and collect all referenced nested classes. */ diff --git a/src/compiler/scala/tools/nsc/backend/jvm/opt/CallGraph.scala b/src/compiler/scala/tools/nsc/backend/jvm/opt/CallGraph.scala index b192e1b46a..64677ddcc0 100644 --- a/src/compiler/scala/tools/nsc/backend/jvm/opt/CallGraph.scala +++ b/src/compiler/scala/tools/nsc/backend/jvm/opt/CallGraph.scala @@ -461,7 +461,7 @@ class CallGraph[BT <: BTypes](val btypes: BT) { // When re-writing the closure callsite to the implMethod, we have to insert a cast. // // The check below ensures that - // (1) the implMethod type has the expected singature (captured types plus argument types + // (1) the implMethod type has the expected signature (captured types plus argument types // from instantiatedMethodType) // (2) the receiver of the implMethod matches the first captured type // (3) all parameters that are not the same in samMethodType and instantiatedMethodType diff --git a/src/compiler/scala/tools/nsc/backend/jvm/opt/ClosureOptimizer.scala b/src/compiler/scala/tools/nsc/backend/jvm/opt/ClosureOptimizer.scala index 4203a93f2e..4e1e878aa8 100644 --- a/src/compiler/scala/tools/nsc/backend/jvm/opt/ClosureOptimizer.scala +++ b/src/compiler/scala/tools/nsc/backend/jvm/opt/ClosureOptimizer.scala @@ -11,7 +11,7 @@ import scala.annotation.switch import scala.collection.immutable import scala.collection.immutable.IntMap import scala.reflect.internal.util.NoPosition -import scala.tools.asm.{Type, Opcodes} +import scala.tools.asm.{Handle, Type, Opcodes} import scala.tools.asm.tree._ import scala.tools.nsc.backend.jvm.BTypes.InternalName import BytecodeUtils._ @@ -23,7 +23,9 @@ import scala.collection.convert.decorateAsScala._ class ClosureOptimizer[BT <: BTypes](val btypes: BT) { import btypes._ import callGraph._ + import coreBTypes._ import backendUtils._ + import ClosureOptimizer._ /** * If a closure is allocated and invoked within the same method, re-write the invocation to the @@ -81,6 +83,7 @@ class ClosureOptimizer[BT <: BTypes](val btypes: BT) { // We don't need to worry about the method being too large for running an analysis: large // methods are not added to the call graph / closureInstantiations map. lazy val prodCons = new ProdConsAnalyzer(methodNode, closureInits.valuesIterator.next().ownerClass.internalName) + // sorting for bytecode stability (e.g. indices of local vars created during the rewrite) val sortedInits = immutable.TreeSet.empty ++ closureInits.values sortedInits.iterator.map(init => (init, closureCallsites(init, prodCons))).filter(_._2.nonEmpty) }).toList // mapping to a list (not a map) to keep the sorting @@ -118,20 +121,7 @@ class ClosureOptimizer[BT <: BTypes](val btypes: BT) { val argTypes = closureInit.lambdaMetaFactoryCall.samMethodType.getArgumentTypes val firstArgLocal = ownerMethod.maxLocals - // The comment in the unapply method of `LambdaMetaFactoryCall` explains why we have to introduce - // casts for arguments that have different types in samMethodType and instantiatedMethodType. - val castLoadTypes = { - val instantiatedMethodType = closureInit.lambdaMetaFactoryCall.instantiatedMethodType - (argTypes, instantiatedMethodType.getArgumentTypes).zipped map { - case (samArgType, instantiatedArgType) if samArgType != instantiatedArgType => - // the LambdaMetaFactoryCall extractor ensures that the two types are reference types, - // so we don't end up casting primitive values. - Some(instantiatedArgType) - case _ => - None - } - } - val argLocals = LocalsList.fromTypes(firstArgLocal, argTypes, castLoadTypes) + val argLocals = LocalsList.fromTypes(firstArgLocal, argTypes) ownerMethod.maxLocals = firstArgLocal + argLocals.size (captureLocals, argLocals) @@ -169,6 +159,28 @@ class ClosureOptimizer[BT <: BTypes](val btypes: BT) { }).toList } + /** + * Check whether `invocation` invokes the SAM of the IndyLambda `closureInit`. + * + * In addition to a perfect match, we also identify cases where a generic FunctionN is created + * but the invocation is to a specialized variant apply$sp... Vice-versa, we also allow the + * case where a specialized FunctionN$sp.. is created but the generic apply is invoked. In + * these cases, the translation will introduce the necessary box / unbox invocations. Example: + * + * val f: Int => Any = (x: Int) => 1 + * f(10) + * + * The IndyLambda creates a specialized `JFunction1$mcII$sp`, whose SAM is `apply$mcII$sp(I)I`. + * The invocation calls `apply(Object)Object`: the method name and type don't match. + * We identify these cases, insert the necessary unbox operation for the arguments, and invoke + * the `$anonfun(I)I` method. + * + * Tests in InlinerTest.optimizeSpecializedClosures. In that test, methods t4/t4a/t5/t8 show + * examples where the parameters have to be unboxed because generic `apply` is called, but the + * lambda body method takes primitive types. + * The opposite case is in t9: a the specialized `apply$sp..` is invoked, but the lambda body + * method takes boxed arguments, so we have to insert boxing operations. + */ private def isSamInvocation(invocation: MethodInsnNode, closureInit: ClosureInstantiation, prodCons: => ProdConsAnalyzer): Boolean = { val indy = closureInit.lambdaMetaFactoryCall.indy if (invocation.getOpcode == INVOKESTATIC) false @@ -183,11 +195,97 @@ class ClosureOptimizer[BT <: BTypes](val btypes: BT) { receiverProducers.size == 1 && receiverProducers.head == indy } - invocation.name == indy.name && { - val indySamMethodDesc = closureInit.lambdaMetaFactoryCall.samMethodType.getDescriptor - indySamMethodDesc == invocation.desc - } && - closureIsReceiver // most expensive check last + def isSpecializedVersion(specName: String, nonSpecName: String) = specName.startsWith(nonSpecName) && specName.substring(nonSpecName.length).matches(specializationSuffix) + + def sameOrSpecializedType(specTp: Type, nonSpecTp: Type) = { + specTp == nonSpecTp || { + val specDesc = specTp.getDescriptor + val nonSpecDesc = nonSpecTp.getDescriptor + specDesc.length == 1 && primitives.contains(specDesc) && nonSpecDesc == ObjectRef.descriptor + } + } + + def specializedDescMatches(specMethodDesc: String, nonSpecMethodDesc: String) = { + val specArgs = Type.getArgumentTypes(specMethodDesc) + val nonSpecArgs = Type.getArgumentTypes(nonSpecMethodDesc) + specArgs.corresponds(nonSpecArgs)(sameOrSpecializedType) && sameOrSpecializedType(Type.getReturnType(specMethodDesc), Type.getReturnType(nonSpecMethodDesc)) + } + + def nameAndDescMatch = { + val aName = invocation.name + val bName = indy.name + val aDesc = invocation.desc + val bDesc = closureInit.lambdaMetaFactoryCall.samMethodType.getDescriptor + if (aName == bName) aDesc == bDesc + else if (isSpecializedVersion(aName, bName)) specializedDescMatches(aDesc, bDesc) + else if (isSpecializedVersion(bName, aName)) specializedDescMatches(bDesc, aDesc) + else false + } + + nameAndDescMatch && closureIsReceiver // most expensive check last + } + } + + private def isPrimitiveType(asmType: Type) = { + val sort = asmType.getSort + Type.VOID <= sort && sort <= Type.DOUBLE + } + + private def unboxOp(primitiveType: Type): MethodInsnNode = { + val bType = bTypeForDescriptorOrInternalNameFromClassfile(primitiveType.getDescriptor) + val MethodNameAndType(name, methodBType) = asmUnboxTo(bType) + new MethodInsnNode(INVOKESTATIC, srBoxesRunTimeRef.internalName, name, methodBType.descriptor, /*itf =*/ false) + } + + private def boxOp(primitiveType: Type): MethodInsnNode = { + val bType = bTypeForDescriptorOrInternalNameFromClassfile(primitiveType.getDescriptor) + val MethodNameAndType(name, methodBType) = asmBoxTo(bType) + new MethodInsnNode(INVOKESTATIC, srBoxesRunTimeRef.internalName, name, methodBType.descriptor, /*itf =*/ false) + } + + /** + * The argument types of the lambda body method may differ in two ways from the argument types of + * the closure member method that is invoked (and replaced by a call to the body). + * - The lambda body method may have more specific types than the invoked closure member, see + * comment in [[LambdaMetaFactoryCall.unapply]]. + * - The invoked closure member might be a specialized variant of the SAM or vice-versa, see + * comment method [[isSamInvocation]]. + */ + private def adaptStoredArguments(closureInit: ClosureInstantiation, invocation: MethodInsnNode): Int => Option[AbstractInsnNode] = { + val invokeDesc = invocation.desc + // The lambda body method has additional parameters for captured values. Here we need to consider + // only those parameters of the body method that correspond to lambda parameters. This happens + // to be exactly LMF.instantiatedMethodType. In fact, `LambdaMetaFactoryCall.unapply` ensures + // that the body method signature is exactly (capturedParams + instantiatedMethodType). + val lambdaBodyMethodDescWithoutCaptures = closureInit.lambdaMetaFactoryCall.instantiatedMethodType.getDescriptor + if (invokeDesc == lambdaBodyMethodDescWithoutCaptures) { + _ => None + } else { + val invokeArgTypes = Type.getArgumentTypes(invokeDesc) + val implMethodArgTypes = Type.getArgumentTypes(lambdaBodyMethodDescWithoutCaptures) + val res = new Array[Option[AbstractInsnNode]](invokeArgTypes.length) + for (i <- invokeArgTypes.indices) { + if (invokeArgTypes(i) == implMethodArgTypes(i)) { + res(i) = None + } else if (isPrimitiveType(implMethodArgTypes(i)) && invokeArgTypes(i).getDescriptor == ObjectRef.descriptor) { + res(i) = Some(unboxOp(implMethodArgTypes(i))) + } else if (isPrimitiveType(invokeArgTypes(i)) && implMethodArgTypes(i).getDescriptor == ObjectRef.descriptor) { + res(i) = Some(boxOp(invokeArgTypes(i))) + } else { + assert(!isPrimitiveType(invokeArgTypes(i)), invokeArgTypes(i)) + assert(!isPrimitiveType(implMethodArgTypes(i)), implMethodArgTypes(i)) + // The comment in the unapply method of `LambdaMetaFactoryCall` explains why we have to introduce + // casts for arguments that have different types in samMethodType and instantiatedMethodType. + // + // Note: + // - invokeArgTypes is the same as the argument types in the IndyLambda's samMethodType, + // this is ensured by the `isSamInvocation` filter in this file + // - implMethodArgTypes is the same as the arg types in the IndyLambda's instantiatedMethodType, + // this is ensured by the unapply method in LambdaMetaFactoryCall (file CallGraph) + res(i) = Some(new TypeInsnNode(CHECKCAST, implMethodArgTypes(i).getInternalName)) + } + } + res } } @@ -196,7 +294,7 @@ class ClosureOptimizer[BT <: BTypes](val btypes: BT) { val lambdaBodyHandle = closureInit.lambdaMetaFactoryCall.implMethod // store arguments - insertStoreOps(invocation, ownerMethod, argumentLocalsList) + insertStoreOps(invocation, ownerMethod, argumentLocalsList, adaptStoredArguments(closureInit, invocation)) // drop the closure from the stack ownerMethod.instructions.insertBefore(invocation, new InsnNode(POP)) @@ -228,8 +326,22 @@ class ClosureOptimizer[BT <: BTypes](val btypes: BT) { val bodyInvocation = new MethodInsnNode(bodyOpcode, lambdaBodyHandle.getOwner, lambdaBodyHandle.getName, lambdaBodyHandle.getDesc, isInterface) ownerMethod.instructions.insertBefore(invocation, bodyInvocation) - val returnType = Type.getReturnType(lambdaBodyHandle.getDesc) - fixLoadedNothingOrNullValue(returnType, bodyInvocation, ownerMethod, btypes) // see comment of that method + val bodyReturnType = Type.getReturnType(lambdaBodyHandle.getDesc) + val invocationReturnType = Type.getReturnType(invocation.desc) + if (isPrimitiveType(invocationReturnType) && bodyReturnType.getDescriptor == ObjectRef.descriptor) { + val op = + if (invocationReturnType.getSort == Type.VOID) getPop(1) + else unboxOp(invocationReturnType) + ownerMethod.instructions.insertBefore(invocation, op) + } else if (isPrimitiveType(bodyReturnType) && invocationReturnType.getDescriptor == ObjectRef.descriptor) { + val op = + if (bodyReturnType.getSort == Type.VOID) getBoxedUnit + else boxOp(bodyReturnType) + ownerMethod.instructions.insertBefore(invocation, op) + } else { + // see comment of that method + fixLoadedNothingOrNullValue(bodyReturnType, bodyInvocation, ownerMethod, btypes) + } ownerMethod.instructions.remove(invocation) @@ -277,6 +389,9 @@ class ClosureOptimizer[BT <: BTypes](val btypes: BT) { // Rewriting a closure invocation may render code unreachable. For example, the body method of // (x: T) => ??? has return type Nothing$, and an ATHROW is added (see fixLoadedNothingOrNullValue). unreachableCodeEliminated -= ownerMethod + + if (hasAdaptedImplMethod(closureInit) && inliner.canInlineBody(bodyMethodCallsite).isEmpty) + inliner.inlineCallsite(bodyMethodCallsite) } /** @@ -293,13 +408,10 @@ class ClosureOptimizer[BT <: BTypes](val btypes: BT) { // local. On the other hand, further optimizations (copy propagation, remove unused locals) will // clean it up. - // Captured variables don't need to be cast when loaded at the callsite (castLoadTypes are None). - // This is checked in `isClosureInstantiation`: the types of the captured variables in the indy - // instruction match exactly the corresponding parameter types in the body method. - val localsForCaptures = LocalsList.fromTypes(firstCaptureLocal, capturedTypes, castLoadTypes = _ => None) + val localsForCaptures = LocalsList.fromTypes(firstCaptureLocal, capturedTypes) closureInit.ownerMethod.maxLocals = firstCaptureLocal + localsForCaptures.size - insertStoreOps(indy, closureInit.ownerMethod, localsForCaptures) + insertStoreOps(indy, closureInit.ownerMethod, localsForCaptures, _ => None) insertLoadOps(indy, closureInit.ownerMethod, localsForCaptures) localsForCaptures @@ -311,8 +423,16 @@ class ClosureOptimizer[BT <: BTypes](val btypes: BT) { * * The lowest stack value is stored in the head of the locals list, so the last local is stored first. */ - private def insertStoreOps(before: AbstractInsnNode, methodNode: MethodNode, localsList: LocalsList) = - insertLocalValueOps(before, methodNode, localsList, store = true) + private def insertStoreOps(before: AbstractInsnNode, methodNode: MethodNode, localsList: LocalsList, beforeStore: Int => Option[AbstractInsnNode]) = { + // The first instruction needs to store into the last local of the `localsList`. + // To avoid reversing the list, we use `insert(previous)`. + val previous = before.getPrevious + def ins(op: AbstractInsnNode) = methodNode.instructions.insert(previous, op) + for ((l, i) <- localsList.locals.zipWithIndex) { + ins(new VarInsnNode(l.storeOpcode, l.local)) + beforeStore(i) foreach ins + } + } /** * Insert load operations in front of the `before` instruction to copy the local values denoted @@ -320,20 +440,10 @@ class ClosureOptimizer[BT <: BTypes](val btypes: BT) { * * The head of the locals list will be the lowest value on the stack, so the first local is loaded first. */ - private def insertLoadOps(before: AbstractInsnNode, methodNode: MethodNode, localsList: LocalsList) = - insertLocalValueOps(before, methodNode, localsList, store = false) - - private def insertLocalValueOps(before: AbstractInsnNode, methodNode: MethodNode, localsList: LocalsList, store: Boolean): Unit = { - // If `store` is true, the first instruction needs to store into the last local of the `localsList`. - // Load instructions on the other hand are emitted in the order of the list. - // To avoid reversing the list, we use `insert(previousInstr)` for stores and `insertBefore(before)` for loads. - lazy val previous = before.getPrevious + private def insertLoadOps(before: AbstractInsnNode, methodNode: MethodNode, localsList: LocalsList) = { for (l <- localsList.locals) { - val varOp = new VarInsnNode(if (store) l.storeOpcode else l.loadOpcode, l.local) - if (store) methodNode.instructions.insert(previous, varOp) - else methodNode.instructions.insertBefore(before, varOp) - if (!store) for (castType <- l.castLoadedValue) - methodNode.instructions.insert(varOp, new TypeInsnNode(CHECKCAST, castType.getInternalName)) + val op = new VarInsnNode(l.loadOpcode, l.local) + methodNode.instructions.insertBefore(before, op) } } @@ -355,12 +465,12 @@ class ClosureOptimizer[BT <: BTypes](val btypes: BT) { * Local(6, refOpOffset) :: * Nil */ - def fromTypes(firstLocal: Int, types: Array[Type], castLoadTypes: Int => Option[Type]): LocalsList = { + def fromTypes(firstLocal: Int, types: Array[Type]): LocalsList = { var sizeTwoOffset = 0 val locals: List[Local] = types.indices.map(i => { // The ASM method `type.getOpcode` returns the opcode for operating on a value of `type`. val offset = types(i).getOpcode(ILOAD) - ILOAD - val local = Local(firstLocal + i + sizeTwoOffset, offset, castLoadTypes(i)) + val local = Local(firstLocal + i + sizeTwoOffset, offset) if (local.size == 2) sizeTwoOffset += 1 local })(collection.breakOut) @@ -374,10 +484,15 @@ class ClosureOptimizer[BT <: BTypes](val btypes: BT) { * The xLOAD / xSTORE opcodes are in the following sequence: I, L, F, D, A, so the offset for * a local variable holding a reference (`A`) is 4. See also method `getOpcode` in [[scala.tools.asm.Type]]. */ - case class Local(local: Int, opcodeOffset: Int, castLoadedValue: Option[Type]) { + case class Local(local: Int, opcodeOffset: Int) { def size = if (loadOpcode == LLOAD || loadOpcode == DLOAD) 2 else 1 def loadOpcode = ILOAD + opcodeOffset def storeOpcode = ISTORE + opcodeOffset } } + +object ClosureOptimizer { + val primitives = "BSIJCFDZV" + val specializationSuffix = s"(\\$$mc[$primitives]+\\$$sp)" +} diff --git a/test/junit/scala/tools/nsc/backend/jvm/opt/ClosureOptimizerTest.scala b/test/junit/scala/tools/nsc/backend/jvm/opt/ClosureOptimizerTest.scala index 54724458e2..99041b5497 100644 --- a/test/junit/scala/tools/nsc/backend/jvm/opt/ClosureOptimizerTest.scala +++ b/test/junit/scala/tools/nsc/backend/jvm/opt/ClosureOptimizerTest.scala @@ -70,4 +70,21 @@ class ClosureOptimizerTest extends ClearAfterClass { assert(bodyCall.getNext.getOpcode == POP) assert(bodyCall.getNext.getNext.getOpcode == ACONST_NULL) } + + @Test + def makeLMFCastExplicit(): Unit = { + val code = + """class C { + | def t(l: List[String]) = { + | val fun: String => String = s => s + | fun(l.head) + | } + |} + """.stripMargin + val List(c) = compileClasses(compiler)(code) + assertSameCode(getSingleMethod(c, "t").instructions.dropNonOp, + List(VarOp(ALOAD, 1), Invoke(INVOKEVIRTUAL, "scala/collection/immutable/List", "head", "()Ljava/lang/Object;", false), + TypeOp(CHECKCAST, "java/lang/String"), Invoke(INVOKESTATIC, "C", "C$$$anonfun$1", "(Ljava/lang/String;)Ljava/lang/String;", false), + TypeOp(CHECKCAST, "java/lang/String"), Op(ARETURN))) + } } diff --git a/test/junit/scala/tools/nsc/backend/jvm/opt/InlinerTest.scala b/test/junit/scala/tools/nsc/backend/jvm/opt/InlinerTest.scala index 1037fd5221..75c1a0d3ad 100644 --- a/test/junit/scala/tools/nsc/backend/jvm/opt/InlinerTest.scala +++ b/test/junit/scala/tools/nsc/backend/jvm/opt/InlinerTest.scala @@ -1226,4 +1226,194 @@ class InlinerTest extends ClearAfterClass { assertNoInvoke(getSingleMethod(c, "g")) assertNoInvoke(getSingleMethod(d, "t")) } + + @Test + def optimizeSpecializedClosures(): Unit = { + val code = + """class ValKl(val x: Int) extends AnyVal + | + |class C { + | def t1 = { + | // IndyLambda: SAM type is JFunction1$mcII$sp, SAM is apply$mcII$sp(I)I, body method is $anonfun(I)I + | val f = (x: Int) => x + 1 + | // invocation of apply$mcII$sp(I)I, matches the SAM in IndyLambda. no boxing / unboxing needed. + | f(10) + | // opt: re-write the invocation to the body method + | } + | + | @inline final def m1a(f: Long => Int) = f(1l) + | def t1a = m1a(l => l.toInt) // after inlining m1a, we have the same situation as in t1 + | + | def t2 = { + | // there is no specialized variant of Function2 for this combination of types, so the IndyLambda has to create a generic Function2. + | // IndyLambda: SAM type is JFunction2, SAM is apply(ObjectObject)Object, body method is $anonfun$adapted(ObjectObject)Object + | val f = (b: Byte, i: Int) => i + b + | // invocation of apply(ObjectOjbect)Object, matches SAM in IndyLambda. arguments are boxed, result unboxed. + | f(1, 2) + | // opt: re-wrtie to $anonfun$adapted + | // inline that call, then we get box-unbox pairs (can be eliminated) and a call to $anonfun(BI)I + | } + | + | def t3 = { + | // similar to t2: for functions with value class parameters, IndyLambda always uses the generic Function version. + | // IndyLambda: SAM type is JFunction1, SAM is apply(Object)Object, body method is $anonfun$adapted(Object)Object + | val f = (a: ValKl) => a + | // invocation of apply(Object)Object, ValKl instance is created, result extracted + | f(new ValKl(1)) + | // opt: re-write to $anonfun$adapted. + | // inline that call, then we get value class instantiation-extraction pairs and a call to $anonfun(I)I + | } + | + | def t4 = { + | // IndyLambda: SAM type is JFunction1$mcII$sp, SAM is apply$mcII$sp(I)I, body method is $anonfun(I)I + | val f: Int => Any = (x: Int) => 1 + | // invocation of apply(Object)Object, argument is boxed. method name and type doesn't match IndyLambda. + | f(10) + | // opt: rewriting to the body method requires inserting an unbox operation for the argument, and a box operation for the result + | // that produces a box-unbox pair and a call to $anonfun(I)I + | } + | + | + | @inline final def m4a[T, U, V](f: (T, U) => V, x: T, y: U) = f(x, y) // invocation to generic apply(ObjectObject)Object + | def t4a = m4a((x: Int, y: Double) => 1l + x + y.toLong, 1, 2d) // IndyLambda uses specilized JFunction2$mcJID$sp. after inlining m4a, similar to t4. + | + | def t5 = { + | // no specialization for the comibnation of primitives + | // IndyLambda: SAM type is JFunction2, SAM is generic apply, body method is $anonfun$adapted + | val f: (Int, Byte) => Any = (x: Int, b: Byte) => 1 + | // invocation of generic apply. + | f(10, 3) + | // opt: re-write to $anonfun$adapted, inline that method. generates box-unbox pairs and a call to $anonfun(IB)I + | } + | + | def t5a = m4a((x: Int, y: Byte) => 1, 12, 31.toByte) // similar to t5 after inlining m4a + | + | // m6$mIVc$sp invokes apply$mcVI$sp + | @inline final def m6[@specialized(Int) T, @specialized(Unit) U](f: T => U, x: T): Unit = f(x) + | // IndyLambda: JFunction1$mcVI$sp, SAM is apply$mcVI$sp, body method $anonfun(I)V + | // invokes m6$mIVc$sp (Lscala/Function1;I)V + | def t6 = m6((x: Int) => (), 10) + | // opt: after inlining m6, the closure method invocation (apply$mcVI$sp) matches the IndyLambda, the call can be rewritten, no boxing + | + | // m7 invokes apply + | @inline final def m7[@specialized(Boolean) T, @specialized(Int) U](f: T => U, x: T): Unit = f(x) + | // IndyLambda: JFunction1, SAM is apply(Object)Object, body method is $anonfun$adapted(Obj)Obj + | // `true` is boxed before passing to m7 + | def t7 = m7((x: Boolean) => (), true) + | // opt: after inlining m7, the apply call is re-written to $anonfun$adapted, which is then inlined. + | // we get a box-unbox pair and a call to $anonfun(Z)V + | + | + | // invokes the generic apply(ObjObj)Obj + | @inline final def m8[T, U, V](f: (T, U) => V, x: T, y: U) = f(x, y) + | // IndyLambda: JFunction2$mcJID$sp, SAM is apply$mcJID$sp, body method $anonfun(ID)J + | // boxes the int and double arguments and calls m8, unboxToLong the result + | def t8 = m8((x: Int, y: Double) => 1l + x + y.toLong, 1, 2d) + | // opt: after inlining m8, rewrite to the body method $anonfun(ID)J, which requires inserting unbox operations for the params, box for the result + | // the box-unbox pairs can then be optimized away + | + | // m9$mVc$sp invokes apply$mcVI$sp + | @inline final def m9[@specialized(Unit) U](f: Int => U): Unit = f(1) + | // IndyLambda: JFunction1, SAM is apply(Obj)Obj, body method $anonfun$adapted(Ojb)Obj + | // invocation of m9$mVc$sp + | def t9 = m9(println) + | // opt: after inlining m9, rewrite to $anonfun$adapted(Ojb)Obj, which requires inserting a box operation for the parameter. + | // then we inline $adapted, which has signature (Obj)V. the `BoxedUnit.UNIT` from the body of $anonfun$adapted is eliminated by push-pop + | + | def t9a = (1 to 10) foreach println // similar to t9 + | + | def intCons(i: Int): Unit = () + | // IndyLambda: JFunction1$mcVI$sp, SAM is apply$mcVI$sp, body method $anonfun(I)V + | def t10 = m9(intCons) + | // after inlining m9, rewrite the apply$mcVI$sp call to the body method, no adaptations required + | + | def t10a = (1 to 10) foreach intCons // similar to t10 + |} + """.stripMargin + val List(c, _, _) = compile(code) + + def instructionSummary(m: Method): List[Any] = m.instructions.dropNonOp map { + case i: Invoke => i.name + case i => i.opcode + } + + assertEquals(instructionSummary(getSingleMethod(c, "t1")), + List(BIPUSH, "C$$$anonfun$1", IRETURN)) + + assertEquals(instructionSummary(getSingleMethod(c, "t1a")), + List(LCONST_1, "C$$$anonfun$2", IRETURN)) + + assertEquals(instructionSummary(getSingleMethod(c, "t2")), List( + ICONST_1, "boxToByte", + ICONST_2, "boxToInteger", ASTORE, + "unboxToByte", + ALOAD, "unboxToInt", + "C$$$anonfun$3", + "boxToInteger", "unboxToInt", IRETURN)) + + // val a = new ValKl(n); new ValKl(anonfun(a.x)).x + // value class instantiation-extraction should be optimized by boxing elim + assertEquals(instructionSummary(getSingleMethod(c, "t3")), List( + NEW, DUP, ICONST_1, "<init>", ASTORE, + NEW, DUP, ALOAD, CHECKCAST, "x", + "C$$$anonfun$4", + "<init>", CHECKCAST, + "x", IRETURN)) + + assertEquals(instructionSummary(getSingleMethod(c, "t4")), List( + BIPUSH, "boxToInteger", "unboxToInt", + "C$$$anonfun$5", + "boxToInteger", ARETURN)) + + assertEquals(instructionSummary(getSingleMethod(c, "t4a")), List( + ICONST_1, "boxToInteger", + LDC, "boxToDouble", "unboxToDouble", DSTORE, + "unboxToInt", DLOAD, "C$$$anonfun$6", + "boxToLong", "unboxToLong", LRETURN)) + + assertEquals(instructionSummary(getSingleMethod(c, "t5")), List( + BIPUSH, "boxToInteger", + ICONST_3, "boxToByte", ASTORE, + "unboxToInt", ALOAD, + "unboxToByte", + "C$$$anonfun$7", + "boxToInteger", ARETURN)) + + assertEquals(instructionSummary(getSingleMethod(c, "t5a")), List( + BIPUSH, "boxToInteger", + BIPUSH, I2B, "boxToByte", ASTORE, + "unboxToInt", ALOAD, + "unboxToByte", + "C$$$anonfun$8", + "boxToInteger", "unboxToInt", IRETURN)) + + assertEquals(instructionSummary(getSingleMethod(c, "t6")), List( + BIPUSH, "C$$$anonfun$9", RETURN)) + + assertEquals(instructionSummary(getSingleMethod(c, "t7")), List( + ICONST_1, "boxToBoolean", "unboxToBoolean", + "C$$$anonfun$10", RETURN)) + + assertEquals(instructionSummary(getSingleMethod(c, "t8")), List( + ICONST_1, "boxToInteger", + LDC, "boxToDouble", "unboxToDouble", DSTORE, + "unboxToInt", DLOAD, "C$$$anonfun$11", + "boxToLong", "unboxToLong", LRETURN)) + + assertEquals(instructionSummary(getSingleMethod(c, "t9")), List( + ICONST_1, "boxToInteger", "C$$$anonfun$12", RETURN)) + + // t9a inlines Range.foreach, which is quite a bit of code, so just testing the core + assertInvoke(getSingleMethod(c, "t9a"), "C", "C$$$anonfun$13") + assert(instructionSummary(getSingleMethod(c, "t9a")).contains("boxToInteger")) + + assertEquals(instructionSummary(getSingleMethod(c, "t10")), List( + ICONST_1, ISTORE, + ALOAD, ILOAD, + "C$$$anonfun$14", RETURN)) + + // t10a inlines Range.foreach + assertInvoke(getSingleMethod(c, "t10a"), "C", "C$$$anonfun$15") + assert(!instructionSummary(getSingleMethod(c, "t10a")).contains("boxToInteger")) + } } |