| // Copyright (c) 2020, 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.analysis.inlining; |
| |
| import com.android.tools.r8.ir.analysis.type.Nullability; |
| import com.android.tools.r8.ir.analysis.type.TypeElement; |
| import com.android.tools.r8.ir.code.Instruction; |
| import com.android.tools.r8.ir.code.InvokeMethod; |
| import com.android.tools.r8.ir.code.Value; |
| import it.unimi.dsi.fastutil.ints.IntList; |
| |
| /** Constraint that is satisfied if a specific argument is always null. */ |
| public class NullSimpleInliningConstraint extends SimpleInliningArgumentConstraint { |
| |
| private final Nullability nullability; |
| |
| private NullSimpleInliningConstraint(int argumentIndex, Nullability nullability) { |
| super(argumentIndex); |
| assert nullability.isDefinitelyNull() || nullability.isDefinitelyNotNull(); |
| this.nullability = nullability; |
| } |
| |
| static NullSimpleInliningConstraint create( |
| int argumentIndex, Nullability nullability, SimpleInliningConstraintFactory witness) { |
| assert witness != null; |
| return new NullSimpleInliningConstraint(argumentIndex, nullability); |
| } |
| |
| @Override |
| public final boolean isSatisfied(InvokeMethod invoke) { |
| Value argument = getArgument(invoke); |
| TypeElement argumentType = argument.getType(); |
| assert argumentType.isReferenceType(); |
| |
| if (argumentType.nullability() == nullability) { |
| return true; |
| } |
| |
| // Take the root value to also deal with the following case, which may happen in dead code, |
| // where v1 is actually guaranteed to be null, despite the value's type being non-null: |
| // v0 <- ConstNumber 0 |
| // v1 <- AssumeNotNull v0 |
| return argument.isDefinedByInstructionSatisfying(Instruction::isAssume) |
| && argument.getAliasedValue().getType().nullability() == nullability; |
| } |
| |
| @Override |
| public SimpleInliningConstraint rewrittenWithUnboxedArguments( |
| IntList unboxedArgumentIndices, SimpleInliningConstraintFactory factory) { |
| if (unboxedArgumentIndices.contains(getArgumentIndex())) { |
| return nullability.isDefinitelyNull() |
| ? factory.createEqualToNumberConstraint(getArgumentIndex(), 0) |
| : factory.createNotEqualToNumberConstraint(getArgumentIndex(), 0); |
| } |
| return this; |
| } |
| |
| @Override |
| SimpleInliningArgumentConstraint withArgumentIndex( |
| int argumentIndex, SimpleInliningConstraintFactory factory) { |
| return factory.createNullConstraint(argumentIndex, nullability); |
| } |
| } |