| // Copyright (c) 2018, the R8 project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| package com.android.tools.r8.ir.optimize; |
| |
| import com.android.tools.r8.graph.Code; |
| import com.android.tools.r8.graph.DexClass; |
| import com.android.tools.r8.graph.DexEncodedMethod; |
| import com.android.tools.r8.graph.DexType; |
| import com.android.tools.r8.ir.analysis.type.TypeAnalysis; |
| import com.android.tools.r8.ir.code.BasicBlock; |
| import com.android.tools.r8.ir.code.IRCode; |
| import com.android.tools.r8.ir.code.InvokeMethod; |
| import com.android.tools.r8.ir.code.InvokeMethodWithReceiver; |
| import com.android.tools.r8.ir.code.InvokePolymorphic; |
| import com.android.tools.r8.ir.code.InvokeStatic; |
| import com.android.tools.r8.ir.code.Value; |
| import com.android.tools.r8.ir.conversion.CallSiteInformation; |
| import com.android.tools.r8.ir.optimize.Inliner.InlineAction; |
| import com.android.tools.r8.ir.optimize.Inliner.InlineeWithReason; |
| import com.android.tools.r8.ir.optimize.Inliner.Reason; |
| import com.android.tools.r8.logging.Log; |
| import com.android.tools.r8.utils.InternalOptions; |
| import com.android.tools.r8.utils.IteratorUtils; |
| import java.util.BitSet; |
| import java.util.List; |
| import java.util.ListIterator; |
| import java.util.Set; |
| import java.util.function.Predicate; |
| |
| final class DefaultInliningOracle implements InliningOracle, InliningStrategy { |
| |
| private final Inliner inliner; |
| private final DexEncodedMethod method; |
| private final IRCode code; |
| private final CallSiteInformation callSiteInformation; |
| private final Predicate<DexEncodedMethod> isProcessedConcurrently; |
| private final InliningInfo info; |
| private final InternalOptions options; |
| private final int inliningInstructionLimit; |
| private int instructionAllowance; |
| |
| DefaultInliningOracle( |
| Inliner inliner, |
| DexEncodedMethod method, |
| IRCode code, |
| CallSiteInformation callSiteInformation, |
| Predicate<DexEncodedMethod> isProcessedConcurrently, |
| InternalOptions options, |
| int inliningInstructionLimit, |
| int inliningInstructionAllowance) { |
| this.inliner = inliner; |
| this.method = method; |
| this.code = code; |
| this.callSiteInformation = callSiteInformation; |
| this.isProcessedConcurrently = isProcessedConcurrently; |
| info = Log.ENABLED ? new InliningInfo(method) : null; |
| this.options = options; |
| this.inliningInstructionLimit = inliningInstructionLimit; |
| this.instructionAllowance = inliningInstructionAllowance; |
| } |
| |
| @Override |
| public void finish() { |
| if (Log.ENABLED) { |
| Log.debug(getClass(), info.toString()); |
| } |
| } |
| |
| private DexEncodedMethod validateCandidate(InvokeMethod invoke, DexType invocationContext) { |
| DexEncodedMethod candidate = invoke.lookupSingleTarget(inliner.appInfo, invocationContext); |
| if ((candidate == null) |
| || (candidate.getCode() == null) |
| || inliner.appInfo.definitionFor(candidate.method.getHolder()).isLibraryClass()) { |
| if (info != null) { |
| info.exclude(invoke, "No inlinee"); |
| } |
| return null; |
| } |
| // Ignore the implicit receiver argument. |
| int numberOfArguments = |
| invoke.arguments().size() - (invoke.isInvokeMethodWithReceiver() ? 1 : 0); |
| if (numberOfArguments != candidate.method.getArity()) { |
| if (info != null) { |
| info.exclude(invoke, "Argument number mismatch"); |
| } |
| return null; |
| } |
| return candidate; |
| } |
| |
| private Reason computeInliningReason(DexEncodedMethod target) { |
| if (target.getOptimizationInfo().forceInline() |
| || (inliner.appInfo.hasLiveness() |
| && inliner.appInfo.withLiveness().forceInline.contains(target.method))) { |
| return Reason.FORCE; |
| } |
| if (inliner.appInfo.hasLiveness() |
| && inliner.appInfo.withLiveness().alwaysInline.contains(target.method)) { |
| return Reason.ALWAYS; |
| } |
| if (callSiteInformation.hasSingleCallSite(target)) { |
| return Reason.SINGLE_CALLER; |
| } |
| if (isDoubleInliningTarget(target)) { |
| return Reason.DUAL_CALLER; |
| } |
| return Reason.SIMPLE; |
| } |
| |
| private boolean canInlineStaticInvoke(DexEncodedMethod method, DexEncodedMethod target) { |
| // Only proceed with inlining a static invoke if: |
| // - the holder for the target equals the holder for the method, or |
| // - the target method always triggers class initialization of its holder before any other side |
| // effect (hence preserving class initialization semantics). |
| // - there is no non-trivial class initializer. |
| DexType targetHolder = target.method.getHolder(); |
| if (method.method.getHolder() == targetHolder) { |
| return true; |
| } |
| DexClass clazz = inliner.appInfo.definitionFor(targetHolder); |
| assert clazz != null; |
| if (target.getOptimizationInfo().triggersClassInitBeforeAnySideEffect()) { |
| return true; |
| } |
| return classInitializationHasNoSideffects(targetHolder); |
| } |
| |
| /** |
| * Check for class initializer side effects when loading this class, as inlining might remove the |
| * load operation. |
| * <p> |
| * See https://docs.oracle.com/javase/specs/jvms/se9/html/jvms-5.html#jvms-5.5. |
| * <p> |
| * For simplicity, we are conservative and consider all interfaces, not only the ones with default |
| * methods. |
| */ |
| private boolean classInitializationHasNoSideffects(DexType classToCheck) { |
| DexClass clazz = inliner.appInfo.definitionFor(classToCheck); |
| if ((clazz == null) |
| || clazz.hasNonTrivialClassInitializer() |
| || clazz.defaultValuesForStaticFieldsMayTriggerAllocation()) { |
| return false; |
| } |
| for (DexType iface : clazz.interfaces.values) { |
| if (!classInitializationHasNoSideffects(iface)) { |
| return false; |
| } |
| } |
| return clazz.superType == null || classInitializationHasNoSideffects(clazz.superType); |
| } |
| |
| private synchronized boolean isDoubleInliningTarget(DexEncodedMethod candidate) { |
| // 10 is found from measuring. |
| return inliner.isDoubleInliningTarget(callSiteInformation, candidate) |
| && candidate.getCode().estimatedSizeForInliningAtMost(10); |
| } |
| |
| private boolean passesInliningConstraints(InvokeMethod invoke, DexEncodedMethod candidate, |
| Reason reason) { |
| if (candidate.getOptimizationInfo().neverInline()) { |
| return false; |
| } |
| |
| if (method == candidate) { |
| // Cannot handle recursive inlining at this point. |
| // Force inlined method should never be recursive. |
| assert !candidate.getOptimizationInfo().forceInline(); |
| if (info != null) { |
| info.exclude(invoke, "direct recursion"); |
| } |
| return false; |
| } |
| |
| if (reason != Reason.FORCE && isProcessedConcurrently.test(candidate)) { |
| if (info != null) { |
| info.exclude(invoke, "is processed in parallel"); |
| } |
| return false; |
| } |
| |
| if (options.testing.validInliningReasons != null |
| && !options.testing.validInliningReasons.contains(reason)) { |
| return false; |
| } |
| |
| // Abort inlining attempt if method -> target access is not right. |
| if (!inliner.hasInliningAccess(method, candidate)) { |
| if (info != null) { |
| info.exclude(invoke, "target does not have right access"); |
| } |
| return false; |
| } |
| |
| DexClass holder = inliner.appInfo.definitionFor(candidate.method.getHolder()); |
| if (holder.isInterface()) { |
| // Art978_virtual_interfaceTest correctly expects an IncompatibleClassChangeError exception at |
| // runtime. |
| if (info != null) { |
| info.exclude(invoke, "Do not inline target if method holder is an interface class"); |
| } |
| return false; |
| } |
| |
| if (holder.isLibraryClass()) { |
| // Library functions should not be inlined. |
| return false; |
| } |
| |
| // Don't inline if target is synchronized. |
| if (candidate.accessFlags.isSynchronized()) { |
| if (info != null) { |
| info.exclude(invoke, "target is synchronized"); |
| } |
| return false; |
| } |
| |
| // Attempt to inline a candidate that is only called twice. |
| if ((reason == Reason.DUAL_CALLER) && (inliner.doubleInlining(method, candidate) == null)) { |
| if (info != null) { |
| info.exclude(invoke, "target is not ready for double inlining"); |
| } |
| return false; |
| } |
| |
| if (reason == Reason.SIMPLE) { |
| // If we are looking for a simple method, only inline if actually simple. |
| Code code = candidate.getCode(); |
| int instructionLimit = computeInstructionLimit(invoke, candidate); |
| if (!code.estimatedSizeForInliningAtMost(instructionLimit)) { |
| if (info != null) { |
| info.exclude( |
| invoke, |
| "instruction limit exceeds: " |
| + code.estimatedSizeForInlining() |
| + " <= " |
| + instructionLimit); |
| } |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| private int computeInstructionLimit(InvokeMethod invoke, DexEncodedMethod candidate) { |
| int instructionLimit = inliningInstructionLimit; |
| BitSet hints = candidate.getOptimizationInfo().getKotlinNotNullParamHints(); |
| if (hints != null) { |
| List<Value> arguments = invoke.inValues(); |
| if (invoke.isInvokeMethodWithReceiver()) { |
| arguments = arguments.subList(1, arguments.size()); |
| } |
| for (int index = 0; index < arguments.size(); index++) { |
| Value argument = arguments.get(index); |
| if (argument.isNeverNull() && hints.get(index)) { |
| // 5-4 instructions per parameter check are expected to be removed. |
| instructionLimit += 4; |
| } |
| } |
| } |
| return instructionLimit; |
| } |
| |
| @Override |
| public InlineAction computeForInvokeWithReceiver( |
| InvokeMethodWithReceiver invoke, DexType invocationContext) { |
| DexEncodedMethod candidate = validateCandidate(invoke, invocationContext); |
| if (candidate == null || inliner.isBlackListed(candidate)) { |
| return null; |
| } |
| |
| // We can only inline an instance method call if we preserve the null check semantic (which |
| // would throw NullPointerException if the receiver is null). Therefore we can inline only if |
| // one of the following conditions is true: |
| // * the candidate inlinee checks null receiver before any side effect |
| // * the receiver is known to be non-null |
| boolean receiverIsNeverNull = !invoke.getReceiver().getTypeLattice().isNullable(); |
| if (!receiverIsNeverNull |
| && !candidate.getOptimizationInfo().checksNullReceiverBeforeAnySideEffect()) { |
| if (info != null) { |
| info.exclude(invoke, "receiver for candidate can be null"); |
| } |
| assert !inliner.appInfo.forceInline.contains(candidate.method); |
| return null; |
| } |
| |
| Reason reason = computeInliningReason(candidate); |
| if (!candidate.isInliningCandidate(method, reason, inliner.appInfo)) { |
| // Abort inlining attempt if the single target is not an inlining candidate. |
| if (info != null) { |
| info.exclude(invoke, "target is not identified for inlining"); |
| } |
| return null; |
| } |
| |
| if (!passesInliningConstraints(invoke, candidate, reason)) { |
| return null; |
| } |
| |
| if (info != null) { |
| info.include(invoke.getType(), candidate); |
| } |
| return new InlineAction(candidate, invoke, reason); |
| } |
| |
| @Override |
| public InlineAction computeForInvokeStatic(InvokeStatic invoke, DexType invocationContext) { |
| DexEncodedMethod candidate = validateCandidate(invoke, invocationContext); |
| if (candidate == null || inliner.isBlackListed(candidate)) { |
| return null; |
| } |
| |
| Reason reason = computeInliningReason(candidate); |
| // Determine if this should be inlined no matter how big it is. |
| if (!candidate.isInliningCandidate(method, reason, inliner.appInfo)) { |
| // Abort inlining attempt if the single target is not an inlining candidate. |
| if (info != null) { |
| info.exclude(invoke, "target is not identified for inlining"); |
| } |
| return null; |
| } |
| |
| // Abort inlining attempt if we can not guarantee class for static target has been initialized. |
| if (!canInlineStaticInvoke(method, candidate)) { |
| if (info != null) { |
| info.exclude(invoke, "target is static but we cannot guarantee class has been initialized"); |
| } |
| return null; |
| } |
| |
| if (!passesInliningConstraints(invoke, candidate, reason)) { |
| return null; |
| } |
| |
| if (info != null) { |
| info.include(invoke.getType(), candidate); |
| } |
| return new InlineAction(candidate, invoke, reason); |
| } |
| |
| @Override |
| public InlineAction computeForInvokePolymorphic( |
| InvokePolymorphic invoke, DexType invocationContext) { |
| // TODO: No inlining of invoke polymorphic for now. |
| if (info != null) { |
| info.exclude(invoke, "inlining through invoke signature polymorpic is not supported"); |
| } |
| return null; |
| } |
| |
| @Override |
| public void ensureMethodProcessed(DexEncodedMethod target, IRCode inlinee) { |
| if (!target.isProcessed()) { |
| if (Log.ENABLED) { |
| Log.verbose(getClass(), "Forcing extra inline on " + target.toSourceString()); |
| } |
| inliner.performInlining( |
| target, inlinee, isProcessedConcurrently, callSiteInformation); |
| } |
| } |
| |
| @Override |
| public boolean isValidTarget(InvokeMethod invoke, DexEncodedMethod target, IRCode inlinee) { |
| return !target.isInstanceInitializer() |
| || inliner.legalConstructorInline(method, invoke, inlinee); |
| } |
| |
| @Override |
| public boolean stillHasBudget() { |
| return instructionAllowance > 0; |
| } |
| |
| @Override |
| public boolean willExceedBudget(InlineeWithReason inlinee, BasicBlock block) { |
| if (inlinee.reason.mustBeInlined()) { |
| return false; |
| } |
| |
| if (block.hasCatchHandlers() && inlinee.reason != Reason.FORCE) { |
| // Inlining could lead to an explosion of move-exception and resolution moves. As an |
| // example, consider the following piece of code. |
| // try { |
| // ... |
| // foo(); |
| // ... |
| // } catch (A e) { ... } |
| // } catch (B e) { ... } |
| // } catch (C e) { ... } |
| // |
| // The generated code for the above example will have a move-exception instruction |
| // for each of the three catch handlers. Furthermore, the blocks with these move- |
| // exception instructions may require a number of resolution moves to setup the |
| // register state for the catch handlers. When inlining foo(), the generated code |
| // will have a move-exception instruction *for each of the instructions in foo() |
| // that can throw*, along with the necessary resolution moves for each exception- |
| // edge. We therefore abort inlining if the number of exception-edges explode. |
| int numberOfThrowingInstructionsInInlinee = 0; |
| for (BasicBlock inlineeBlock : inlinee.code.blocks) { |
| numberOfThrowingInstructionsInInlinee += inlineeBlock.numberOfThrowingInstructions(); |
| } |
| // Estimate the number of "control flow resolution blocks", where we will insert a |
| // move-exception instruction (if needed), along with all the resolution moves that |
| // will be needed to setup the register state for the catch handler. |
| int estimatedNumberOfControlFlowResolutionBlocks = |
| numberOfThrowingInstructionsInInlinee * block.numberOfCatchHandlers(); |
| // Abort if inlining could lead to an explosion in the number of control flow |
| // resolution blocks that setup the register state before the actual catch handler. |
| if (estimatedNumberOfControlFlowResolutionBlocks |
| >= options.inliningControlFlowResolutionBlocksThreshold) { |
| return true; |
| } |
| } |
| |
| // Allow the first method to consume more than the allowance to be inlined. |
| return instructionAllowance < 0; |
| } |
| |
| @Override |
| public void markInlined(InlineeWithReason inlinee) { |
| // TODO(118734615): All inlining use from the budget - should that only be SIMPLE? |
| instructionAllowance -= inliner.numberOfInstructions(inlinee.code); |
| } |
| |
| @Override |
| public void updateTypeInformationIfNeeded( |
| IRCode inlinee, ListIterator<BasicBlock> blockIterator, BasicBlock block) { |
| if (inliner.options.enableNonNullTracking) { |
| BasicBlock state = IteratorUtils.peekNext(blockIterator); |
| // Move the cursor back to where the first inlinee block was added. |
| while (blockIterator.hasPrevious() && blockIterator.previous() != block) { |
| // Do nothing. |
| } |
| assert IteratorUtils.peekNext(blockIterator) == block; |
| |
| // Kick off the tracker to add non-null IRs only to the inlinee blocks. |
| Set<Value> nonNullValues = new NonNullTracker() |
| .addNonNullInPart(code, blockIterator, inlinee.blocks::contains); |
| assert !blockIterator.hasNext(); |
| |
| // Restore the old state of the iterator. |
| while (blockIterator.hasPrevious() && blockIterator.previous() != state) { |
| // Do nothing. |
| } |
| assert IteratorUtils.peekNext(blockIterator) == state; |
| // TODO(b/72693244): could be done when Value is created. |
| new TypeAnalysis(inliner.appInfo, code.method).narrowing(nonNullValues); |
| } |
| // TODO(b/72693244): need a test where refined env in inlinee affects the caller. |
| } |
| |
| @Override |
| public DexType getReceiverTypeIfKnown(InvokeMethod invoke) { |
| return null; // Maybe improve later. |
| } |
| } |
